With excellent physico-chemical properties such as conducive crystal structures, pseudocapacitance, and metallic conductivity, tungsten nitride (WN) can be an attractive electrode material for supercapacitors but is restricted by its inferior intrinsic reaction activity. Herein, the energy harvestability of WN nanowires is significantly enhanced through a low-dose isovalent Co doping due to the synergistic effect between highly symmetric crystal octahedral structures and dopants. The difference in the number of d orbital electrons of Co³⁺ and W³⁺ can induce Jahn–Teller distortion in the local structure, enhancing the crystal/electron structure regulation ability. The Co dopants can capture electrons from W ions due to their lower electronegativity and act as highly active sites that participate in the energy storage process, improving the rate capability and reversible capacitance. When adopted as the electrode, the optimized Co-doped WN nanowires (Co-doped WN@CC, 3418.4 mF cm⁻²) can deliver a 9 times higher capacitance than the pure WN electrode (WN@CC, 379 mF cm⁻²) at 4 mA cm⁻², and can steadily work for 10 000 continuous cycles. The full device that uses polypyrrole (PPy) as the counter electrode exhibits an intriguing energy density (108.33 μW h cm⁻²) at a high power density of 5.2 mW cm⁻². Our work may inspire the development of rational cationic doping for advanced electrodes.

中文翻译：

---

通过八面体结构和等价离子掺杂之间的协同作用实现非凡增强的可逆电容

氮化钨 (WN) 具有优异的物理化学性质，如导电晶体结构、赝电容和金属导电性，可以成为超级电容器的一种有吸引力的电极材料，但受限于其较差的本征反应活性。在此，由于高度对称的晶体八面体结构和掺杂剂之间的协同效应，通过低剂量等价 Co 掺杂显着增强了 WN 纳米线的能量收集能力。^{Co 3+}和W ³⁺的d轨道电子数的差异可以引起局部结构的Jahn-Teller畸变，增强晶体/电子结构调节能力。由于其较低的电负性，Co 掺杂剂可以从 W 离子中捕获电子，并充当参与能量存储过程的高活性位点，从而提高倍率性能和可逆电容。当用作电极时，优化的 Co 掺杂 WN 纳米线（Co 掺杂 WN@CC，3418.4 mF cm ^{-2 ）可以提供比纯 WN 电极（WN@CC，379 mF cm -2}）高 9 倍的电容在 4 mA cm ^-2下，可稳定工作 10 000 次连续循环。使用聚吡咯 (PPy) 作为对电极的完整器件表现出有趣的能量密度 (108.33 μW h cm ^{-2) 在 5.2 mW cm -2}的高功率密度下。我们的工作可能会激发先进电极的合理阳离子掺杂的发展。