Review of Transition Metal Nitrides and Transition Metal Nitrides/Carbon nanocomposites for supercapacitor electrodes
過渡金屬氮化物和過渡金屬氮化物/碳納米複合材料用於超級電容器電極的研究進展

2.1. Hydrothermal method 2.1. 水熱法

The hydrothermal method is to synthesize TMN electrodes with different morphology and nanostructures at high pressure and medium temperature in a closed Teflon-lined stainless steel autoclave [76], which is considered a promising preparation method, due to its monodispersed particles with controllable size and morphology, versatility and environmental friendliness. Many TMN have been prepared by hydrothermal method [2,[77], [78], [79], [80], [81]] For example, Hou et al. [2] prepared chrysanthemum-like TiO₂ precursor by hydrothermal method, and then nitrided the precursor in order to obtain a novel chrysanthemum-like titanium nitride (CL-TiN), The prepared CL-TiN had a capacitance of 23.35 F g⁻¹ at 1.0 A g⁻¹, and the capacitance retention rate remained 90.0% after 10,000 cycles at a scanning speed of 0.1 V s⁻¹. We can see that many mesopores formed by lobular nanorods could provided an effective ion transport paths thereby improving the capacitance and cycle numbers of TiN electrode. Śliwak et al. [78] overcomed the larger particle iron nitride (Fe₂N) blocking the activated carbon (AC) pores in the impregnation method, and prepared a unique FeN₂/AC electrode which can provide an effective ion transport path. So the as synthesized electrode reached an excellent specific capacitance of 507 F g⁻¹ at 0.5 A g⁻¹ and a remarkable rate capability of 72%. Moreover, Ishaq et al. [79] obtained a nanosheet-like quaternary nitride precursor fluorinated graphene (FG)-supported Nickel-Cobalt-Iron nitride nanoparticles on nickel foam (NCF-N@FG/NF) with a large specific surface area by hydrothermal method (Fig. 2 a). The structure and morphology integrity of the hexagonal-plate had been adjusted through varying the NH₃ annealing temperature, and the electrochemical performance can be affected (Fig. 2 b-f). They explained that advantages of those distinctive morphological landscapes were as follows: (i) efficient charge transport, (ii) abundant electrochemical active sites. The as-fabricated asymmetry-device (asy-device) of NCF-N@FG/NF || AC@NF (quaternary nitride precursor fluorinated graphene (FG)-supported Nickel-Cobalt-Iron nitride nanoparticles on nickel foam and activated carbon on Ni foam) was exhibited an outstanding capacitance of 89.5% and an excellen energy density of 56.3 Wh kg⁻¹ at 0.5 A g⁻¹ (Fig. 2 g,h).
水熱法是在封閉的聚四氟乙烯襯里不鏽鋼高壓釜中，在高壓和中溫下合成具有不同形貌和納米結構的TMN電極[76]，由於其單分散顆粒具有可控的尺寸和形態、多功能性和環境友好性，被認為是一種很有前途的製備方法。許多TMN已經通過水熱法制備[2，[77]，[78]，[79]，[80]，[81]]例如，Hou等[2]用水熱法制備了菊花狀TiO ₂ 前驅體，然後對前驅體進行氮化處理，以獲得一種新型的菊花狀氮化鈦（CL-TiN），製備的CL-TiN在1.0 A g ⁻¹ 時的電容為23.35 F g ⁻¹ ， 在0.1 V s ⁻¹ 的掃描速度下，10,000次迴圈后，電容保持率保持在90.0%。我們可以看到，許多由小葉納米棒形成的介孔可以提供有效的離子傳輸路徑，從而提高TiN電極的電容和循環次數。Śliwak等[78]克服了浸漬法中較大顆粒氮化鐵（Fe ₂ N）阻塞活性炭（AC）孔隙的問題，製備了一種獨特的FeN ₂ /AC電極，可提供有效的離子傳輸路徑。因此，合成的電極在0.5 A g ⁻¹ 時達到了507 F g ⁻¹ 的優異比電容和72%的顯著倍率能力。此外，Ishaq等[79]通過水熱法在泡沫鎳（NCF-N@FG/NF）上獲得了納米片狀氟化石墨烯（FG）負載的鎳鈷氮化鐵納米顆粒，比表面積大（圖2a）。 通過改變NH ₃ 退火溫度對六邊形板的結構和形貌完整性進行了調整，電化學性能受到影響（圖2 b-f）。他們解釋說，這些獨特的形態景觀的優點如下：（i）有效的電荷傳輸，（ii）豐富的電化學活性位點。NCF-N@FG/NF的預製非對稱器件（asy-device） ||AC@NF（泡沫鎳上的氮化四元前驅體氟化石墨烯（FG）負載的鎳鈷氮化鐵納米顆粒和泡沫鎳上的活性炭） ⁻¹ 在0.5 A g ⁻¹ 時表現出89.5%的出色電容和56.3 Wh kg的優異能量密度（圖2 g，h）。

1. Download : Download high-res image (2MB)
   下載 ： 下載高解析度影像 （2MB）
2. Download : Download full-size image
   下載：下載全尺寸圖像

Fig. 2. (a) Schematic illustration of the formation mechanism of the NCF-N@FG/NF hybrid, (b,c)TEM images of NCF-L@FG/NF precursor and NCF-N@FG/NF (500 °C) hybrid annealed at 500 °C, (d,e,f) XRD pattern of the NCF-N@FG/NF Hybrid at different annealing temperatures (300, 400 and 500 °C), (g) Specific capacitances of the NCF-N@FG/NF hybrid (300, 400 and 500 °C), (h) Specific capacitance and Coulombic efficiency of NCF-L@FG/NF (500 °C) precursor and NCF-N@FG/NF-3/500 °C hybrid electrode at a current density of 10 A g⁻¹ [79]. Copyright 2018 Elsevier.
圖 2.（a）NCF-N@FG/NF雜化物的形成機理示意圖，（b，c）NCF-L@FG/NF前驅體和NCF-N@FG/NF（500 °C）雜化物在500 °C下退火的TEM圖像，（d，e，f）不同退火溫度（300、400和500 °C）下NCF-N@FG/NF Hybrid的XRD圖譜， （g） NCF-N@FG/NF雜化物的比電容（300， 400和500 °C），（h）NCF-L@FG/NF （500 °C）前驅體和NCF-N@FG/NF-3/500 °C混合電極在電流密度為10 A g ⁻¹ 時的比電容和庫侖效率[79]。版權所有 2018 Elsevier。

The TMN electrodes were prepared by hydrothermal method, on the one hand can improve the compactness of the active substance and the collect without the use of polymer binder without the use of polymer binder, so as to realize effective electricity and transportation; on the other hand, the electrode could be prepared one-dimensional, two-dimensional and three-dimensional with different nanostructures by adjusting temperature and time. Therefore, the hydrothermal process has been considered to be an important way to obtain TMN electrode materials with low cost and high electrochemical performance.
採用水熱法制備TMN電極，一方面可以提高活性物質的緻密性，在不使用聚合物粘結劑的情況下收集不使用聚合物粘結劑，從而實現有效的電力和運輸;另一方面，通過調節溫度和時間，可以製備具有不同納米結構的一維、二維和三維電極。因此，水熱工藝被認為是獲得低成本、高電化學性能的TMN電極材料的重要途徑。

2.2. Magnetro sputtering method
2.2. 磁電機濺射法

Magnetron sputtering is often used to fabricate TMN thin film electrode which exhibited excellent adhesion, controllable composition, thickness and ideal microstructural properties. Researchers have thesized many TMN thin films electrode,VN [[82], [83], [84]], TiN [[85], [86], [87]], MoN [88], WN [89,90], CrN [[91], [92], [93], [94], [95], [96]], HfN [97], NbN [98], GaN [99] VTiN [100,101] etc. TiN thin film electrode has been deposited directly on 304 stainless steel surface by direct current (DC) magnetron sputtering which can be recycled 30,000 times to maintain 92.6% of the initial capacitance at a scanning rate of 5 mV s⁻¹ [86]. Furthermore, Govindarajan et al. [83] reported that the preparation of Cr-doped VN film by reactive magnetron co-deposition, which the RF power for the V target was fixed at 80 W, and the DC power for Cr target was varied from 0 to 14 W. The VN film electrode exhibited highest areal capacitance of 190 mF cm⁻² at 10 mV s⁻¹ and demonstrated the capacitance retention of 92.4% after 5000 cycles in 1 M KOH aqueous electrolyte, when the content of Cr was 5.71 at.%.
磁控濺射通常用於製造TMN薄膜電極，該電極具有優異的附著力、可控的成分、厚度和理想的微觀結構性能。研究人員已經研究了許多TMN薄膜電極，VN [[82]、[83]、[84]]、TiN [[85]、[86]、[87]]、MoN [88]、WN [89,90]、CrN [[91]、[92]、[93]、[94]、[95]、[96]]、HfN [97]、NbN [98]、GaN [99] VTiN [100,101] 等。TiN薄膜電極通過直流（DC）磁控濺射直接沉積在304不鏽鋼表面，可回收30,000次，以5 mV s ⁻¹ 的掃描速率保持92.6%的初始電容[86]。此外，Govindarajan等[83]報導了通過反應磁控共沉積製備Cr摻雜VN薄膜，其中V靶的RF功率固定為80 W，Cr靶的直流功率在0-14 W之間變化。VN薄膜電極在10 mV s ⁻¹ 時表現出最高的面電容，為190 mF cm ⁻² ，在1 M KOH水電解質中迴圈5000次后，當Cr含量為5.71 at.%時，電容保持率為92.4%。

Although many kinds of TMN film electrodes can be prepared by magnetron sputtering, the thin film electrodes deposited by magnetron sputtering are relatively compact, resulting in low capacitance and energy density. In order to improve the electrochemical performance, The CrCuN thin film with roughness (Ra) of 27.23 nm was first prepared by reactive magnetron co-sputtering, and then treated by concentrated nitric acid solution to get porous CrN thin films with Ra of 0.84 nm [94]. The specially treated electrode showed a high area specific capacitance of 31.3 mF cm⁻² in 0.5 M H₂SO₄ electrolyte, Which was superior to that of directly synthesized CrN thin films (Fig. 3a–d). They demonstrated that the abundant porous CrN provided more active sites and decreased the internal resistance [95], and indicated that this simple cost-effective method resulted in excellent electrochemical performance. Moreover, Gao et al. [97] fabricated HfN film electrodes by DC magnetron sputtering, and then etched the film by plasma (Fig. 3e–g). After etching, grooves and holes were left on the surface of film, resulted in increasing the contact sites between electrolyte and thin films electrodes, providing channels for electron transmission, and enhancing the capacitance (41.6 mF cm⁻² at 1.0 mA cm⁻²) of HfN electrode (Fig. 3 h). In order to improve the electrochemical performance of the thin film electrodes, many research groups have used porous materials such as foamed Ni or pre-grown other nanostructured materials on the surface of the substrate, and then coated by magnetron sputtering, so that the specific surface area of the electrode can be increased, thereby increasing the capacitance and energy density of the electrode. Details examples are given in next section.
雖然通過磁控濺射可以製備多種TMN薄膜電極，但磁控濺射沉積的薄膜電極相對緊湊，導致電容和能量密度低。為了提高電化學性能，首先採用反應式磁控共濺射法制備了粗糙度（Ra）為27.23 nm的CrCuN薄膜，然後用濃硝酸溶液處理，得到Ra為0.84 nm的多孔CrN薄膜[94]。經過特殊處理的電極在0.5 M H ₂ SO ₄ 電解液中顯示出31.3 mF cm ⁻² 的高面積比電容，優於直接合成的CrN薄膜（圖3a-d）。他們證明，豐富的多孔CrN提供了更多的活性位點並降低了內阻[95]，並表明這種簡單而具有成本效益的方法產生了優異的電化學性能。此外，Gao等[97]通過直流磁控濺射製備了HfN薄膜電極，然後通過等離子體蝕刻了薄膜（圖3e-g）。蝕刻后，薄膜表面留下凹槽和孔洞，導致電解質和薄膜電極之間的接觸位點增加，為電子傳輸提供通道，並增強了HfN電極的電容（1.0 mA cm時為41.6 mF cm ^{−2 −2} ）（圖3 h）。為了提高薄膜電極的電化學性能，許多研究小組在基板表面使用了多孔材料，如泡沫Ni或預生長的其他納米結構材料，然後通過磁控濺射進行塗層，這樣可以增加電極的比表面積，從而增加電極的電容和能量密度。 下一節將給出詳細範例。

1. Download : Download high-res image (867KB)
   下載 ： 下載高清圖片 （867KB）
2. Download : Download full-size image
   下載：下載全尺寸圖像

Fig. 3. (a) Schematic illustration of the fabrication process for the porous CrN thin films, Top-view SEM images of (b) CrCuN, (c) CrN, (d) Areal specific capacitance of CrCuN and CrN at versus current density [94]. Copyright 2018 Elsevier. (e) The schematic diagrams of the HfN thin films, Surface SEM images of HfN thin films (f) as-deposited HfN thin films, (g) plasma-etched HfN thin films, Areal specific capacitance of plasma etching HfN and as-deposited HfN at versus current density [97]. Copyright 2019 Elsevier.
圖 3.（a）多孔CrN薄膜製備工藝示意圖，（b）CrCuN、（c）CrN、（d）CrCuN和CrN的面比電容與電流密度的關係[94]。版權所有 2018 Elsevier。（e）HfN薄膜的示意圖，HfN薄膜的表面SEM圖像（f）沉積的HfN薄膜，（g）等離子體蝕刻的HfN薄膜，等離子體蝕刻HfN和沉積HfN的面比電容與電流密度的關係[97]。版權所有 2019 Elsevier。

2.3. Template method 2.3. 範本方法

Template technology is a method to prepare synthetic materials by using natural or simple artificial materials as templates, which can make the materials copy and preserve the micro morphology of templates [102]. Generally, materials with graded pore structure can be prepared by hard template or soft template method [103]. Wang et al. [104] prepared titanium TMN/carbon (TiN/C) composite electrode by a green and simple approach that dispersing and calcining the copper drum to uniformly disperse TiN on the carbon template. The TiN/C composite electrode exhibited relatively high specific capacitance of 159.0 F g⁻¹ at 0.5 A g⁻¹, and exceptional rate performance of 96.0 F g⁻¹ at 20 A g⁻¹. Ouldhamadouche et al. [105] reported that nano-tree-like of Vanadium nitride and CNTs nanocomposite (VN/CNTs) electrodes were fabricated by DC sputtering on a vertically aligned carbon nanotubes (CNTs) templates. The VN/CNTs electrodes of nano-structuration provided with network of porous, exhibited specific capacitance of 37.5 mF cm⁻² at the scanning rate of 2 mV s⁻¹, and decreased the cycle life of only 15% after 20,000 cycles. Generally speaking, The structure of nanoarray templates have many advantages, such as large specific surface area, fast electron transport and higher structural stability.
範本技術是一種以天然或簡單的人工材料為範本製備合成材料的方法，可以使材料複製並保留範本的微觀形貌[102]。通常，具有梯度孔結構的材料可以通過硬範本或軟範本方法製備[103]。Wang等[104]通過一種綠色簡單的方法製備了鈦TMN/碳（TiN/C）複合電極，該方法將銅鼓分散和煆燒，使TiN均勻分散在碳範本上。TiN/C複合電極在0.5 A g ⁻¹ 時表現出較高的比電容（159.0 F g ⁻¹ ），在20 A g ⁻¹ 時表現出96.0 F g ⁻¹ 的優異倍率性能。Ouldhamadouche等[105]報導，在垂直排列的碳納米管（CNTs）範本上，通過直流濺射製備了氮化釩和CNTs納米複合材料（VN/CNTs）的納米樹狀電極。納米結構的VN/CNTs電極在2 mV s ⁻¹ 的掃描速率下表現出37.5 mF cm ⁻² 的比電容，在20,000次迴圈后，迴圈壽命僅降低了15%。一般來說，納米陣列範本的結構具有比表面積大、電子傳輸快、結構穩定性高等諸多優點。

In addition, Balamurugan et al. [106] proposed a new strategy to develop core-shell hybrid of NiCo₂N and NiFeN with nitrogen-doped graphene (NG) package. NiCo₂N@NG and NiFeN@NG electrodes with large specific surface area and unique hierarchical architecture were based on NG (as template) (Fig. 4 a,g). The average size and interlayer d-spacing of core-shell NiCo₂N @ NG (≈10–12 nm, 0.249 nm) was slightly larger than the core-shell NiFeN @ NG (8–10 nm, 0.225 nm) (Fig. 4 b-d, h-g) The as-fabricated electrode materials of NiCo₂N@NG and NiFeN@NG electrode retained about 98.16%, 97.69% after 20 000 GCD cycles, which was significantly higher than pristine NiCo₂N (≈56.18%), and pristine NiFeN (≈49.89%), respectively (Fig. 4e and f). Thus the as-prepared flexible asy-device (NiCo₂N@NG || NiFeN@NG) showed an outstanding power density (≈74.67 Wh kg⁻¹ at 39.53 kW kg⁻¹) and an extraordinary energy density (94.93 Wh kg⁻¹ at 0.79 kW kg⁻¹) (Fig. 4 k,l). Therefore, It is an effective way to prepare TMN electrode by template method, because on one hand, carbon materials such as porous carbon, carbon nanotubes and graphene have abundant reserves, low price, and no pollution to the environment; on the other hand, they have good physical and chemical properties, such as strong corrosion resistance and good electrical conductivity and so on.
此外，Balamurugan等[106]提出了一種新策略，以氮摻雜石墨烯（NG）封裝開發NiCo ₂ N和NiFeN的核殼雜化物。具有大比表面積和獨特分層結構的NiCo ₂ N@NG和NiFeN@NG電極基於NG（作為範本）（圖4 a，g）。核殼NiCo ₂ N @ NG （≈10–12 nm， 0.249 nm）的平均尺寸和層間d間距略大於核殼NiFeN @ NG （8–10 nm， 0.225 nm） （圖4 b-d， h-g） NiCo ₂ N@NG和NiFeN@NG電極的製備電極材料在20 000 GCD迴圈後保持率約為98.16%和97.69%，顯著高於原始NiCo ₂ 氮（≈56.18%）和原始鎳鐮化氫（≈49.89%）（圖4e和f）。因此，如製備的柔性 asy-device （NiCo ₂ N@NG ||NiFeN@NG）顯示出出色的功率密度（≈74.67 Wh kg，39.53 ⁻¹ kW kg ⁻¹ ）和非凡的能量密度（94.93 Wh kg，0.79 ⁻¹ kW kg ⁻¹ ）（圖4 k，l）。因此，採用範本法制備TMN電極是一種有效的方法，因為一方面多孔碳、碳納米管、石墨烯等碳材料儲量豐富，價格低廉，對環境無污染;另一方面，它們具有良好的物理和化學性能，如較強的耐腐蝕性和良好的導電性等。

1. Download : Download high-res image (3MB)
   下載 ： 下載高解析度影像 （3MB）
2. Download : Download full-size image
   下載：下載全尺寸圖像

Fig. 4. (a) Schematic illustration of B-NiCo₂N/NG and B-NiFeN/NG hybrids, TEM images and HR-TEM image of (b,c,d) B-NiCo₂N/NG hybrids and (h,i,j) B-NiFeN/NG hybrids, The cycle number of (e) core-shell NiCo₂N@NG and (f) core-shell NiFeN@NG electrodes (inset shows GCD curves: 1st to 10th cycles and 19991st to 20000th cycles). (k) Cycling performance of the five flexible ASC devices, (l) Ragone plot of flexible ASC device in comparison with other recently reported ASCs [106]. Copyright 2018 WILEY-VCH.
圖 4.（a） B-NiCo ₂ N/NG和B-NiFeN/NG雜化物示意圖，（b，c，d）B-NiCo ₂ N/NG雜化物和（h，i，j）B-NiFeN/NG雜化物的TEM圖像和HR-TEM圖像，（e）核殼NiCo ₂ N@NG和（f）核殼NiFeN@NG電極的循環次數（插圖顯示GCD曲線：第1至第10次迴圈和19991至20000次迴圈）。（k）五種柔性ASC器件的迴圈性能，（l）柔性ASC器件與其他最近報導的ASC的Ragone圖[106]。版權所有 2018 WILEY-VCH。

2.4. Electrospining method
2.4. 靜電紡絲法

Electrospinning is a relatively complex but versatile and cost-effective method for preparing mature nanotubes and nanoparticles ranging in the size from a few microns to tens of nanometers [107]. The length and diameter of the nanofibers depend largely on processing parameters, including voltage, liquid flow rate and distance between the tips of the spinneret and receiving equipmen. Impressively, Tan [108] et al. studied the important role of different contents of ammonium molybdate as a precursor in the preparation of C/Mo_xN fibers by electrospinning. The final product of C/Mo_xN fibers with the diameter range of 180–200 nm was annealed in the mixture atmosphere of N₂ and NH₃ at high temperature (Fig. 5a and b,c). They found that the diffusion contribution of 50.8% was slight higher than that capacitance contribution (49.2%) (Fig. 5f and g). They explained the capacitance contribution increased because that ion diffusion speed cannot pull up to redox reaction speed at high scan rate. Three kinds of asy-SCs devices had been assembled with the prepared C/Mo_xN nanofibers, which presented maximum energy density of PANI ||C/Mo_xN asy-SCs of 14.1 Wh kg⁻¹, the power density of 312 W kg⁻¹, which were larger than AC ||C/Mo_xN asy-device (12 Wh kg⁻¹, 325 W kg⁻¹) and C/Mo_xN ||C/Mo_xN symmetry-device (sy-device) (4.51 Wh kg⁻¹, 250 W kg⁻¹) (Fig. 5 h). The asy-device of AC ||C/Mo_xN showed an excellent cycle life along with the specific capacitance of 78.6% after 15,000 cycles at 2 A g⁻¹. Wu et al. [60] reported that the vanadium nitride quantum dot with carbon microporous nanofibers (VN QD/N-doped CNF) was fabricated by combining the electrospinning and nitrogen-doped technologies. when the ratio of NH₃ to N₂ was 3/2 (NH₃: N₂ = 3: 2), the VN QD/N-doped CNF electrode offered a good specific capacitance of 406.5 F g⁻¹ at a current density of 0.5 A g⁻¹ in 6.0 M KOH aqueous solution. Additionally, An et al. [109] prepared furrowed porous structure of carbon fiber networks encapsulated with vanadium nitride (VN/CF) by electrospinning followed by optimail stabilization and carbonization treatments. The fabricated VN/CF hybird electrode showed a specific capacitances of 800 F g⁻¹ at 4 A g⁻¹. The asy-SCs (VN/CF || VN/CF) showed a high energy density of 53.1–36.0 Wh kg⁻¹ at the high power densities in the range 2,700–54,000 W kg⁻¹. All in all, The cross-linked nanofibers of VN/C hybrid electrode consisting of nanoparticles constituted an easy transport paths for charging and electrolyte ions, thus increasing the capacitance and the cycling performance of the electrodes.
靜電紡絲是一種相對複雜但用途廣泛且具有成本效益的方法，用於製備尺寸從幾微米到幾十納米不等的成熟納米管和納米顆粒[107]。納米纖維的長度和直徑很大程度上取決於加工參數，包括電壓、液體流速以及噴絲頭和接收設備尖端之間的距離。Tan[108]等研究了不同含量的鉬酸銨作為前驅體在靜電紡絲製備C/Mo _x N纖維中的重要作用。直徑範圍為180–200 nm的C/Mo _x N纖維的最終產品在N ₂ 和NH的高溫混合氣氛 ₃ 中退火（圖5a和b，c）。他們發現，50.8%的擴散貢獻略高於電容貢獻（49.2%）（圖5f和g）。他們解釋說，電容貢獻增加是因為離子擴散速度在高掃描速率下無法達到氧化還原反應速度。用製備的C/Mo _x N納米纖維組裝了3種asy-SCs器件，呈現出PANI的最大能量密度||C/Mo _x N asy-SCs 為 14.1 Wh kg ⁻¹ ，功率密度為 312 W kg ⁻¹ ，大於 AC ||C/Mo _x N 自動裝置 （12 Wh kg ⁻¹ ， 325 W kg ⁻¹ ） 和 C/Mo _x N ||C/Mo _x N 對稱裝置 （sy-device） （4.51 Wh kg ⁻¹ ， 250 W kg ⁻¹ ） （圖 5 h）。AC 的 asy-device ||C/Mo _x N在2 A g ⁻¹ 下迴圈15,000次后顯示出優異的循環壽命和78.6%的比電容。Wu et al. [60]報導了結合靜電紡絲和氮摻雜技術製備了具有碳微孔納米纖維的氮化釩量子點（VN QD/N摻雜CNF）。當 ₃ NH與N ₂ 的比值為3/2（NH ₃ ：N ₂ =3：2）時，VN QD/N摻雜CNF電極在6.0 M KOH水溶液中，在0.5 A g ⁻¹ 的電流密度下提供了406.5 F g ⁻¹ 的良好比電容。此外，An等[109]通過靜電紡絲製備了氮化釩（VN/CF）封裝的碳纖維網路的溝槽多孔結構，然後進行optimail穩定化和碳化處理。製備的VN/CF hybird電極在4 A g ⁻¹ 時的比電容為800 F g ⁻¹ 。asy-SC （VN/CF ||VN/CF） ⁻¹ 在2,700-54,000 W kg的高功率密度範圍內顯示出53.1-36.0 Wh kg的高能量密度 ⁻¹ 。綜上所述，由納米顆粒組成的VN/C雜化電極交聯納米纖維構成了充電離子和電解質離子的便捷運輸路徑，從而提高了電極的電容和迴圈性能。

1. Download : Download high-res image (2MB)
   下載 ： 下載高解析度影像 （2MB）
2. Download : Download full-size image
   下載：下載全尺寸圖像

Fig. 5. (a) Illustration of synthesis process, The C/Mo_xN images of (b, c) SEM, (d) TEM and (e) the elements mapping, (g) Capacitive contribution and diffusion contribution at 0.005 V s⁻¹, (h) Normalized contribution ratio of capacitive capacities at different scan rates, cycle life of C/Mo_xN ||C/Mo_xN device at 2 A g⁻¹ (inset: cycle life of PANI ||C/Mo_xN device at 2 A g⁻¹) [108]. Copyright 2018 Elsevier.
圖 5.（a） 合成過程圖示，（b，c） SEM，（d） TEM 和 （e） 元素映射的 C/Mo _x N 圖像，（g） 0.005 V s ⁻¹ 時的電容貢獻和擴散貢獻，（h） 不同掃描速率下電容容量的歸一化貢獻比，C/Mo _x N 的循環壽命 ||2 A g ⁻¹ 的 C/Mo _x N 器件（插圖：PANI 的循環壽命 ||2 A g ⁻¹ 的 C/Mo _x N 器件 [108]。版權所有 2018 Elsevier。

The hybrid electrode with core-shell structure can also be obtained by coaxial electrospinning, The key to the operation is to ensure that the inner core and shell solution can form a concentric composite jet [110]. Zhou et al. [111] synthesized mesoporous TiN/VN fibers with core-shell structure by coaxial electrospinning and subsequent NH₃ annealing. The inner diameter and outer diameter of mesoporous fibers were about 300 nm and 660 nm, respectively. The core-shell TiN/VN fiber can introduce the mesoporous structure into the high conductivity transition nitriding hybrid, which combined the higher specific capacitance of VN and the better rate performance of TiN. The surface area of TiN/VN fibers was 169 m² g⁻¹ and the average pore size was about 3 nm by measuring the porosity of TiN-VN fibers by nitrogen adsorption. They elucidated that these hybrid models presented a higher specific capacitance (2 mV s⁻¹, 247.5 F g⁻¹) and better rate capability (50 mV s⁻¹, 160.8 F g⁻¹). Therefore, the combination of VN and TiN into high efficient and fast mixed nanocomposites can be expected to provide electrochemical storage materials in the future.
具有核殼結構的混合電極也可以通過同軸靜電紡絲獲得，其操作的關鍵是保證內核殼溶液能夠形成同心複合射流[110]。周等[111]通過同軸靜電紡絲和隨後的NH ₃ 退火合成了具有核殼結構的介孔TiN/VN纖維。介孔纖維的內徑和外徑分別約為300 nm和660 nm。核殼TiN/VN光纖可以將介孔結構引入高導電性轉變氮化雜化物中，結合了VN較高的比電容和TiN較好的倍率性能。通過氮氣吸附測量TiN-VN纖維的孔隙率，TiN/VN纖維的表面積為169 m ² g ⁻¹ ，平均孔徑約為3 nm。他們闡明瞭這些混合模型具有更高的比電容（2 mV s，247.5 ⁻¹ F g ⁻¹ ）和更好的倍率能力（50 mV s，160.8 ⁻¹ F g ⁻¹ ）。因此，VN和TiN結合成高效快速的混合納米複合材料有望在未來提供電化學存儲材料。

2.5. Electrodeposition method

Electrodeposition is a common method to prepare nano materials. The thickness of the film can be controlled by the deposition current and time. At the same time, the film with different morphology and structure can be prepared by selecting the appropriate deposition solution. According to the principle of electrodeposition, it can be divided into anode electrodeposition and cathode electrodeposition. For example, Xie et al. [112] prepared TiN nanoarrays with short nanotubes and long nanoporous structures whose aspect ratio respectively was 7.0 and 117.8 by anodizing and nitriding Ti foil. They found that the capacitance of TiN in acidic electrolytes was superior to that in alkaline and neutral electrolytes by CV and EIS measurements. The capacitance of TiN nanoarrays reached a very high level of 99.7 mF cm⁻² at 0.2 mA cm⁻² and increased by 8.5 times with the increase of the aspect ratio of nanotubes increased from 7.0 nm to 117.8 nm, which was the most significant improvement for TiN nanotube arrays.
電沉積是製備納米材料的常用方法。薄膜的厚度可以通過沉積電流和時間來控制。同時，通過選擇合適的沉積溶液，可以製備不同形貌和結構的薄膜。按電沉積原理可分為陽極電沉積和陰極電沉積。例如，Xie等[112]通過陽極氧化和氮化Ti箔製備了具有短納米管和長納米多孔結構的TiN納米陣列，其長寬比分別為7.0和117.8。他們發現，通過CV和EIS測量，酸性電解質中TiN的電容優於鹼性和中性電解質的電容。在0.2 mA cm ⁻² 時，TiN納米陣列的電容達到了99.7 mF cm ⁻² 的非常高的水準，隨著納米管長徑比的增加，TiN納米管的電容從7.0 nm增加到117.8 nm，電容增加了8.5倍，這是TiN納米管陣列最顯著的改進。

Anodized or micro-arc oxidation were used to grow an oxide film on the substrate, and high-temperature ammonia annealing is performed to obtain a nitride nanotube, which can be used as a matrix of pseudocapacitance material. The electrode with this structure not only increases the specific surface area, but also increases the quality of active sites, the capacitance, energy density and cycle life of the electrode. For example, MoN_x energy storage was achieved by reversible proton intercalation/delamination and reversible adsorption/desorption of active ions in aqueous electrolyte solutions [113,114]. Larger surface area of 3D titanium nitride nanotube arrays (TiN NTA) tubular channels was conducive to the ion diffusion and electronic transport capabilities of active materials [[114], [115], [116]]. Xie et al. [117] deposited molybdenum nitride (MoN_x) in titanium oxide nanotubes (TiO₂ NTA) with vertically oriented and highly ordered nanotube structure (Fig. 6b and c), and then NH₃ annealed to prepare molybdenum nitride/titanium nitride nanotube arrays electrode (MoN_x/TiN-NTA) which still kept an open porous structure (Fig. 6d and e). They explained that the introduction of MoN_x onto TiN NTA can enhance the electron transport capacitance of MoN_x/TiN-NTA electrode, and the total electrochemical impedance decreases from 15.75 Ω (TiN NTA) to 7.25 Ω (MoNx/TiN NTA). The MoN_x/TiN-NTA electrode exhibited a significantly higher capacitance (121 mF cm⁻²) than that of TiN-NTA (69.05 mF cm⁻²) and displayed the capacitance of MoN_x/TiN-NTA retention of 93.8% after 1000 cycles at 3.0 mA cm⁻² (Fig. 6f and g).
採用陽極氧化或微弧氧化在基板上生長氧化膜，並進行高溫氨退火得到氮化物納米管，可用作贗電容材料的基體。具有這種結構的電極不僅增加了比表面積，而且還提高了活性位點的品質、電容、能量密度和電極的循環壽命。例如，MoN _x 儲能是通過可逆質子插層/分層和活性離子在電解質水溶液中的可逆吸附/解吸來實現的[113,114]。氮化鈦納米管陣列（TiN NTA）管狀通道的比表面積較大，有利於活性材料的離子擴散和電子傳輸能力[[114]，[115]，[116]]。Xie等[117]將氮化鉬（MoN _x ）沉積在氧化鈦納米管（TiO ₂ NTA）中，具有垂直取向和高度有序的納米管結構（圖6b和c），然後NH ₃ 退火製備氮化鈦/氮化鈦納米管陣列電極（MoN _x /TiN-NTA），該電極仍保持開放的多孔結構（圖6d和e）。他們解釋說，在TiN NTA上引入MoN _x 可以增強MoN _x /TiN-NTA電極的電子傳輸電容，總電化學阻抗從15.75 Ω（TiN NTA）降低到7.25 Ω（MoNx/TiN NTA）。MoN _x /TiN-NTA電極的電容（121 mF cm ⁻² ）明顯高於TiN-NTA（69.05 mF cm ⁻² ），在3.0 mA cm ⁻² 下迴圈1000次后，MoN _x /TiN-NTA的電容保留率為93.8%（圖6f和g）。

1. Download : Download high-res image (1022KB)
   下載：下載高解析度圖片（1022KB）
2. Download : Download full-size image
   下載：下載全尺寸圖像

Fig. 6. (a) The schematic showing the fabrication process of MoN_x/TiN NTA, Top-view and cross-section view SEM images of (b,c) TiN NTA and (d,e) MoN_x/TiN NTA, (f) Cycling GCD curves, (h) Capacitance decay curve of MoN_x/TiN NTA [117]. Copyright 2016 Elsevier.
圖 6.（a）MoN _x /TiN NTA製備工藝示意圖，（b，c）TiN NTA和（d，e）MoN _x /TiN NTA的俯視圖和截面圖SEM圖像，（f）迴圈GCD曲線，（h）MoN _x /TiN NTA的電容衰減曲線[117]。版權所有 2016 Elsevier。

Electrodeposition method is widely used in the preparation of TMN electrode materials because of its deposited uniformly on a variety of complex substrates; electrochemical deposition is also usually carried out at room temperature or slightly above room temperature, making it ideal for the preparation of nanostructured electrodes for precise film thickness control.
電沉積法因其均勻地沉積在各種複雜基板上而廣泛用於TMN電極材料的製備;電化學沉積通常也在室溫或略高於室溫下進行，因此非常適合製備納米結構電極，以實現精確的薄膜厚度控制。

2.6. Other method 2.6. 其他方法

In addition to the five common preparation methods described above, TMN have other preparation methods. Compared with the stacked graphene layers synthesized by solution synthesis, the graphene nanosheets (GNS) vertically arranged on current collectors has much more surface area. The increase in surface area will lead to excellent performance because the device relies strongly on the available active surface sites for charge absorption and redox reactions. For example, Li et al. [118] proposed a 0D-in-2D pillared lamellar material comprising VN nanodots intercalated carbon nanosheets (VNNDs/CNSs) was synthesized by a novel spatially-confined strategy. As-fabricated VNNDs/CNSs presented a volume capacitance of 1203.6 F cm⁻³ at 1.1 A cm⁻³, and the rate capacitance of 703.1 F cm⁻³ at a high current density of 210 A cm⁻³. The author emphasised that 2D carbon nanosheets can prevented VN nanodots from aggregating, reduced the electrochemical dissolution of VNNDs and improved the large capacitance and stability (Fig. 7a–e). Li et al. [119] reported that the hexagonal boron nitride/carbon nanocomposite electrode (h-BN/C) was prepared by simple annealing route due to pristine h-BN with inherent low conductivity and large band gap in the application of electrochemical energy storage conversion system. The capacitance was as high as 250 F g⁻¹ at the current density of 0.5 A g⁻¹ More importantly, the water-based asy-SCs h-BN/C || AC can provide working voltage of 1.45 V and energy density of 17 Wh kg⁻¹ when the power density was 245 W kg⁻¹. Therefore, the inexpensive h-BN/C nanocomposites have a broad application prospects in the field of water-borne asym-SCs in electrochemical energy storage and conversion systems (Fig. 7f and g). Moreover, Liu et al. [120] reported an in-situ preparation strategy based on ammonification process of ionic amphiphilic triblock copolymer micelles/vanadium-contained ions system in NH₃/N₂ atmosphere was used to synthesize vanadium nitride nanoparticles on porous carbon nanospheres (PCNs@VNNP). The authors elucidated that the prepared PCNs@VNNP material presented a high specific capacitance of 229.7 F g⁻¹, and the capacitance decay rate was only 27.2% after 1000 cycles. They explained the increase of cycle numbers was mainly due to the size of VN quantum dots and the support of porous carbon, for purpose of significantly improving the utilization of active materials without affecting their conductivity (Fig. 7h–j).
除了上述五種常見的製備方法外，TMN還有其他製備方法。與溶液合成合成的堆疊石墨烯層相比，垂直排列在集流體上的石墨烯納米片（GNS）具有更大的表面積。表面積的增加將帶來出色的性能，因為該器件強烈依賴於電荷吸收和氧化還原反應的可用活性表面位點。例如，Li等[118]提出了一種由VN納米點嵌入碳納米片（VNNDs/CNSs）組成的0D-in-2D柱狀層狀材料，該材料採用一種新的空間限制策略合成。在1.1 A cm時，VNNDs/CNS的體積電容為1203.6 F cm ⁻³ ，在210 A cm ^{−3 −3} 的高電流密度下，速率電容為703.1 F cm ⁻³ 。作者強調，二維碳納米片可以防止VN納米點聚集，減少VNND的電化學溶解，提高大電容和穩定性（圖7a-e）。Li等[119]報導了六方氮化硼/碳納米複合電極（h-BN/C）是採用簡單退火路線製備的，因為h-BN具有固有的低電導率和大帶隙，在電化學儲能轉換系統中的應用。在0.5 A g ⁻¹ 的電流密度下，電容高達250 F g ⁻¹ 更重要的是，水基 asy-SCs h-BN/C || ⁻¹ 當功率密度為 1.45 W kg 時，AC 可以提供 17 V 的工作電壓和 245 Wh kg 的能量密度 ⁻¹ 。 因此，廉價的h-BN/C納米複合材料在電化學儲能和轉換系統中的水性非對稱SC領域具有廣闊的應用前景（圖7f和g）。此外，Liu等[120]報導了一種基於離子兩親性三嵌段共聚物膠束/含釩離子體系在NH ₃ /N ₂ 氣氛中的氨化過程的原位製備策略，用於在多孔碳納米球上合成氮化釩納米顆粒（PCNs@VNNP）。作者闡明瞭所製備的PCNs@VNNP材料呈現出229.7 F g ⁻¹ 的高比電容，1000次迴圈後電容衰減率僅為27.2%。他們解釋說，迴圈次數的增加主要是由於VN量子點的大小和多孔碳的支撐，目的是在不影響其電導率的情況下顯著提高活性材料的利用率（圖7h-j）。

1. Download : Download high-res image (3MB)
   下載 ： 下載高解析度影像 （3MB）
2. Download : Download full-size image
   下載：下載全尺寸圖像

Fig. 7. (a) Schematic illustration of the preparation procedures of the VNNDs/CNSs, SEM images of (b) V₂O₅ 1.6H₂O, (c) PANI intercalated V₂O₅ nanosheets, and (d) VNNDs/CNSs, (e) Stability of the device (The inset shows the CV curves of the solid-state SC before and after 10,000 cycles) [118]. Copyright 2018 Elsevier. (f) Electrochemical behaviors of the fabricated ASCs based on h-BN/C in the two-electrode testing device, (g) Ragone plots of the ASC based on h-BN/C nanocomposite as cathode (The inset is a demonstration of application in the LED indicator) [119]. Copyright 2019 Elsevier. Schematic illustration of VN-carbon composite design by (h) In-situ preparation approach, (i) mapping images for PCNS@VNNP, (j) Cycle stability for 10000 cycles at a current density of 10 A g⁻¹ [120]. Copyright 2016 Elsevier. (k) Schematics of the fabrication processes of TMN cathode and anode materials, SEM images of (l) TiN@GNS, and (m) FeOOH@GNS, (n) Cycling performance of five parallel devices within 20 000 cycles (Inset figure shows the percentages of capacity retention) [121]. Copyright 2015 WILEY-VCH.
圖 7.（a）VNNDs/CNSs製備程式示意圖，（b）V ₂ O ₅ 1.6H ₂ O，（c）PANI嵌入V ₂ O ₅ 納米片和（d）VNNDs/CNSs的SEM圖像，（e）器件的穩定性（插圖顯示了10,000次迴圈前後固態SC的CV曲線）[118]。版權所有 2018 Elsevier。（f）雙電極測試裝置中基於h-BN/C的ASC的電化學行為，（g）基於h-BN/C納米複合材料作為陰極的ASC的Ragone圖（插圖是LED指示器中的應用演示）[119]。版權所有 2019 Elsevier。（h）原位製備方法，（i）PCNS@VNNP映射圖像，（j）電流密度為10 A g ⁻¹ 時10000次迴圈的循環穩定性[120]。版權所有 2016 Elsevier。（k）TMN正極和負極材料的製造工藝示意圖，（l）TiN@GNS和（m）FeOOH@GNS的SEM圖像，（n）20 000次迴圈內五個並聯器件的迴圈性能（插圖顯示了容量保持百分比）[121]。版權所有 2015 WILEY-VCH。

Zhu et al. [121] synthetized two kinds of TMN, titanium nitride (TiN) with porous layer (Fig. 7 d) and ferrous nitride (Fe₂N) with nanoparticles on vertically arranged graphene nanosheets by atomic layer deposition (ALD), respectively. The Solid-state asy-SCs with excellent electrochemical activity (TiN/Fe₂N were used as cathode/anode) showed an capacitance retention of 98% after 2000 cycles in PVA/LiCl neutral electrolyte. The outstanding cycling stability due to the porous structure of TiN and uniform coverage of Fe₂N nanoparticles on the GNS substrates (Fig. 7k–n).
Zhu等[121]通過原子層沉積（ALD）在垂直排列的石墨烯納米片上分別合成了兩種TMN，即具有多孔層的氮化鈦（TiN）（圖7 d）和具有納米顆粒的氮化亞鐵（Fe ₂ N）。電化學活性優異的固態ASY-SCs（TiN/Fe ₂ N作為陰極/陽極）在PVA/LiCl中性電解質中迴圈2000次后電容保持率為98%。由於TiN的多孔結構和Fe ₂ N納米顆粒在GNS襯底上的均勻覆蓋，具有出色的迴圈穩定性（圖7k-n）。

In order to prepare TMN electrode with more excellent electrochemical performance, many research groups try to use a variety of methods to prepare TMN electrode with large specific surface area, large specific volume and excellent cycle performance. However, it brings the disadvantage of larger contact resistance, poorer conductivity and lower voltage window.
為了製備具有更優異電化學性能的TMN電極，許多研究課題組嘗試採用多種方法製備比表面積大、比體積大、迴圈性能優異的TMN電極。但是，它帶來了接觸電阻較大、導電性較差和電壓視窗較低等缺點。

2.7. Summary of preparation methods
2.7. 製備方法總結

In summary, the five methods proposed above are the basic methods for preparing TMN electrodes, including hydrothermal methods, magnetron sputtering, template methods, electrospinning methods, and electrochemical deposition methods. Each method has its own advantages and disadvantages. The hydrothermal method was the most commonly used, because it can be prepared TMN eletrode with different morphologies according to the concentration of solution and heating time, However, the film thickness obtained by hydrothermal method is not uniform and its application in some precision fields is limited. By comparison, the magnetron sputtering method is mostly used for thin film electrodes, the thickness of prepared film is uniform and also used be on chips. but the disadvantage is that the capacitance is low due to compactness. While Both electrospinning/Electrodeposition can fabricated TMN elctrode with specific morphology by adjusting the parameters of the current. The template method can be obtained highly ordered structure electrode with special shapes. At present, most of TMN electrodes are prepared by hydrothermal method or electrodeposition method, and then the tantalum capacitor material is deposited by ALD, DC magnetron sputtering or other method to further improve the electrochemical properties of the TMN electrode.
綜上所述，上述五種方法是製備TMN電極的基本方法，包括水熱法、磁控濺射法、範本法、靜電紡絲法和電化學沉積法。每種方法都有自己的優點和缺點。水熱法是最常用的，因為它可以根據溶液的濃度和加熱時間製備不同形貌的TMNeletrode，但水熱法得到的膜厚並不均勻，在一些精密領域的應用有限。相比之下，磁控濺射法多用於薄膜電極，製備的薄膜厚度均勻，也用於晶元上。但缺點是由於緊湊性，電容低。而靜電紡絲/電沉積都可以通過調整電流參數來製造具有特定形貌的TMN elctrode。範本法可得到具有特殊形狀的高度有序結構電極。目前，TMN電極大多採用水熱法或電沉積法制備，然後採用ALD、直流磁控濺射等方法沉積鉚電容器材料，進一步提高TMN電極的電化學性能。

3.1. Binary TMN 3.1. 二進位TMN

3.1.1. VN 3.1.1. 越南

Among numerous TMN systems, vanadium nitride have been used as electrode materials for SCs, with excellent mechanical properties, notable electrical conductivity (σbulk = 1.67 × 10⁶ Ω⁻¹ m⁻¹), corrosion resistance, high theoretical capacitance, good chemical stability, and fast Faraday redox reaction [101,[104], [105], [106], [107], [108], [109]]. It is reported that the impressive specific capacitance of VN electrode was up to high 1340 F g⁻¹ at the scan rate of 2 mV s⁻¹ in 1 M KOH aqueous electrolyte [146]. VN electrode could be synthesized by simple physical or chemical methods [82,84,141,142,[147], [148], [149], [[150], [151]] to obtain the electrode with different morphologies, such as nanolobes [141], nanopowders [151], nanopillars [82], nanowires [122] etc. (Fig. 8a and b,c,d). For example, A mesoporous vanadium nitride (mesoporous VN) electrode was synthesized directly from vanadium tetrachloride and urea by one-step chemical precipitation at low temperature (70 °C) [141], and showed the prepared mesoporous VN consisted of long and fine nanowhiskers, whose diameters were 5–20 nm, lengths were 50–300, and mesoporous diameters were 2–5 nm (Fig. 8 a). The authors elucidated that mesoporous VN electrode exhibited an excellent specific capacitance of 598 F g⁻¹ at a current density of 4 A g⁻¹, along with maintained the initial capacitance of 83% after 5000 cycles. Zhou et al. [147] reported that vanadium nitride powders (VN powders) with an average grain size of 200 nm were synthesized under NH₃ annealing at 400 °C, whose capacitance was 161 F g⁻¹ at 30 mV s⁻¹ (Fig. 8 b). However, Lucio-Porto et al. [82] were prepared VN thin film electrode by DC reactive magnetron sputtering. The film electrode displayed a maximum specific capacitance of 422 F g⁻¹ in 1 M KOH aqueous, with the thickness below 100 nm reached the volumetric power of 125 W cm⁻³. Robert [84] et al. obtained different cross section morphologies of VN thin films (Fig. 8e and f,g) by fine-tuning sputtering deposition parameters (temperature, pressure, and films thickness). They explained that the diffusion process (temperature) and atomic peening (pressure) effects have proved to be the core phenomena to adjust the inter- and intraporosities within the columnar morphology of the thin film. While film densification was obviously efficient to increase the electrical conductivity. With the increase of deposition temperature and thickness, the conductivity of the film increases first and then decreases, and decreases with the increase of deposition pressure. (Fig. 8h and i,j). The results showed that the films capacitance increases from 28 to 45 mF cm⁻² and the volume capacitance of 1350 F cm⁻³, which was 4.2 times larger than that of TiC₂ and Mxene in alkaline medium.
在眾多TMN體系中，氮化釩已被用作SC的電極材料，具有優異的機械性能、顯著的導電性（σbulk = 1.67 × 10 ⁶ Ω ⁻¹ m ⁻¹ ）、耐腐蝕性、高理論電容、良好的化學穩定性和快速的法拉第氧化還原反應[101，[104]，[105]，[106]，[107]，[108]，[109]]。據報導，在1 M KOH水性電解質中，在2 mV s ⁻¹ 的掃描速率下，VN電極的比電容高達1340 F g ⁻¹ [146]。VN電極可以通過簡單的物理或化學方法[82,84,141,142，[147]，[148]，[149]，[[150]，[151]]合成具有不同形貌的電極，如納米瓣[141]，納米粉末[151]，納米柱[82]，納米線[122]等（圖8a和b，c，d）。例如，在低溫（70 °C）下通過一步化學沉澱直接從四氯化釩和尿素合成了介孔氮化釩（介孔VN）電極[141]，並表明製備的介孔VN由長而細的納米晶須組成，其直徑為5-20 nm，長度為50-300，介孔直徑為2-5 nm（圖8 a）。作者闡明，介孔VN電極在4 A g ⁻¹ 的電流密度下表現出598 F g ⁻¹ 的優異比電容，同時在5000次迴圈后保持了83%的初始電容。周等[147]報導，在400 °C的NH ₃ 退火下合成了平均晶粒尺寸為200 nm的氮化釩粉末（VN粉末），其電容在30 mV s時為161 F g ^{−1 −1} （圖8 b）。然而，Lucio-Porto等[82]通過直流反應磁控濺射製備了VN薄膜電極。 薄膜電極在1 M KOH水溶液中的最大比電容為422 F g ⁻¹ ，厚度低於100 nm時，體積功率達到125 W cm ⁻³ 。Robert[84]等人通過微調濺射沉積參數（溫度、壓力和薄膜厚度）獲得了VN薄膜的不同截面形貌（圖8e和f，g）。他們解釋說，擴散過程（溫度）和原子噴丸（壓力）效應已被證明是調整薄膜柱狀形態內孔隙間和孔隙內的核心現象。而薄膜緻密化顯然可以有效地提高導電性。隨著沉積溫度和厚度的增加，薄膜的電導率先增大后降低，並隨著沉積壓力的增加而降低。（圖 8h 和 i，j）。結果表明，薄膜電容從28 mF cm增加到45 mF cm ⁻² ，體積電容為1350 F cm ⁻³ ，是TiC ₂ 和Mxene在鹼性介質中的4.2倍。

1. Download : Download high-res image (2MB)
   下載 ： 下載高解析度影像 （2MB）
2. Download : Download full-size image
   下載：下載全尺寸圖像

Fig. 8. The different morphologies of VN (a) nanolobes [141], Copyright 2017 Elsevier. (b) nanopowder [151], Copyright 2009 Elsevier. (c) nanocolumns [82], Copyright 2014 Elsevier. (d) nanowires [122]. Copyright 2013 American Chemical Society. SEM cross section analysis of the VN thin films at different (e) temperature, (r) pressure and (g) thicknesses [82], Evolution of electrical conductivity, thin film density, and surface roughness (inset) as a function of (h) temperature, (i) pressure and (j) thicknesses [82]. Copyright 2018 Wiley-VCH. (k) Cyclic voltammograms of the various VN materials, (l,m) The capacitance and Nyquist plots of ammonolysis. derived VN electrodes of different loadings [150]. Copyright 2018 Elsevier.
圖 8.VN （a） 納米瓣的不同形態 [141]，版權所有 2017 Elsevier。（b） 納米粉末 [151]，版權所有 2009 Elsevier。（c） 納米色譜柱 [82]，版權所有 2014 Elsevier。（d）納米線[122]。版權所有 2013 美國化學學會。VN薄膜在不同（e）溫度、（r）壓力和（g）厚度下的SEM橫截面分析[82]，電導率、薄膜密度和表面粗糙度（插圖）隨（h）溫度、（i）壓力和（j）厚度的變化[82]。版權所有 2018 Wiley-VCH。（k）各種VN材料的迴圈伏安圖，（l，m）氨溶解的電容圖和奈奎斯特圖。衍生出不同負載的VN電極[150]。版權所有 2018 Elsevier。

The electrochemical performance of the VN thin films had a close relationship with the thickness of the thin films [82], which was mainly attributed to the accumulation of space charge on the surface of the VN film. In the case of an effective charge accumulation thickness reached 100 nm, there existed an active subsurface layer in which the charge shielding length was approximately 30 nm. Lucio-Porto [126] found that the films thickness of 60 nm was extreme critical, below the thickness, the film was insufficient to promote electron transfer [82]. However several studies have suggested that the high capacitance of the VN electrode was caused by the Faraday redox reaction occurring on the surface of the nitrides [129]. However, Hanumantha [150] and others believed that the cyclic stability of VN depends on the size of particles that may be different in the surface oxidation state. A vanadium nitride (VN) electrode with crystallite size of 4.1 nm was ynthesized by two-step ammonlysis method. They found that the faradaic redox reaction took place more obviously on the VN prepared by ammonlysis with the smallest crystallite size and the larger surface area in that the higher specific surface area resulted in increasing contact sites with the surface oxide of the electrolyte. Hence, TMN capacitance is directly proportional to surface area (Fig. 8 k). They also elucidated that the capacitance of an electrode to store charges was limited by the electrode loading (Fig. 8l and m). We can see that with the increase of mass loading, the transfer resistance increased, possibly because the thicker electrode can not provide the capacitance to easily access to ions but can travel to the surface sites through fine nanoparticles. Thus, the capacitance of VN electrode was inversely proportional to particle size. In addition, many groups have deeply analyzed the mechanism of charge storage in VN electrodes. Previously, Pande et al. [138] used ion isolation experiments in aqueous electrolytes to prove that hydroxide (OH⁻) was the reactive ion can produced the pseudocapacitance. The in-situ small-angle neutron scattering (SANS) and in-situ X-ray absorption spectroscopy (XAS) combined with physical and electrochemical characterization techniques were used to analyze the pseudocapacitance charge storage mechanism of VN materials in alkaline aqueous solution [151]:(5)${{\text{V}}^{3+}\text{N}+{2\text{OH}}^{-}+{\text{e}}^{-}\leftrightarrow {\text{V}}^{2+}\text{N}\left({\text{OH}}^{-}\right)}_2$
VN薄膜的電化學性能與薄膜的厚度密切相關[82]，這主要歸因於VN薄膜表面空間電荷的積累。在有效電荷積累厚度達到100 nm的情況下，存在一個活躍的地下層，其中電荷遮罩長度約為30 nm。Lucio-Porto[126]發現，60 nm的薄膜厚度極為臨界，低於厚度，薄膜不足以促進電子轉移[82]。然而，一些研究表明，VN電極的高電容是由氮化物表面發生的法拉第氧化還原反應引起的[129]。然而，Hanumantha[150]等人認為，VN的迴圈穩定性取決於表面氧化態可能不同的顆粒的大小。採用兩步鉸解法對微晶尺寸為4.1 nm的氮化釩（VN）電極進行氮化釩（VN）電極的合成。他們發現，法拉第氧化還原反應更明顯地發生在通過氨解製備的VN上，微晶尺寸最小，表面積較大，因為較高的比表面積導致與電解質表面氧化物的接觸位點增加。因此，TMN電容與表面積成正比（圖8 k）。他們還闡明，電極存儲電荷的電容受電極負載的限制（圖8l和m）。我們可以看到，隨著品質負載的增加，轉移電阻增加，可能是因為較厚的電極不能提供容易接近離子的電容，而是可以通過細小的納米顆粒傳播到表面部位。 因此，VN電極的電容與粒徑成反比。此外，許多課題組深入分析了VN電極中電荷存儲的機理。此前，Pande等[138]利用水電解質中的離子分離實驗證明瞭氫氧化物（OH ⁻ ）是反應性離子可以產生的贗電容。採用原位小角中子散射（SANS）和原位X射線吸收光譜（XAS）結合物理和電化學表徵技術，分析了VN材料在鹼性水溶液中的贗電容電荷存儲機理[151]： (5)${{\text{V}}^{3+}\text{N}+{2\text{OH}}^{-}+{\text{e}}^{-}\leftrightarrow {\text{V}}^{2+}\text{N}\left({\text{OH}}^{-}\right)}_2$

Djire and Pande et al. [151] found that the pseudocapacitance charge storage mechanism of VN was through the insertion/extraction of anions inside and outside the micropores (i.e. OH⁻ or OD⁻). These findings were similar to those reported in carbon materials, where maximum charge storage was achieved in small pores, especially within the size of ionic size range [[152], [153], [154], [155], [156], [157], [158], [159], [160], [161], [162], [163]]. Through these examples, we can know that the mechanism of charge storage in VN electrodes is not only related to the oxidation state and the size of voids on the surface of VN electrodes, but also to the thickness of active substances.
Djire和Pande等[151]發現，VN的贗電容電荷存儲機制是通過插入/提取微孔內外的陰離子（即 ⁻ OH或OD ⁻ ）。這些發現與碳材料中報導的相似，在碳材料中，在小孔中實現了最大的電荷存儲，特別是在離子尺寸範圍[[152]，[153]，[154]，[155]，[156]，[157]，[158]，[159]，[160]，[161]，[162]，[163]]。通過這些例子，我們可以知道，VN電極中電荷存儲的機理不僅與氧化態和VN電極表面空隙的大小有關，還與活性物質的厚度有關。

Sy-SCs and asy-SCs were fabricated based on the remarkable capacitance value of vanadium nitride electrode. Robert et al. [84] proposed the vanadium nitride/vanadium nitride (VN || VN) symmetrical Micro-supercapacitors (sy-MSCs) prepared with VN films, and found that the VN film with a thickness of 2 μm presented the energy density of 2 μWh cm⁻³achieved higher than the hybrid MSCs Graphene- or graphene/carbon nanotubes (G || CNT) [130], G ||G [164], graphene oxide/CNT (γ-GO || CNT [165]) and Nickel oxide/VN (NiO || VN) [142] hybrid microdevice. Moreover, Lu [129] reported the Vanadium oxide/Vanadium nitride (VO_x || VN) asy-SCs device achieved a significant volumetric energy density of 0.61 mWh cm⁻³ at a current density of 0.5 mA cm⁻², which was higher 7 times than that of the VN || VN Sy-SCs device (0.079 mWh cm⁻³). It was worth noting that the volumetric energy density of VOx || VN asy-SCs was also much higher than that of quasi/all solid state SCs [[166], [167], [168], [169], [170], [171], [172]], such as G-based SCs (0.06 mWh cm⁻³, PVA/H₃PO₄) [167], SCs of MnO₂ carbon particles (CNPs) (0.09 mWh cm⁻³, 0.5 mA cm⁻², PVA/H₃PO₄) [168] and TiN-based SCs (0.045 mWh cm⁻³, PVA/KOH) [170] and so on.
基於氮化釩電極顯著的電容值，製備了Sy-SCs和asy-SCs。Robert等[84]提出了氮化釩/氮化釩（VN ||VN）用VN薄膜製備的對稱微型超級電容器（sy-MSCs），發現厚度為2 μm的VN薄膜呈現出比 ⁻³ 混合MSCs石墨烯或石墨烯/碳納米管（G ||碳納米管）[130]，G ||G [164]，氧化石墨烯/碳納米管（γ-GO ||碳納米管 [165]） 和氧化鎳/VN （NiO ||VN） [142] 混合微器件。此外，Lu [129]報導了氧化釩/氮化釩（VO _x ||VN）asy-SCs器件在0.5 mA cm ⁻² 的電流密度下實現了0.61 mWh cm ⁻³ 的顯著體積能量密度，比VN高7倍||VN Sy-SCs 設備 （0.079 mWh cm ⁻³ ）。值得注意的是，VOx 的體積能量密度 ||VN的ASY-SCs也遠高於準/全固態SCs[[166]、[167]、[168]、[169]、[170]、[171]、[172]]，如G基SCs（0.06 mWh cm，PVA ⁻³ /H ₃ PO ₄ ）[167]，MnO ₂ 碳顆粒（CNPs）SCs（0.09 mWh cm，0.5 ⁻³ mA cm，PVA ⁻² /H ₃ PO ₄ ）[168]和TiN基SCs（0.045 mWh cm，PVA ⁻³ /KOH）[170]等。

In short, As an active material for SCs, the electrochemical performance of VN is affected by various factors, including synthesis methods, grain sizes, film thickness etc. Presently The capacitance, energy density of VN electrode for SCs has been much enhanced, yet VN it still unable to be used on a large scale because of poor cycling stability, which causes the capacitance loss during charging and discharging [60,[173], [174], [175], [176]]. Therefore, for the purpose of improving the electrochemical performance of SCs, researchers have focused on fabricating various other TMN and VN composites through mixing VN with TMN or carbon materials. Details are given in subsequent chapters.
總之，作為SCs的活性材料，VN的電化學性能受到多種因素的影響，包括合成方法、晶粒尺寸、膜厚等。 目前，用於SC的VN電極的電容、能量密度已經大大增強，但VN由於迴圈穩定性差，仍然無法大規模使用， 這會導致充電和放電過程中的電容損失[60，[173]，[174]，[175]，[176]]。因此，為了提高SCs的電化學性能，研究人員專注於通過將VN與TMN或碳材料混合來製備各種其他TMN和VN複合材料。詳見後續章節。

3.1.2. TiN

Titanium Nitride (TiN) is a low-cost TMN with good electrical conductivity (4000 ≤ Ω ≤ 55500 s cm⁻¹) stability and mechanical properties [115,[177], [178], [179]]. It has been widely used in microelectronics, semiconductor device electrodes, catalytic materials, fuel cells, hard wear-resistant coatings etc. fields [143,180]. In addition, TiN has been used in SCs electrodes because it is a supercapacitive materials that can provide fast chare transfer and efficient charge collection [111]. Tang et al. [181] used urea and titanium chloride as precursors to synthesize titanium nitride. The authors obtained the specific capacitance was from 407 F g⁻¹, to 385 F g⁻¹, 364 F g⁻¹ and 312 F g⁻¹, with the current density changed from 1 A g⁻¹, 2 A g⁻¹, 5 A g⁻¹and 10 A g⁻¹ by cyclic voltammetry, and showed the specific volume loss of about 9.8% after 20,000 cycles at 50 mV s⁻¹.
氮化鈦（TiN）是一種低成本的TMN，具有良好的導電性（4000≤ Ω ≤55500 s cm ⁻¹ ）穩定性和機械性能[115，[177]，[178]，[179]]。已廣泛應用於微電子、半導體器件電極、催化材料、燃料電池、硬耐磨塗料等領域[143,180]。此外，TiN已被用於SC電極，因為它是一種超電容材料，可以提供快速的電容轉移和高效的電荷收集[111]。Tang等[181]以尿素和氯化鈦為前體合成氮化鈦。作者通過迴圈伏安法得到的比電容為407 F g ⁻¹ ，為385 F g，364 ⁻¹ F g ⁻¹ 和312 F g ⁻¹ ，電流密度從1 A g ⁻¹ 、2 A g ⁻¹ 、5 A g ⁻¹ 和10 A g ⁻¹ 變化，在50 mV s ⁻¹ 下迴圈20,000次后，比體積損失約為9.8%。

Generally speaking, the various methods had been adapted to synthesize titanium nitride of different morphology [16,77,131,[182], [183], [184], [185], [186]], including cauliflower [182], Chrysanthemum-like [2], corn-like [77] or nanotube-TiN [187] etc. (Fig. 9a and b,c,d). For example, Yang [77] et al. prepared corn-like TiN with lengths of about 4 μm by hydrothermal method and atomic layer deposition (ALD) method (Fig. 9 c). The fabricated corn-like TiN electrode showed a high volumetric capacitance of 1.5 mW h cm⁻³ and negligible capacitance loss after 20,000 cycles. Moreover, Many researchers have devoted themselves to synthesize titanium nitride with different structures, including nanorods TiN (TiN NRs) [188], mesoporous TiN [178], TiN rod [77] and TiN nanocrystallites [111]. On one hand, The TiN electrode with different morphology and structures not only enlarge the specific surface area of the electrode materials, but also provide more contact sites and more convenient penetration channels for the redox reaction, furthermore, improve the utilization rate of the electrode materials. On the other hand, TiN nanoparticles are interrelated to each other to form orderly nanostructures, which can effectively reduce the contact resistance between nanoparticles. Dong et al. [178] reported a facile route to directly change TiO₂ mesoporous spheres into TiN mesoporous spheres with the diameter of about 200–300 nm under using cyanamide to retain the morphology, which showed the largest single electrode specific capacitance of 133 F g⁻¹ at 2 mV s⁻¹. Qin [187] reported the self-supporting and non-binder hierarchical porous nanoparticles (H-TiN NPs) electrode successfully synthesized by electrochemical anodization and then annealing of titanium foil. Another way was to directly prepare TiN nanotubes (TiN NTs) electrode on flexible titanium foil. By comparing the TiN electrodes prepared of these two methods, the author found that the H-TiN NPS electrode had a higher volume capacitance (120 F cm⁻³) than TiN NTs (69 F cm⁻³) at a current density of 0.83A cm⁻³, and the Brunne-Emmet-Teller (BET) specific surface of H-TiN NTs electrode of 23.1 m² g⁻¹ was superior to TiN NTS electrode of 13.8 m² g⁻¹, because the H-TiN NTs electrode with hierarchical pore distribution provided more active sites for charge storage. Flexible all-solid-state sym-SCs (H-TiN NTs || H-TiN NTs) were consisting of two H-TiN NPS electrodes exhibited a high volume capacitance of 5.9 F cm⁻³ and a notable energy density of 0.53 mWh cm⁻³ at current density of 0.02 A cm⁻³. Flexible SCs have excellent cyclic stability, and the capacitance retention rate was 99% after 3000 cycles. Choi et al. [115] investigated TiN nanocrystals were synthesized by TiCl₄ (l)-NH₃ (g) reaction at room temperature for the application of SCs with a specific surface area of 128 m² g⁻¹, which were obtained from nitrogen adsorption measurements. They displayed the specific capacitance decreased from 238 to 24 F g⁻¹ in 1 M KOH aqueous electrolyte with an increase in the synthesis temperature and scan rates. We can know that the slight increase in total capacitance was may be due to an increase in the approachable surface area as electrolytes gradually penetrated into the pores with time.
一般而言，各種方法已適用於合成不同形態的氮化鈦[16,77,131，[182]，[183]，[184]，[185]，[186]]，包括花椰菜[182]、菊花樣[2]、玉米樣[77]或納米管TiN[187]等（圖9a和b，c，d）。例如，Yang[77]等人通過水熱法和原子層沉積（ALD）法制備了長度約為4 μm的玉米狀TiN（圖9 c）。製備的玉米狀TiN電極具有1.5 mW h cm ⁻³ 的高體積電容，20,000次迴圈后的電容損耗可忽略不計。此外，許多研究人員致力於合成不同結構的氮化鈦，包括納米棒TiN（TiN NRs）[188]、介孔TiN[178]、TiN棒[77]和TiN納米晶[111]。一方面，不同形貌和結構的TiN電極不僅擴大了電極材料的比表面積，而且為氧化還原反應提供了更多的接觸位點和更方便的穿透通道，進一步提高了電極材料的利用率。另一方面，TiN納米顆粒相互關聯，形成有序的納米結構，可以有效降低納米顆粒之間的接觸電阻。Dong等[178]報導了一種在氰胺保留形貌下直接將TiO ₂ 介孔球體轉變為直徑約200–300 nm的TiN介孔球體的簡單途徑，在2 mV s ⁻¹ 處顯示出最大的單電極比電容為133 F g ⁻¹ 。 Qin [187]報導了通過電化學陽極氧化和鈦箔退火成功合成的自支撐非粘結劑多級多孔納米顆粒（H-TiN NPs）電極。另一種方法是直接在柔性鈦箔上製備TiN納米管（TiN NTs）電極。通過比較這兩種方法製備的TiN電極，發現在0.83A cm的電流密度下，H-TiN NPS電極的體積電容（120 F cm ⁻³ ）高於TiN NTs（69 F cm ⁻³ ），H-TiN NTs電極的Brunne-Emmet-Teller（BET）比表面為23.1 m ² g ⁻¹ ，優於TiN NTS電極的13.8 m ² g ^{−1 −3} ，因為具有分層孔隙分佈的H-TiN NTs電極為電荷存儲提供了更多的活性位點。柔性全固態 sym-SC （H-TiN NTs ||H-TiN NTs）由兩個H-TiN NPS電極組成，在電流密度為0.02 A cm ⁻³ 時，表現出5.9 F cm ⁻³ 的高體積電容和0.53 mWh cm ⁻³ 的顯著能量密度。柔性SC具有優異的循環穩定性，3000次迴圈后電容保持率為99%。Choi等[115]研究了TiN納米晶體在室溫下通過TiCl ₄ （l）-NH ₃ （g）反應合成，用於應用比表面積為128 m ² g ⁻¹ 的SCs，這些納米晶體是通過氮氣吸附測量得到的。他們表明，隨著合成溫度和掃描速率的增加，1 M KOH水性電解質中的比電容從238 F g降低到24 F g ⁻¹ 。 我們可以知道，總電容的輕微增加可能是由於電解質隨著時間的推移逐漸滲透到孔隙中，可接近的表面積增加。

1. Download : Download high-res image (838KB)
   下載：下載高解析度影像（838KB）
2. Download : Download full-size image
   下載：下載全尺寸圖像

Fig. 9. (a) Cauliflower-like TiN [182]. Copyright 2014 Elsevier. (b) Chrysanthemum-like TiN [2]. Copyright 2018 Elsevier. (c) Corn-like TiN [77]. Copyright 2015 WILEY-VCH. (d) Nanotubes TiN [187]. Copyright 2018 Royal Society of Chemistry. (e) Schematic of the β-N in the annealed TiN surface, (f) N1s high resolution XPS spectra for TiN electrode after annealing after annealing at 550 °C. (g) Cyclic voltamograms curves at scan rate of 10 mV s⁻¹ for TiN electrodes before and after annealing [178]. Copyright 2017 Elsevier.
圖 9.（a）花椰菜狀TiN[182]。版權所有 2014 Elsevier。（b）菊花狀TiN [2]。版權所有 2018 Elsevier。（c）玉米狀TiN[77]。版權所有 2015 WILEY-VCH。（d）納米管TiN[187]。版權所有 2018 英國皇家化學學會。（e）退火TiN表面β-N示意圖，（f）在550 °C退火後退火后TiN電極的N1s高解析度XPS譜圖。 （g）退火前後TiN電極在10 mV s ⁻¹ 掃描速率下的迴圈伏特圖曲線[178]。版權所有 2017 Elsevier。

The capacitance of the electrodes is close related not only to the morphology of electrode, but also to the oxide layer formed on the surface of the electrodes. Preliminary studies showed that the capacitance of the electrodes with nano-TiN decreases with the formation of surface oxide layer [189]. Such as, Gray et al. [190] showed that both thermal and electrochemical oxidation (thermal oxidation-TO, Potential step oxidized-PO) increased the sites of surface redox active oxides. With the increase sites of surface oxides in KOH medium, the decrease of activity of storage charge oxides through TO treatment. When TiN circulated under positive potential, the electrochemical oxidation of the surface would produce thicker oxide layer, thus increasing the capacitance. It can be seen Table 2. This excellent electrochemical performance was mainly attributed to the increase of electrochemical active oxides generated on the surface, not to the increase of surface area [77,111,112,191,192]. To further explore the energy storage mechanism of TiN. Choi [115] indicated that the capacitance of the TiN electrodes came from the anions and cations, which adsorbed on the surface, i.e. the oxide layer on the surface. TiN was oxidized in alkaline medium by the following reactions:(6)$\text{TiN}+2{\text{OH}}^{-}+{\text{H}}_2\text{O}\iff {\text{HTiO}}_3^{-}+{\text{NH}}_3+{\text{e}}^{-}$(7)$4{\text{HTiO}}_3^{-}+2{\text{K}}^{+}+{\text{nH}}_2\text{O}\iff {\text{K}}_2{\text{Ti}}_4{\text{O}}_9{\text{nH}}_2\text{O}+{2\text{OH}}^{-}+{\text{H}}_2\text{O}$
電極的電容不僅與電極的形貌密切相關，而且與電極表面形成的氧化層密切相關。初步研究表明，納米TiN電極的電容隨著表面氧化層的形成而減小[189]。例如，Gray等[190]表明，熱氧化和電化學氧化（熱氧化-TO，勢階梯氧化-PO）都增加了表面氧化還原活性氧化物的位點。隨著KOH介質中表面氧化物位點的增加，TO處理后儲存電荷氧化物活性降低。當TiN在正電位下迴圈時，表面的電化學氧化會產生更厚的氧化層，從而增加電容。如表2所示。這種優異的電化學性能主要歸因於表面產生的電化學活性氧化物的增加，而不是表面積的增加[77,111,112,191,192]。進一步探索TiN的儲能機理。Choi[115]指出，TiN電極的電容來自吸附在表面的陰離子和陽離子，即表面的氧化層。TiN在鹼性介質中通過以下反應氧化： (6)$\text{TiN}+2{\text{OH}}^{-}+{\text{H}}_2\text{O}\iff {\text{HTiO}}_3^{-}+{\text{NH}}_3+{\text{e}}^{-}$ (7)$4{\text{HTiO}}_3^{-}+2{\text{K}}^{+}+{\text{nH}}_2\text{O}\iff {\text{K}}_2{\text{Ti}}_4{\text{O}}_9{\text{nH}}_2\text{O}+{2\text{OH}}^{-}+{\text{H}}_2\text{O}$

Table 2. Areal capacitance values of as prepared TiN foils and of foils that have previously been subjected to.
表 2.製備的TiN箔和先前經受過的箔的面電容值。

Electrode treatment 電極處理	Area capacitance based on AFM surface area (or based on electrode geometric area)/μF cm−2 基於AFM表面積（或基於電極幾何面積）的面積電容/μF cm −2
	Initial 1000 mV s−1 set,5th scan 初始 1000 mV s −1 設置，第 5 次掃描	1 mV s−1 set,5th scan 1 mV s −1 設置，第 5 次掃描	Final 1000 mV s−1 set,5th scan 最終 1000 mV s −1 設置，第 5 次掃描
As prepared	30.7 (215)	915 (6410)	35.1 (246)
TO 250 °C 24 h 至250°C 24小時	20.2 (97.0)	200 (960)	92.2 (443)
TO 350 °C24 h 至 350 °C24 小時	9.07 (43.5)	184 (883)	15.5 (74.4)
PO 0.5 V 100 s PO 0.5 V 100 秒	43.5 (222)	709 (3620)	61.2 (312)
PO 1.0 V 100 s PO 1.0 V 100 秒	34.9 (178)	305 (1560)	83.1 (424)
PO 1.2 V 150 s PO 1.2 V 150 秒	13.2 (67.3)	2170 (11100)	30.1 (154)
PO 1.2 V 120 s PO 1.2 V 120 秒	19.9 (101)	1990 (10100)	56.1 (286)

Surface oxidation by TO or PO [190]. Copyright 2017 Royal Society of Chemistry.
TO或PO的表面氧化[190]。版權所有 2017 英國皇家化學學會。

However, Other researchers hold different views and showed that the storage charge of SCs electrodes depends on the on the stoichiometry of TiN film and the nitrogen content on the surface of the electrodes. Achour et al. [87] proposed that the charge storage mechanism of TiN superstoichiometric thin films were caused by the cumulative effect of electric double layer and redox reaction. While in stoichiometric or sub-stoichiometric films,it was contributed to the electric double layer. the area and volume capacitance of over-quantified stoichiometric TiN film were much larger than those of stoichiometric or sub-stoichiometric TiN films. The difference in electrochemical storage behavior was attributed to N-doped of the TiO₂ layer formed on the surface of the TiN films. They implied that N-doped TiO₂ was believed to cause oxygen vacancy defects, which were the center of OH⁻ adsorptionin over-quantified stoichiometric TiN film. They [87] directly linked the surface properties of natural oxides to their nitrogen content and found that nitrogen-rich TiN could retain its capacitance more effectively because N-doped of surface oxides increased its conductivity. Hence, The methord of increasing the energy density of SCs can be done not only by maximizing the surface area of the electrode [21,193,194], but also by doping with other elements (oxygen [195,196], nitrogen [197], or fluorine [198] on the surface of the electrodes. Achour et al. [199] reported that TiN film deposited by magnetron sputtering annealed in vacuum at 400 and 500 °C for 1 h. Thermal annealing could promote the diffusion of β-N atoms from the films, resulting in the replacement of oxygen and nitrogen in the titanium oxide layer and the accumulation of the remaining β-N atoms on the film surface. Compared with the prepared TiN films, the areal capacitance of N-doped TiN films increased 3-fold (8.2 mF cm⁻²) without sacrificing the cycling stability of the electrodes after more than 10,000 cycles (Fig. 9e–g).
然而，其他研究者持有不同的觀點，並表明SCs電極的儲存電荷取決於TiN薄膜的化學計量和電極表面的氮含量。Achour等[87]提出TiN超化學計量薄膜的電荷存儲機理是由雙電層和氧化還原反應的累積效應引起的。而在化學計量或亞化學計量薄膜中，它有助於電雙層。過量化學計量TiN薄膜的面積和體積電容遠大於化學計量或亞化學計量TiN薄膜。電化學存儲行為的差異歸因於TiN薄膜表面形成的TiO ₂ 層的N摻雜。他們認為，N摻雜的TiO ₂ 被認為會導致氧空位缺陷，這是OH在過度量化的化學計量TiN薄膜中吸 ⁻ 附的中心。他們[87]將天然氧化物的表面特性與其氮含量直接聯繫起來，發現富氮TiN可以更有效地保持其電容，因為表面氧化物的N摻雜增加了其電導率。因此，提高SCs能量密度的方法不僅可以通過最大化電極的表面積[21,193,194]來實現，還可以通過在電極表面摻雜其他元素（氧[195,196]，氮[197]或氟[198]來實現。Achour等[199]報導，通過磁控濺射沉積的TiN薄膜在400和500°C的真空下退火1小時。 熱退火可以促進β-N原子從薄膜擴散，導致氧化鈦層中的氧和氮置換，剩餘的β-N原子在薄膜表面積累。與製備的TiN薄膜相比，N摻雜TiN薄膜的面電容增加了3倍（8.2 mF cm ⁻² ），而電極在超過10,000次迴圈後迴圈穩定性不犧牲（圖9e-g）。

Although TiN as a high-performance SCs electrode material, it was unable to meet people's requirements with the development of technology. One of the major drawbacks of TiN limited its applications, which was its poor electrochemical stability in aqueous electrolytes due to irretrievable oxidation reactions and structural degradation [200].
雖然TiN作為一種高性能的SCs電極材料，但隨著技術的發展，它已無法滿足人們的要求。TiN的主要缺點之一限制了其應用，即由於不可恢復的氧化反應和結構退化，TiN在水電解質中的電化學穩定性較差[200]。

3.1.3. Mo_xN 3.1.3. _x 鉬

Molybdenum nitride (MoN_x) has been used as an active electrode materials for SCs due to its high electrochemical activity, extraordinarily conductivity and excellent electrochemical decomposition performance of water-resistant electrolytes [128,[201], [202], [203]]. Deng et al. [204] studied molybdenum nitride (γ-Mo₂N) with TaO_x as effective charge storage materials as early as 1998. Liu et al. [205] explored a promising alternative to molybdenum nitride (Mo₂N, MoN) as SCs electrode because of its low cost and high abundance.
氮化鉬（MoN _x ）因其高電化學活性、超強的導電性和優異的耐水電解質電化學分解性能而被用作SCs的活性電極材料[128，[201]，[202]，[203]]。鄧等[204]早在1998年就研究了氮化鉬（γ-Mo ₂ N）與TaO _x 作為有效電荷儲存材料。Liu等[205]探索了一種有前途的氮化鉬（Mo ₂ N，MoN）替代品作為SCs電極，因為它成本低，豐度高。

Molybdenum nitride (MoN_x) had various phases: disordered nitrogen vacancies [206], hexagonal phase δ₁-MoN (WC type), δ₂-MoN (NiAs type) δ₃-MoN (FeS type), γ-MoN_x, and α-MoN₂ (Fig. 10 a). The most studied of MoN_x were the rock salt type γ- and hexagonal type δ-phase [207,208]. The preparation process of the molybdenum nitride electrode for SCs were usually carried out by metal molybdenum or molybdenum oxide, and subjected to thermal nitridation by NH₃ gas under high temperature conditions [205]. While, The different phases of MoN [135,[209], [210], [211]] were affected by temperature and concentration of reducing gas. The rocksalt type γ-Mo₂N was yielded by ammonolysis of MoCl₅ in chloroform heating in ammonia at 600–800 °C [212]. Only one example has been reported of the formation of γ-Mo₂N was generated in a slow decomposition of [Mo₂ (NMe₂)₆] slow decomposition at 450 °C [213]. However, Imran [135] et al. reported that cubic γ-Mo₂N or hexagonal δ₁-MoN were obtained from the reaction MoCl₅ or Mo(NMe₂)₄ with NH₃, which mainly depending on the reaction temperature and time (Fig. 10 b,d). δ₁-MoN could be formed at a high temperature (800–1000 °C) aminolysis of Mo(NMe₂)₄ or aminolysis of MoCl₅ at the temperature lower than 500 °C. However, γ-Mo₂N can be formed from two precursors of MoCl₅ at a temperature 700–1000 °C or Mo(NMe₂)₄ higher than 900 °C. Ting et al. [209] synthesized a thin film molybdenum nitride pseudocapacitor electrode at low temperature (400 °C), and found that the pseudocapacitance behavior of film electrode surface treated by nitrogen was superior to the treatment by ammonia nitrogen. Chen et al. [88] deposited (111)-oriented γ-Mo₂N films by reactive magnetron DC sputtering, explained that the high specific capacitance of γ-Mo₂N films with thickness less than 750 nm can achieve 722 F cm⁻³ at 5 mV s⁻¹, and hold 100% capacitance after 2000 cycles. The author suggested that the electrochemical behavior of γ-Mo₂N films depended not only on the deposition temperature (400 °C optimum), but also on the concentration of nitrogen in Ar-N₂ mixture (x = 0.35 optimum), and deposition time (0.5 h optimum).
氮化鉬（MoN _x ）具有不同的相：無序氮空位[206]，六方相 ₁ δ-MoN（WC型）， ₂ δ-MoN（NiAs型）， ₃ δ-MoN（FeS型），γ-MoN _x 和α-MoN ₂ （圖10a）。對MoN _x 研究最多的是岩鹽型γ和六方型δ相[207,208]。SCs氮化鉬電極的製備過程通常採用金屬鉬或氧化鉬進行，並在高溫條件下進行 ₃ NH氣體熱氮化[205]。而MoN的不同相[135，[209]，[210]，[211]]受還原氣體溫度和濃度的影響。γ-Mo ₂ N型岩鹽是在600–800°C的氨水中氯仿加熱中由MoCl ₅ 氨解而得的[212]。在450°C下，[Mo ₂ （NMe ₂ ） ₆ ]的緩慢分解中，只有一例生成γ-Mo ₂ N[213]。然而，Imran[135]等人報導，立方γ-Mo ₂ N或六方δ-MoN ₁ 是從MoCl ₅ 或Mo（NMe ₂ ） ₄ 與NH的反應中獲得的 ₃ ，這主要取決於反應溫度和時間（圖10 b，d）。在高溫（800–1000 °C）下，Mo（NMe ₂ ） ₄ 的氨解或MoCl ₅ 在低於500 °C的溫度下，可形成 ₁ δ-MoN。 然而，γ-Mo ₂ N可以在700-1000°C或Mo（NMe ₂ ） ₄ 高於900°C的溫度下由MoCl的兩個前體形成。 ₅ Ting等人。 [209] 在低溫（400 °C）下合成了薄膜氮化鉬贗電極，發現氮氣處理的薄膜電極表面的贗電容行為優於氨氮處理。Chen等[88]通過反應式磁控直流濺射沉積了（111）取向的 ₂ γ-Mo N薄膜，並解釋說，厚度小於750 nm的 ₂ γ-Mo N薄膜的高比電容可以在5 mV s ⁻¹ 時達到722 F cm ⁻³ ，並在2000次迴圈后保持100%的電容。作者認為，γ-Mo ₂ N薄膜的電化學行為不僅取決於沉積溫度（最適400°C），還取決於Ar-N ₂ 混合物中氮的濃度（x = 0.35最優）和沉積時間（最適0.5 h）。

1. Download : Download high-res image (1MB)
   下載：下載高解析度影像（1MB）
2. Download : Download full-size image
   下載：下載全尺寸圖像

Fig. 10. (a) The structures of some molybdenum nitride phases, (b,d) TEM images of δ₁-MoN and Variation of specific capacitance of δ₁-MoN in a) H₂SO₄ and b) K₂SO₄ electrolyte [135]. Copyright 2014 Elsevier. (c,e) TEM images of ϒ-MoN, Variation of specific capacitance of δ₁-MoN in H₂SO₄ and KCl [215]. Copyright 2009 Elsevier. (f) Moles of inserted proton and electrons transferred, (g) Mesoporous MoN mechanism for storing charge [192]. Copyright 2017 Elsevier.
圖 10.（a）氮化鉬相的結構，（b，d） ₁ δ-MoN的TEM圖像和 ₁ δ-MoN在a）H ₂ SO ₄ 和b）K ₂ SO ₄ 電解質中的比電容變化[135]。版權所有 2014 Elsevier。（c，e）Υ-MoN的TEM圖像， ₁ δ-MoN在H ₂ SO ₄ 和KCl中的比電容變化[215]。版權所有 2009 Elsevier。（f）插入質子的摩爾數和轉移的電子，（g）用於儲存電荷的介孔MoN機制[192]。版權所有 2017 Elsevier。

Very recently, some reports showed that MoN_x was used as charge storage materials [211,214,215], and the preparation of MoN with large specific surface area can raise the electrode capacitance. Like mesoporous MoN [217,218], porous nanoribbons MoN [125] and MoN nanocrystals [135,215]. Liu et al. [125] successfully synthesized molybdenum nitride (Mo₂N) nanoribbons with high density, ultrafine nanopore with a maximum diameter of 3.4 nm by topological chemical transformation of single crystal molybdenum oxide (MoO₃) nanoribbons. The prepared Mo₂N nanoribbon electrodes had the maximum specific capacitance of 160 F g⁻¹ at the high scanning rate of 100 mV s⁻¹. Li et al. [215] prepared super fine nanoparticles of molybdenum nitride (γ-Mo₂N) by temperature programmed reaction at high temperature. When the nanoparticles γ-Mo₂N with an average diameter of 16 nm maintained about 95% of the original specific capacities after 6000 cycles at 1 mV s⁻¹ in 1 M H₂SO₄ or 1 M KCl electrolyte solution (Fig. 10 c,e).
最近，一些報導表明，MoN _x 被用作電荷存儲材料[211,214,215]，製備比表面積大的MoN可以提高電極電容。與介孔MoN[217,218]、多孔納米帶MoN[125]和MoN納米晶體[135,215]一樣。Liu等[125]通過對單晶氧化鉬（MoO ₃ ）納米帶進行拓撲化學轉化，成功合成了高密度、最大直徑為3.4 nm的高密度氮化鉬（Mo ₂ N）納米帶。在100 mV s ⁻¹ 的高掃描速率下，製備的Mo ₂ N奈米帶電極的最大比電容為160 F g ⁻¹ 。Li等[215]通過高溫程式化鉬（ ₂ γ-Mo N）的超細納米顆粒。當平均直徑為16 nm的納米顆粒γ-Mo ₂ N在1 M H ₂ SO ₄ 或1 M KCl電解質溶液中以1 mV s ⁻¹ 迴圈6000次后保持約95%的原始比容量時（圖10 c，e）。

Other researchers also suggested the difference of electrode electrochemical performance in different electrolytes. Imran et al. [135] showed that the Mo₂N nanocrystals derived from Mo(NMe₂)₄ could provide a strong feature of redox reaction and higher capacitance, because the reduction peak of Mo₂N shifted from −0.42 V to −0.52 V in K₂SO₄ electrolyte and from −0.35 V to −0.30 V in H₂SO₄ electrolyte (Fig. 10 b,d). Furthermore, The conductivity and radius of cations in aqueous electrolytes containing K⁺ (aq) were restricted with high performance electrodes [219,220]. Djire [221] and Peder [113] explored the mechanism of charge storage in porous MoN as follows:(8)${\text{Mo}}_2^{\mathrm{\delta }}\text{N}+{2\text{H}}^{+}+4{\text{e}}^{-}\leftrightarrow {\text{Mo}}_2^{\mathrm{\delta }-1}\text{N}{\left(\text{H}\right)}_2$
其他研究人員還提出了不同電解質中電極電化學性能的差異。Imran等[135]表明，由於鉬在鉬 _{2 4} 電解質中的還原峰 ₂ 從−0.42 V移至−0.52 V，在H ₂ SO ₄ 電解質中從−0.35 V移至−0.30 V，因此源自Mo（NMe ₂ ） ₄ 的Mo ₂ N納米晶具有強烈的氧化還原反應特徵和更高的電容（圖10 b，此外，含K ⁺ （aq）的水性電解質中陽離子的電導率和半徑受到高性能電極的限制[219,220]。Djire[221]和Peder[113]探討了多孔MoN中電荷存儲的機理如下： (8)${\text{Mo}}_2^{\mathrm{\delta }}\text{N}+{2\text{H}}^{+}+4{\text{e}}^{-}\leftrightarrow {\text{Mo}}_2^{\mathrm{\delta }-1}\text{N}{\left(\text{H}\right)}_2$

MoN storage charge was mainly coupled by microporous electrons (e⁻) and protons (H⁺) in charge transfer process, and involved the principle of proton coupled electron transfer (Fig. 10f and g). The pore sizes of electrode material played an important role in the electrochemical active surface area [222]. This unforgettable total storage capacitance of 1560 F g⁻¹ may be attributed to the high porosity in the material and rapid transport of protons [134], which was consistent with the results of the [219] experiment. Therefore, Mo₂N is a promising electrode material for SCs.
MoN儲能電荷在電荷轉移過程中主要由微孔電子（e ⁻ ）和質子（H ⁺ ）耦合，涉及質子耦合電子轉移原理（圖10f和g）。電極材料的孔徑在電化學活性表面積中起著重要作用[222]。1560 F g ⁻¹ 的令人難忘的總存儲電容可能歸因於材料中的高孔隙率和質子的快速傳輸[134]，這與[219]實驗的結果一致。因此，Mo ₂ N是一種很有前途的SC電極材料。

3.1.4. CrN 3.1.4. 鉻

The cubic structure of Chromium nitride has been widely used in semiconductor technology such as optoelectronics and MEMS applications due to its large band gap [223,224]. At present, some studies have been carried out in energy devices of SCs [[91], [92], [93], [94], [95], [96]]. However, Dans et al. [92] reported that the CrN nanoparticles with the size of 20–30 nm subsequently obtained from chromium-urea complex compound and showed a remarkable specific capacitance of 75 F g⁻¹ at the current density of 30 mA g⁻¹ in the non-aqueous electrolyte. Arifet al. [93] deposited CrN films on 304 L steel substrates by reactive magnetron DC sputtering, The as fabricated CrN film displayed the specific capacitance of 41.6 F g⁻¹ in 1 M Na₂SO₄ at the scan rate of 5 mV s⁻¹ and could reached a high capacitance retention of 87% after 2000 cycles. Although CrN films were deposited by reactive magnetron DC sputtering were potential electrode materials for SCs, there were still existed a lower capacitances, The specific capacitance of CrN films was only 12.8 mF cm⁻² at 1.0 mA cm⁻² [91]. Haye [96] et al. reported that the CrN films of different tilts have been created by magnetron sputtering at glancing angle (GLAD). According to the deposition flux of magnetron sputtering, they changed the inclination of the substrate, a well column can be formed mainly because the ballistic shadow (Fig. 11a–c). They found that a high areal capacitance of 35.4 mF cm² is obtained at 45° or 60°, at 1.2 mA cm², in 0.5 M H₂SO₄ electrolyte) with an outstanding cycling stability over 10,000 cycles (Fig. 11 d), In addition, they applied GLD technology to the chip interdigitated micro-supercapacitors (MSCs) to obtain the highest energy density and power density. On chip interdigitated micro-supercapacitors (MSCs) were assembled with a maximum energy density of 2 μWh cm⁻² (15.3 mWh cm⁻³) at a power density of 20 μWh cm⁻² (Fig. 11 e).
氮化鉻的立方結構由於其較大的帶隙而廣泛應用於光電子學和MEMS等半導體技術[223,224]。目前，已經在SC的能源器件中進行了一些研究[[91]，[92]，[93]，[94]，[95]，[96]]。然而，Dans等[92]報導，隨後從鉻-脲絡合物中獲得尺寸為20-30 nm的CrN納米顆粒，並在非水電解質中顯示出75 F g ⁻¹ 的顯著比電容，電流密度為30 mA g ⁻¹ 。Arifet [93]採用反應式磁控直流濺射法在304 L鋼基板上沉積CrN薄膜，在5 mV s ⁻¹ 的掃描速率下，CrN薄膜在1 M Na ₂ SO ₄ 中表現出41.6 F g ⁻¹ 的比電容，在2000次迴圈后可達到87%的高電容保持率。雖然CrN薄膜是通過反應磁控直流濺射沉積的，但仍存在較低的電容，CrN薄膜的比電容僅為12.8 mF cm，1.0 ⁻² mA cm ⁻² [91]。Haye[96]等人報導了不同傾斜度的CrN薄膜是由磁控濺射在掠角（GLAD）下產生的。根據磁控濺射的沉積通量，它們改變了襯底的傾角，形成井柱主要是因為彈道陰影（圖11a-c）。他們發現，在 45° 或 60° 處、在 1.2 mA cm ² 處，在 0.5 M H ₂ SO ₄ 電解質中獲得了 35.4 mF cm ² 的高面電容，在 10,000 次迴圈中具有出色的循環穩定性（圖 1）。 11 d），此外，他們將GLD技術應用於晶元交錯微型超級電容器（MSCs），以獲得最高的能量密度和功率密度。片上指狀微型超級電容器（MSCs）以20μWh cm ⁻² 的功率密度組裝，最大能量密度為2 μWh cm ⁻² （15.3 mWh cm ⁻³ ）（圖11 e）。

1. Download : Download high-res image (1MB)
   下載：下載高解析度影像（1MB）
2. Download : Download full-size image
   下載：下載全尺寸圖像

Fig. 11. (a) Schematic of the Conventional and GLAD sputtering, Cross section SEM images and Top view SEM images of CrN films, (b) CrN 0°, (c) CrN60°, (d) Comparison of cyclic voltamograms of CrN electrodes in 0.5 M H₂SO₄, (e) Micro-supercapacitor fabrication and design optical image [96]. Copyright 2019 Elsevier. (f) Evolution of W₂N the specific surface vs the thickness, (g) Evolution of the areal capacitance extracted from electrochemical measurement vs the specific surface, extracted from AFM analyses, (h) Volumetric capacitance of W₂N films vs the thickness [89]. Copyright 2019 Elsevier.
圖 11.（a）常規和GLAD濺射示意圖，CrN薄膜的截面SEM圖像和頂視圖SEM圖像，（b）CrN 0°，（c）CrN60°，（d）0.5 M H ₂ SO ₄ 中CrN電極迴圈伏變圖的比較，（e）微型超級電容器的製造和設計光學圖像[96]。版權所有 2019 Elsevier。（f）比表面的W ₂ N隨厚度的變化，（g）從電化學測量中提取的面電容與從AFM分析中提取的特定表面的演變，（h）W ₂ N薄膜的體積電容與厚度的關係[89]。版權所有 2019 Elsevier。

3.2. Ternary TMN 3.2. 三元TMN

TMN composites materials, especially ternary TMN and TMN/TMN composite, have the ability to expand the physical phenomena of binary TMN, such as binary TMN with higher specific capacitance (such as VN) or binary TMN with higher specific rate (such as TiN), so ternary nitrides with good properties can be obtained. Anusha Thampi et al. [100] reported the of TiVN thin films with (200) preferred orientation structure deposited on stainless steel substrates by pulsed DC magnetron sputtering. The volume capacitance of TiVN electrode was 156 F cm⁻³ (maximum capacitance of 69 F g⁻¹) in 1 M Na₂SO₄ medium was inferior to the volume specific capacitance of 500 F cm⁻³ at 2 mV s⁻¹ in 1 M KOH medium. The supercapacitive behavior of ternary nitrides is influenced by the type of electrolytes, and the atomic ratio of two metals has a great influence on the capacitance of ternary nitrides. Achour et al. [101] deposited TiVN thin films with different Ti/V ratios on Si (001) substrates by DC magnetron sputtering. They found that the capacitance and energy storage of the electrodes depend on the Ti/V ratio in the films. The low content of V lead to an increase of cycling ability of electrodes at the expense of areal capacitance of thin films, while high V content increased the areal capacitance of electrodes but brought out a serious decrease of cycling behavior of electrodes. When Ti/V ratio was closed to 1.1, the TiVN thin films exhibited the highest areal capacitance of 15 mF cm⁻² along with the capacitance showed almost no attenuation after 10,000 cycles. Ternary nitrides have been proved to be cost-effective and shown good rate performance with electrochemical performance compared with single nitrides [54].
TMN複合材料，特別是三元TMN和TMN/TMN複合材料，具有擴展二元TMN物理現象的能力，如具有較高比電容的二元TMN（如VN）或具有較高比速率的二元TMN（如TiN），因此可以得到性能良好的三元氮化物。Anusha Thampi等[100]報導了TiVN薄膜通過脈衝直流磁控濺射沉積在不鏽鋼基板上的具有（200）優選取向結構。TiVN電極在1 M Na SO ₄ 介質中的體積電容為156 F cm ⁻³ （最大電容為69 F g ⁻¹ ），低於1 M KOH介質中2 mV s ⁻¹ 時500 F cm ⁻³ 的體積比電容。 ₂ 三元氮化物的超電容行為受電解質類型的影響，兩種金屬的原子比對三元氮化物的電容影響很大。Achour等[101]通過直流磁控濺射法在Si（001）襯底上沉積了具有不同Ti/V比的TiVN薄膜。他們發現電極的電容和能量存儲取決於薄膜中的Ti/V比。V含量低導致電極迴圈能力增加，但犧牲了薄膜的面電容，而高V含量增加了電極的面電容，但導致電極的循環行為嚴重下降。當Ti/V比接近1.1時，TiVN薄膜表現出最高的面電容，為15 mF cm ⁻² ，電容在10,000次迴圈后幾乎沒有衰減。與單一氮化物相比，三元氮化物已被證明具有成本效益，並且顯示出良好的電化學性能[54]。

Researchers have synthesized composite electrodes by combining two binary nitrides (TMN/TMN) and combining the advantages of the two TMN to further improve the areal capacitance and cycle life of SCs. In TMN, titanium nitride (TiN) exhibits better conductivity, but its capacitance is lower, while vanadium nitride (VN) has higher capacitance despite its poor performance [[228], [229], [230]]. The compound of Titanium nitride and vanadium nitride have been proved to have excellent storage performance because TiN/VN composite electrodes for SCs can allowed fast transfer of electrons [231] Dong et al. [186] prepared TiN/VN core-shell composite with the diameter ranging from 30 to 80 nm by coating of commercial TiN nanoparticles with V₂O₅ nH₂O sols and then ammonia reduction. The TEM images showed that TiN was core, VN was shell. The author found that the charge storage mechanism of TiN/VN electrodes was through adsorbing hydroxide ions at specific locations on the oxynitride surface. The maximum specific capacitance of 170 F g⁻¹ can be obtained at scanning rate of 2 mV s⁻¹ and the original capacitance maintained about 89% after 500 cycles.
研究人員通過結合兩種二元氮化物（TMN/TMN）並結合兩種TMN的優點合成了複合電極，以進一步提高SCs的面電容和循環壽命。在TMN中，氮化鈦（TiN）表現出更好的導電性，但其電容較低，而氮化釩（VN）儘管性能較差，但具有較高的電容[[228]，[229]，[230]]。氮化鈦和氮化釩的化合物已被證明具有優異的儲存性能，因為用於SC的TiN/VN複合電極可以允許電子的快速轉移[231] Dong等[186]通過用V ₂ O ₅ nH ₂ 塗覆商業TiN納米顆粒，製備了直徑範圍為30至80 nm的TiN/VN核殼複合材料O 溶膠，然後氨還原。透射電鏡圖像顯示，TiN為核心，VN為殼。作者發現TiN/VN電極的電荷存儲機理是通過吸附氮氧表面特定位置的氫氧根離子。在2 mV s ⁻¹ 的掃描速率下，可以獲得170 F g ⁻¹ 的最大比電容，並且在500次迴圈后原始電容保持在89%左右。

Although there were few studies on ternary nitrides and TMN composite materials, the results of the research on ternary nitrides or TMN composite electrodes have opened up new prospects for exploring other binary/ternary TMN electrodes for electrochemical storage devices, where the role of the different metal cations need to be investigated.
雖然對三元氮化物和TMN複合材料的研究較少，但對三元氮化物或TMN複合電極的研究結果為探索其他二元/三元TMN電極的電化學記憶體件開闢了新的前景，其中不同金屬陽離子的作用有待研究。

4.1. VN/C

Carbon materials were often used as electrode materials for SCs because of their large specific surface area, high cycling performance and low cost. However, the carbon materials of low specific capacitance as electrode materials limits their practical application in this field. However, VN have excellent conductivity and high specific volume, so the VN/C composite electrode can be prepared by combining TMN with carbon materials, so as to greatly improve the SCs electrochemical performance. For example, VN and carbon were compounded to form electrodes, such as VN and carbon nanotubes (VN/CNT), VN and graphene composites (VN/G) or VN and carbon nanosheets (VN/CNSs) etc. [56,83,101,105,105,119,[232], [233], [234], [235], [236], [237], [238], [239], [240]].
碳材料因其比表面積大、迴圈性能高、成本低等優點，常被用作SCs的電極材料。然而，低比電容的碳材料作為電極材料限制了其在該領域的實際應用。但VN具有優良的導電性和高比容，因此可以通過TMN與碳材料結合來製備VN/C複合電極，從而大大提高SCs的電化學性能。例如，將VN和碳複合形成電極，如VN和碳納米管（VN/CNT）、VN和石墨烯複合材料（VN/G）或VN和碳納米片（VN/CNSs）等[56,83,101,105,105,119，[232]，[233]，[234]，[235]，[236]，[237]，[238]，[239]，[240]]。

The 3D structure with stratified porosity could provide interconnected channels to ensure the convenience of electrolyte transportation and the accessibility of electrode materials. In this regard, so many efforts have been done by many groups. For example, Wang and others [80] reported that the elctrode of 3D VN porous nanoribbons with the lateral size of ~100 nm embed within the graphene composite (3D VNPN/G) depicted a capacitance of 164.4 F g⁻¹ at current density of 0.3 A g⁻¹ (Fig. 12 a), which was much higher than that of non-porous VN electrode materials (119 F g⁻¹). The author suggested the porous nanoribbons avoided particle boundary barriers and the graphene networks enhanced the charge transport in 3D VNPN/G composite. Graphene oxide (GO) is a derivative of graphene with excellent electrical, mechanical, and thermal properties, which can also be widely compounded with VN to form a high specific capacitance electrode material. He and Wang et al. [237] explored an electrochemical surface initiated atom transfer (SI-eATRP) technique combined with heat treatment approach to prepare VN nanoparticles and GO composite electrode VNNP@GO (Fig. 12 b). The VN crystal particles with the size of about 30 nm distributed uniformly inserting the surface of GO layers for the first time which replaced the traditional hierarchical porous method. The prepared VNNP@GO eletrode exhibited the capacitance of 109.7 F g⁻¹ at 5 mV s⁻¹ and maintained the specific capacitance above 93% after 5000 CV Cycles. Some researchers have been studied the electrochemical behavior of VN nanosheets and porous carbon composites. For example, Zhang et al. [238] demonstrated that the modification of interconnected porous carbon and VN hybird materials elctrode (m-IPC@VN) was obtained by the highly porous emulsion polymerization technology and heat treatment in ammonia (Fig. 12 c). The hybird elctrode of m-IPC@VN displayed the capacitance of 260 F g⁻¹ with a current density of 0.5 A g⁻¹. The asy-SCs (m-IPC@VN || Ni (OH)₂) was fabricated with Ni (OH)₂ exhibited high energy density of 40.5 Wh kg⁻¹ and power density of 3760.7 W kg⁻¹ [174].
具有分層孔隙率的三維結構可以提供互連通道，確保電解液運輸的便利性和電極材料的可及性。在這方面，許多團體已經做出了許多努力。例如，Wang等[80]報導，在石墨烯複合材料（3D VNPN/G）中嵌入橫向尺寸為~100 nm的3D VN多孔納米帶的電阻在電流密度為0.3 A g ⁻¹ 時表現出164.4 F g ⁻¹ 的電容（圖12 a），遠高於無孔VN電極材料（119 F g ⁻¹ ).作者認為多孔納米帶避免了顆粒邊界勢壘，石墨烯網路增強了3D VNPN/G複合材料中的電荷傳輸。氧化石墨烯（GO）是石墨烯的衍生物，具有優異的電學、機械和熱性能，也可以與VN廣泛複合，形成高比電容電極材料。他和Wang等[237]探索了一種電化學表面引發原子轉移（SI-eATRP）技術與熱處理方法相結合，製備VN納米顆粒和GO複合電極VNNP@GO（圖12b）。將尺寸約為30 nm的VN晶體顆粒均勻分佈在GO層表面，首次取代了傳統的分層多孔方法。製備的VNNP@GO eletrode在5 mV s ⁻¹ 時表現出109.7 F g ⁻¹ 的電容，並在5000 CV迴圈后將比電容保持在93%以上。一些研究人員已經研究了VN納米片和多孔碳複合材料的電化學行為。例如，Zhang等人。 [238]表明，通過高孔乳液聚合技術和氨熱處理，可以對互連的多孔碳和VN hybird材料elctrode（m-IPC@VN）進行改性（圖12 c）。m-IPC@VN 的 hybird elctrode 顯示電容為 260 F g ⁻¹ ，電流密度為 0.5 A g ⁻¹ 。asy-SC （m-IPC@VN ||Ni （OH） 與 Ni （OH） _{2 2} 一起製造，表現出 40.5 Wh kg 的高能量 ⁻¹ 密度和 3760.7 W kg 的功率密度 ⁻¹ [174]。

1. Download : Download high-res image (3MB)
   下載 ： 下載高解析度影像 （3MB）
2. Download : Download full-size image
   下載：下載全尺寸圖像

Fig. 12. (a) Very mature ultra-concentrated emulsion polymerization technology [80]. Copyright 2018 Springer. (b) Hummers method and hydrothermal synthesis [237]. Copyright 2018 Elsevier. (c) Combining electrochemically controlled surface-initiated atom transfer (SI-eATRP) technique and thermal-treatment method [238]. Copyright 2019 Elsevier. SEM images of (d₁) VN-0, (d₂) N-CNS/VNNPs-2, (d₃) N-CNS/VNNPs-1, (d₄) N-CNS/VNNPs-0, (e) Electrochemical performance of N-CNS/VNNPs [56]. Copyright 2018 Nature. (f₁-f₆) CV curves (50 mV s⁻¹) and the separation of contributions from capacitive and diffusion-controlled process of VN electrodes in different electrolytes [1174]. Copyright 2018 Elsevier. (g₁) Schematic representation for fabrication strategy of CNS@VN, Electrochemical performances of CNS@VN, (g₂) CV curve at the specific sweep rate of 5 mV s⁻¹ (the shaded region shows the capacitive contribution to the total current), (g₃) coulombic efficiency and cycling life measured at the current density of 5 A g⁻¹ [232]. Copyright 2018 Elsevier. Schematic illustrations of (h₁) the fabrication of the ACFSS, (h₂) Normalized capacitances of the as-prepared ACFSS bent 90° for 5,000 cycles [143]. Copyright 2017 American chemical society.
圖 12.（a）非常成熟的超濃縮乳液聚合技術[80]。版權所有 2018 Springer。（b）悍馬法和水熱合成[237]。版權所有 2018 Elsevier。（c）結合電化學控制表面引發原子轉移（SI-eATRP）技術和熱處理方法[238]。版權所有 2019 Elsevier。（d ₁ ）VN-0，（d ₂ ）N-CNS/VNNPs-2，（d ₃ ）N-CNS/VNNPs-1，（d ₄ ）N-CNS/VNNPs-0，（e）N-CNS/VNNPs的電化學性能[56]。版權所有 2018 Nature。（女 ₁ -女 ₆ ）CV曲線（50 mV s ⁻¹ ）以及不同電解質中VN電極的電容和擴散控制過程的貢獻分離[1174]。版權所有 2018 Elsevier。（七 ₁ ）CNS@VN的製造策略示意圖，CNS@VN的電化學性能，（g ₂ ）5 mV s ⁻¹ 比掃描速率下的CV曲線（陰影區域顯示電容對總電流的貢獻），（g ₃ ）庫侖效率和在5 A g ⁻¹ 電流密度下測得的迴圈壽命[232]。版權所有 2018 Elsevier。（h ₁ ）ACFSS的製造示意圖，（h ₂ ）ACFSS的歸一化電容彎曲90°，持續5,000次迴圈[143]。版權所有 2017 美國化學學會。

Generally speaking, the pH value in the synthetic system, and the types of electrolytes which has many forms: water system, organic electrolytes and ILS are all played a significant role in the VN/C composite electrode. For example, The author [56] reported that a new hybrid electrode N-doped Carbon Nanosheets/Vanadium Nitride Nanoparticles (N-CNS/VNNPs) were fabricated at different pH values (0, 1, and 2) through surface-initiated in-situ intercalative polymerization process, which were marked as N-CNS/VNNPs-0, N-CNS/VNNPs-1, and N-CNS/VNNPs-2, respectively, and found that the size of carbon nanosheets and VN nanoparticles decreased at nanoscale as the PH value decreased from 2 to 0 which resulted in the increasing of specific capacitance of N-CNS/VNNPs (up to high 280 F g⁻¹ at 1 A g⁻¹) (Fig. 12 d₁-d₄,e)The N-CNS/VNNPs electrode and Ni(OH)₂ constituted an asy-SCs device, which provided a specific capacitance of 89.6 F g⁻¹ after 5000 cycles. Wang et al. [174] prepared vanadium nitride hierarchical nanostructured electrodes on graphite foam (VN/GF) through an ammonia annealing procedure. The supercapacitive properties of nanostructured VN electrodes were measured by aqueous (KOH), organic (LiPF₆) electrolytes and neutral aqueous (LiCl) electrolyte. The capacitive energy storage of VN electrode showed 177, 90 and 154 C g⁻¹, in 1 M KOH, 1 M LiCl and 1 M LiPF₆, respectively at 50 mV s⁻¹, and presented the capacitive energy storage of LiPF6, and KOH electrolytes were closed to 74%, 70%, respectively (Fig. 12 f₁-f₆). The energy storage performance of prepared VN/C electrode in organic and alkaline electrolyte was superior to the neutral aqueous (LiCl) electrolyte. They explained that a small amount of VO_x and VN_xO_y were produced on the VN surface in neutral aqueous, However, In organic or neutral water system, the surface of VN electrode presenced of OH⁻. Furthermore We would like to further explain the energy storage mechanism of VN/C composite electrode.
一般來說，合成體系中的pH值，以及水體系、有機電解質和ILS等多種形式的電解質類型，在VN/C複合電極中都起著重要作用。例如，作者[56]報導了通過表面引發的原位插層聚合工藝，在不同pH值（0、1和2）下製備了新型雜化電極N摻雜碳納米片/氮化釩納米顆粒（N-CNS/VNNPs），分別被標記為N-CNS/VNNPs-0、N-CNS/VNNPs-1和N-CNS/VNNPs-2，發現碳納米片和VN納米顆粒的尺寸在納米尺度上隨著PH值從2降低到0而減小，導致N-CNS/VNNPs的比電容增加（在1 A g時高達280 F g ⁻¹ ）（圖12 d ₁ -d ₄ ，e）N-CNS/VNNPs電極和Ni（OH） ₂ 構成了一個asy-SCs器件，在5000次迴圈後提供89.6 F g ⁻¹ 的比電容。 ⁻¹ Wang等[174]通過氨退火工藝製備了泡沫石墨（VN/GF）上的氮化釩多級納米結構電極。通過水性（KOH）、有機（LiPF ₆ ）電解質和中性水性（LiCl）電解質測量了納米結構VN電極的超電容性能。在50 mV s ⁻¹ 時，VN電極在1 M KOH、1 M LiCl和1 M LiPF ₆ 中的電容儲能分別為177、90和154 C g，LiPF6 ⁻¹ 和KOH電解質的電容儲能分別接近74%和70%（圖12 f ₁ -f ₆ ）。 製備的VN/C電極在有機和鹼性電解質中的儲能性能優於中性水（LiCl）電解質。他們解釋說，在中性水溶液中，VN表面會產生少量的VO _x 和VN _x O _y ，然而，在有機或中性水體系中，VN電極表面存在OH ⁻ 。此外，我們還想進一步解釋VN/C複合電極的儲能機理。

In general, Trasatti's analysis [[241], [242], [243]] and Dunn analysis are used to study the energy storage mechanism of electrodes, Which mainly quantify capacitive contribution to the current response, while Dunn analysis is often used to study the energy storage mechanism of VN/C composite electrode. For example, Liu et al. [232] reported that an in-situ preparation for hybrid material of carbon nanosphere@vanadium nitride (CNS@VN) consisted of the precursor of metal-organic framework assembled by chitosan, NH4VO3 and F127. Whose structure was consist that porous carbon carbon was core, and nitrogen was shell (Fig. 12 g₁). The CNS@VN not only was confirmed the compositions of the hybrid electrode materials by SEM,TEM, XRD,TGA, but also was proven small content of electroactive substance in the electrode with high utilization rate. They calculated and identified fast capacitive storage mainly controlled the whole progress which the capacitive of contribution was about 72%, and the other part controlled by diffusion was about 28% (Fig. 12 g₂). Therefore, the core-shell CNS@VN electrode delivered the capacitance as high as 300.4 F g⁻¹,and had stable cycling stability with the retention rate of 70.8% and the coulombic efficiency of nearly 100% after 5000 cycles in 6 M KOH aqueous (Fig. 12 g₃).
一般採用Trasatti分析[[241]、[242]、[243]]和Dunn分析研究電極的儲能機理，主要量化電容對電流回應的貢獻，而Dunn分析常用於研究VN/C複合電極的儲能機理。例如，Liu等[232]報導了一種由殼聚糖組裝的金屬有機骨架前體NH4VO3和F127組成的碳nanosphere@vanadium氮化物（CNS@VN）雜化材料的原位製備。其結構由多孔碳為核心，氮為殼組成（圖12 g ₁ ）。該CNS@VN不僅通過SEM、TEM、XRD、TGA驗證了雜化電極材料的組成，而且證明瞭電極中電活性物質含量小，利用率高。他們計算並確定了快速電容存儲主要控制整個過程，貢獻電容約為72%，另一部分由擴散控制約為28%（圖12 g ₂ ）。因此，核殼CNS@VN電極在6 M KOH水溶液中迴圈5000次后，電容高達300.4 F g ⁻¹ ，迴圈穩定性穩定，保留率為70.8%，庫侖效率接近100%（圖12 g ₃ ）。

With the improvement of the performance requirements of intelligent electronic devices, various flexible wearable electronic devices have sprung up in our daily life. Flexible wearable electronic devices have the characteristics of light weight, easy to combine with skin, and withstand mechanical deformation [143]. For example, Guo et al. [233] reported that an exceptional electrode of vanadium nitride nanosheets/carbon nanotube fibers composite (VNNSs/CNTF) was obtained by Sol-thermal method and annealed process, and depicted a specific capacitance of 564 mF cm⁻² [233]. Furthermore, An outstanding mechanical flexibility hybrid SCs (FASC) (VN NSs/CNTF || ZNCO NWAs) was successfully fabricated with positive electrode of zinc-nickel-co ternary oxide (ZNCO) nanowire arrays (NWAs) and negative electrode of VN NSs/CNTF, respectively, which presented a maximum operating voltage of 1.6 V and maintained the capacitance of 91% after bending 3000 times at 90°. They explored a method to build a high energy density asy-SCs for future portable and wearable electronics. Moreover, A binder-free 3D VN nanowire array/carbon nanotube fibers composite (VN NWA/CNTF) electrode with an extraordinary specific capacitance of 715 mF cm⁻² was obtained by a facile and effective approach [143]. They fabricated a novel asymmetric coaxial fiber-shaped SCs (ACFSS) using VN NWA/CNTF as negative electrode with an exceptional specific capacitance of 213.5 mF cm⁻², an remarkable density of 96.07 μWh cm⁻², which has not been reported in FSS so far. The ACFSS device had excellent flexibility due to its electrochemical behavior remains almost unchanged and the capacitance retained 96.8% after bending 5000 times (Fig. 13 h₁,h₂). Therefore ACFSS will be woven into flexible electronic clothes with conventional weaving techniques. The reason why the equipment is good is The novel coaxial structure on one hand fully made full use of the effective surface area and reduced the contact resistance between the two electrodes, on the other hand provided a short pathway for the ultrafast transport of axial electrons and ions.
隨著智慧電子設備性能要求的提高，各種柔性可穿戴電子設備如雨後春筍般出現在我們的日常生活中。柔性可穿戴電子器件具有重量輕、易於與皮膚結合、耐機械變形等特點[143]。例如，Guo等[233]報導了氮化釩納米片/碳納米管纖維複合材料（VNNSs/CNTF）的特殊電極，採用溶膠熱法和退火工藝獲得，比電容為564 mF cm ⁻² [233]。此外，出色的機械柔性混合 SC （FASC） （VN NSs/CNTF ||ZNCO NWAs）成功製備了鋅鎳鈷三元氧化物（ZNCO）納米線陣列（NWAs）的正極和VN NSs/CNTF負極，最大工作電壓為1.6 V，在90°下彎曲3000次后仍能保持91%的電容。他們探索了一種為未來的攜帶型和可穿戴電子產品構建高能量密度 asy-SC 的方法。此外，通過一種簡單有效的方法獲得了一種無粘合劑的3D VN納米線陣列/碳納米管纖維複合材料（VN NWA/CNTF）電極，該電極具有715 mF cm ⁻² 的非凡比電容[143]。他們製造了一種新型的非對稱同軸光纖形狀SC（ACFSS），使用VN NWA/CNTF作為負極，具有213.5 mF cm ⁻² 的出色比電容，96.07 μWh cm ⁻² 的顯著密度，迄今為止尚未在FSS中報導。ACFSS器件具有出色的柔韌性，其電化學行為幾乎保持不變，彎曲5000次后電容保持率為96.8%（圖13 h ₁ ，h ₂ ）。 因此，ACFSS將採用傳統的編織技術編織成柔性電子服裝。設備之所以好，一方面是新穎的同軸結構充分利用了有效表面積，降低了兩個電極之間的接觸電阻，另一方面為軸向電子和離子的超快傳輸提供了一條短途路徑。

1. Download : Download high-res image (2MB)
   下載 ： 下載高解析度影像 （2MB）
2. Download : Download full-size image
   下載：下載全尺寸圖像

Fig. 13. (a) Schematic of the one-step (new method) and two-step (traditional method) synthesis process of two kinds of TiN@C NTs fiber electrode, (I and II), (b,c) Cross-sectional image of the TiN@C NTs II array, and TiN@C NTs I array (Inset shows the corresponding magnified image), (d) GCD Cycle time comparision of the TiN@C NTs I and II FSC, (e) Bent cycle stability of four different TiN@C NTs I and II FSCs, which demonstrates that the TiN@C NTs I FSCs are highly bending resistant due to significantly improved mechanical stability. Inset photo shows the bending cycle operation from 0° to 360° [50]. Copyright 2018 Elsevier. (f) Schematic of hydrothermal and layer by layer method, (g) DFT simulations of MoN@P-CF, (h) The plot of capacitance retention with cycle number over 15,000 cycles measured, inset shows the first and last charge-discharge cycles. (i) Practical demonstration of MoN@P-CF||RuO₂@CF SCs [248]. Copyright 2018 Elsevier.
圖 13.（a）兩種TiN@C NTs光纖電極（I和II）的一步法（新方法）和兩步法（傳統法）合成過程示意圖，（b，c）TiN@C NTs II陣列和TiN@C NTs I陣列的截面圖（插圖為相應的放大圖像），（d）TiN@C NTs I和II FSC的GCD循環時間比較， （e） 四種不同TiN@C NTs I和II FSC的彎曲循環穩定性，表明TiN@C NTs I FSC由於機械穩定性顯著提高而具有很強的抗彎曲性。插圖顯示了從0°到360°的彎曲迴圈操作[50]。版權所有 2018 Elsevier。（f）熱液示意圖和逐層方法，（g）MoN@P-CF的DFT類比，（h）測量的迴圈次數超過15,000次迴圈的電容保持圖，插圖顯示了第一次和最後一次充放電迴圈。（i） MoN@P-CF||RuO ₂ @CF SCs[248]。版權所有 2018 Elsevier。

In short, VN/C composite electrodes often exhibit high electrochemical performance containing excellent specific capacitance, exceptional cycling stability and rate capability and outstanding energy density and power density, due to the synergic effect of the two components. Even so, we should seek better electrode materials and expand the field of SCs.
總之，VN/C複合電極通常具有較高的電化學性能，具有優異的比電容、優異的循環穩定性和倍率能力以及出色的能量密度和功率密度，這是由於兩種組分的協同作用。即便如此，我們還是應該尋求更好的電極材料，擴大SCs的領域。

4.2. TiN/C 4.2. TiN/C（英語：TiN/C）

As mentioned above, in order to maintain high energy density and improve power density, TiN/C nanocomposites electrode with excellent electrochemical properties are usually synthesized by combination of nanostructured carbon materials with high surface area and adjustable pore size and titanium nitride with high conductivity. Lu et al. [170] reported the growth of independent TiN nanowires (NWs) on carbon cloth (TiN NWs/C) via a two-step process. A high volumetric specific capacitance of 0.33 F cm⁻³ at a current density of 2.5 mA cm⁻³ was comparable to the values recently reported for solid-state graphene-based SCs (0.42 F cm⁻³, PVA/H₃PO₄), while the as fabricated TiN NWs/C electrode exhibited an initial capacitance of 82% after 15, 000 cycles in 1 M KOH electrolyte solution.
如上所述，為了保持高能量密度和提高功率密度，通常將高表面積和可調孔徑的納米結構碳材料與高導電率的氮化鈦相結合，合成了具有優異電化學性能的TiN/C納米複合材料電極。Lu等[170]報導了碳布（TiN NWs/C）上獨立TiN納米線（NWs）的生長過程。在2.5 mA cm的電流密度下，0.33 F cm ⁻³ 的高體積比電容與最近報導的固態石墨烯基SCs（0.42 F cm，PVA ⁻³ /H ₃ PO ₄ ）的值相當，而製造的TiN NWs/C電極在1 M KOH電解質溶液中迴圈15， 000次後表現出82%的初始電容。 ⁻³

CNTs meterials exhibited the electron transfer properties superior to other materials and were considered to be excellent conductive Material. In recent years, many TiN/CNT composite electrodes for SCs have been reported. Such as Achour et al. [182] reported that a TiN/CNTs composite eletrode deposited of TiN on vertically aligned CNTs by reactive DC sputtering. The capacitance of TiN/CNTs (18.3 mF cm⁻²) with multi-faceted nanostructures and porous structure presented 360 times higher than CNT as electrode in neutral electrolyte. They suggested that the mechanism of excellent storage charge was due to the high surface area of electrode, the existence of oxygen vacancies on electrode surface (contribution of pseudocapacitance). Moreover they showed that doping N on the surface of TiO₂ with the substitution of N in the surface layer of anatase-type TiO₂ during synthesis and aging can increase the concentration of oxygen vacancies which resulting in increasing the capacitance of SCs. In addition, compared with EDLC electrode, the capacitance of the prepared electrode with the thick of 1200 nm was much higher than that of AC eletrode (0.4 mF cm⁻² at 100 mV s⁻¹) [244], CNT carpet (0.11 mF cm⁻² at 100 mV s⁻¹) [245,246], and nanoporous carbon-based MSCs (6.7 mF cm⁻²). Sun et al. [50] reported that the titanium nitride and carbon nanotubes (TiN@C NTs) based fiber electrodes were prepared by a single-step nitridation and all-carbon coating process (two-step method) (Fig. 13 a), The SEM image of TiN@C NTs II and TiN@C NTs (Fig. 13b and c). The prepared TiN@C NTs presented outstanding conductive contact between active materials and the substrate, acquired a high specific capacitance of 19.4 mF cm⁻² at a scan rate of 10 mV s⁻¹ which exhibit 260% higher capacitance than the samples achieved by traditional two-step nitridation and carbonization method (Fig. 13 d). A long cycling test of TiN@C NTs flexible SCs exhibited excellent cycling stability over 20,000 consecutive cycles with 10% decay in capacitance (Fig. 13 e). Therefor, TiN@C NTs meterials can also be used as electric cable for current transfer while storing energy simultaneously, which broadens the applications of this new type FSC.
碳納米管材料的電子轉移性能優於其他材料，被認為是優良的導電材料。近年來，許多用於SC的TiN/CNT複合電極已被報導。如Achour等[182]報導，TiN/CNTs複合材料通過反應直流濺射將TiN沉積在垂直排列的CNT上。具有多面納米結構和多孔結構的TiN/CNTs（18.3 mF cm ⁻² ）的電容比CNT在中性電解質中的電極高360倍。他們認為，優異的存儲電荷的機制是由於電極的高表面積，電極表面存在氧空位（贗電容的貢獻）。此外，他們表明，在合成和老化過程中，在銳 ₂ 鈦礦型TiO表面摻雜N並取代銳鈦礦型TiO ₂ 表層中的N可以增加氧空位的濃度，從而增加SCs的電容。此外，與EDLC電極相比，厚度為1200 nm的電極的電容遠高於AC eletrode （0.4 mF cm ⁻² at 100 mV s ⁻¹ ） [244]、CNT地毯 （0.11 mF cm ⁻² at 100 mV s ⁻¹ ） [245,246] 和納米多孔碳基間充質幹細胞 （6.7 mF cm ⁻² ） 。Sun等[50]報導了氮化鈦和碳納米管（TiN@C NTs）基纖維電極採用單步氮化和全碳塗層工藝（兩步法）（圖13a），TiN@C NTs II和TiN@C NTs的SEM圖像（圖13b和c）。製備的TiN@C NTs在活性材料與基板之間具有出色的導電接觸性，比電容高達19。在10 mV s ⁻¹ 的掃描速率下，4 mF cm ⁻² ，其電容比傳統的兩步氮化和碳化方法實現的樣品高260%（圖13 d）。對 TiN@C NTs 柔性 SC 進行長時間循環測試，在 20,000 次連續迴圈中表現出出色的迴圈穩定性，電容衰減 10%（圖 13 e）。因此，TiN@C NTs材料還可以用作電力電纜，在同時存儲能量的同時進行電流傳輸，這拓寬了這種新型FSC的應用範圍。

4.3. Mo_xN/C 4.3. _x 鉬常閉

Molybdenum nitride (MoN) has superior pseudocapacitive behavior and able to applied in the negative potential window, which makes it promising compounded with the carbon materials with large specific surface area [247,249]. Impressively, Dubal and Abdel-Azeim et al. [248] reported the design of MoN nanoparticle electrodes with enhanced ionic affinity and thermodynamic stability on phosphorus-bonded carbon fabric (MoN@P-CF) (Fig. 13 f). MoN@P-CF nanocomposites improved the redox kinetics of the electrode surface, resulted in providing an extraordinary pseudocapacitance of 400 mF cm⁻² (twice as high as that of molybdenum nitride) and possessing a fast charging/discharging speed. Density functional theory (DFT) simulation was established to explain the good proton affinity and electrochemical performance of MoN@P-CF in proton-based water electrolytes (Fig. 13 g). With MoN@P-CF as negative electrode and RuO₂ as positive electrode (Fig. 13 i), all pseudocapacitive solid-state asy-SCs was assembled. A long cycling test presented excellent specific capacitance energy density and power densities of 7.74 Fcm⁻³, 2.4 mWhcm⁻³and 174 mWcm⁻³ respectively and over 15,000 consecutive cycles with good cycling stability of 89% in capacitance (Fig. 13 h).
氮化鉬（MoN）具有優異的贗電容性能，能夠施加在負電位視窗內，這使得它有望與具有大比表面積的碳材料複合[247,249]。令人印象深刻的是，Dubal和Abdel-Azeim等[248]報導了MoN納米顆粒電極的設計，該電極在磷鍵碳織物（MoN@P-CF）上具有增強的離子親和力和熱力學穩定性（圖13 f）。MoN@P-CF納米複合材料改善了電極表面的氧化還原動力學，提供了400 mF cm ⁻² （是氮化鉬的兩倍）的非凡贗電容，並具有快速的充放電速度。建立了密度泛函理論（DFT）類比，解釋了MoN@P-CF在質子基水電解質中良好的質子親和力和電化學性能（圖13 g）。以MoN@P-CF為負極，RuO ₂ 為正極（圖13 i），組裝了所有贗電容固態ASY-SC。在長時間的循環測試中，比電容能量密度和功率密度分別為7.74 Fcm ⁻³ 、2.4 mWhcm ⁻³ 和174 mWcm ⁻³ ，連續迴圈超過15,000次，電容循環穩定性良好，達到89%（圖13 h）。

4.4. Fe₂N/C 4.4. 鐵 ₂ 常閉

Among various TMN, Fe₂N was recognized as the best pseudocapacitence electrode material [250] due to its good conductivity, low cost, low electrical resistance and friendly environment. Xu et al. reported that [251] a series of new iron nitride (Fe₂N)/cubic ordered mesoporous carbon (OMC) composites (Fe₂N@OMC) were synthesized by a simple nano-casting process and ammonia calcination (Fig. 14), CV measurement depicted a specific capacitance of 547 F g⁻¹ at 1 mV s⁻¹ with Fe₂O₃ content of 57.6 at.%, and the content of Fe₂N of 40.3 at.%, cycles, exhibited the specific capacitance retention of 85% along with after 1000, which was much higher than that of bare Fe₂N by 28%.
在各種TMN中，Fe ₂ N因其導電性好、成本低、電阻低、環境友好而被公認為最好的贗電容電極材料[250]。Xu等報導[251]通過簡單的納米鑄造工藝和氨煆燒合成了一系列新型氮化鐵（Fe ₂ N）/立方有序介孔碳（OMC）複合材料（Fe ₂ N@OMC），CV測量顯示，在1 mV s ⁻¹ 時，比電容為547 F g，Fe ₂ ⁻¹ O ₃ 含量為57.6 at.%，Fe ₂ N為40.3 at.%，迴圈次數為1000%后，比電容保持率為85%，比裸Fe ₂ N高出28%。

1. Download : Download high-res image (293KB)
   下載 ： 下載高解析度圖片 （293KB）
2. Download : Download full-size image
   下載：下載全尺寸圖像

Fig. 14. Illustration of Fe₂N@OMC composite synthesis by nano-casting technology and ammonia calcination [251]. Copyright 2017 Royal Society of Chemistry.
圖 14.利用納米鑄造技術和氨煆燒合成Fe ₂ N@OMC複合材料[251]。版權所有 2017 英國皇家化學學會。

4.5. NbN/C

Compared with other TMN NbN particles not only played the role of electrodes, but also played the role of organizing graphene condensation, so as to improve the effect of energy storage composite materials [199] Niobium nitride/nitrogen‐doped graphene nanosheet hybrid electrode (NbN/NG) was prepared by a facial hydrothermal combined with ammonia annealing method, and attained high capacitance retention of 81.7% after 1000 cycles at a current density of 500 mA g⁻¹ [252] However, Nb₄N₅ with high oxidation state delivered a high capacitance of 225.8 mF cm⁻², along with capacitance retention of 70.9% after 2000 cycles. The main reason was that faradaic pseudocapacitance was produced by the proton incorporation/chemisorption reaction and was the source of abundant +5 valence Nb ions in Nb₄N₅ [253].
與其他TMN相比，NbN顆粒不僅起到了電極的作用，而且起到了組織石墨烯縮合的作用，從而提高了儲能複合材料的效果[199]，採用面熱結合氨退火法制備了氮化鈮/氮摻雜石墨烯納米片雜化電極（NbN/NG），在500 mA g ⁻¹ 的電流密度下，經過1000次迴圈后，電容保持率高達81.7%[252] 然而， 高氧化態的Nb ₄ N ₅ 在2000次迴圈后提供了225.8 mF cm ⁻² 的高電容，電容保持率為70.9%。主要原因是法拉第贗電容是由質子摻入/化學吸附反應產生的，並且是Nb ₄ N ₅ 中豐富的+5價Nb離子的來源[253]。

4.6. Other TMN/C 4.6. 其他TMN/C

In recent years, Apart from VN/C, TiN/C, MoN/C and Fe₂N/C composites, many other TMN composites have been reported and also exhibit excellent electrochemical performance. Dans et al. [92] reported that the cobalt nitride (CoN) with the particles sizes of 20–30 nm was prepared under NH₃ and N₂ atmosphere at low temperature. Cyclic voltammetry and constant current cadmium method were used to study the electrochemical behaviour of the CoN electrode in nonaqueous electrolyte (1 M LiPF₆ dissolved in ethylene carbonate (EC) +dimethyl carbonate (DMC)). The electrochemical performance of the CoN/AC electrode provided a specific capacitance of 37 F g⁻¹, circulating at 30 mA g⁻¹. Balogun et al. [254] reported that a 3D nickel nitride (3D Ni₃N) on carbon cloth elctrode was prepared by simple hydrothermal and post-annealing process, which exhibited the capacitance of 900 F g⁻¹ at 10 mA cm⁻² and depicted a capacitance retention of 81% at 40 mA cm⁻² in 1 M KOH aqueous solution.
近年來，除了VN/C、TiN/C、MoN/C和Fe ₂ N/C複合材料外，還報導了許多其他TMN複合材料，它們也表現出優異的電化學性能。Dans等[92]報導了粒徑為20–30 nm的氮化鈷（CoN）是在 ₃ NH和N ₂ 氣氛下低溫製備的。採用迴圈伏安法和恆流鎘法研究了CoN電極在非水電解質（1 M LiPF ₆ 溶於碳酸乙烯酯（EC）+碳酸二甲酯（DMC）中）中的電化學行為。CoN/AC電極的電化學性能提供了37 F g ⁻¹ 的比電容，迴圈電容為30 mA g ⁻¹ 。Balogun等[254]報導，通過簡單的水熱和後退火工藝製備了碳布上的3D氮化鎳（3D ₃ Ni N），在10 mA cm ⁻² 時表現出900 F g ⁻¹ 的電容，在1 M KOH水溶液中，40 mA cm ⁻² 處的電容保持率為81%。

In short, the most advanced examples revealed the synergistic effects of TMN/C. Combining TMN with carbon materials was one of the most attractive methods to improve the specific capacitance and energy density of SCs and overcome the limitation of single TMN on SCs application.
總之，TMN/C的協同效應得到了體現，TMN與碳材料的結合是提高SCs比電容和能量密度，克服單一TMNs在SCs應用上的局限性的最有吸引力的方法之一。