Zinc-ion hybrid supercapacitors (ZHSCs) are considered to be a promising and safe energy storage system. The design of carbon-based cathode materials is crucial to improving the performance of ZHSCs. In this work, a nitrogen-doped porous carbon fiber (NPCE) was prepared by a combination of template and etching methods, which could directly serve as the cathode for ZHSCs. The ion transfer channel was adjusted by rationally controlling the amount of ZnO template agent, which enhanced ion transfer and increased the capacitive contribution. The pyrolysis of polyacrylonitrile as carbon and nitrogen resources provided rich nitrogen functional groups for charge storage. In a 2 M ZnSO₄ electrolyte, the optimized NPCE-4 exhibited superior electrochemical performance with a capacitance of 283.9 F g^–1 at a current density of 1 mA cm^–2. The ZHSC achieved an energy density of 101 Wh kg^–1 at a power density of 457 W kg^–1, along with excellent cycle life with a capacity retention rate of 98.9% at 20 mA cm^–2 after 10 000 cycles.

中文翻译：

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氮掺杂多孔碳纤维作为用于增压锌离子混合超级电容器的自支撑电极


锌离子混合超级电容器 （ZZHSC） 被认为是一种有前途且安全的储能系统。碳基正极材料的设计对于提高 ZHSC 的性能至关重要。本工作采用模板和刻蚀相结合的方法制备了氮掺杂多孔碳纤维 （NPCE），可直接作为 ZHSCs 的阴极。通过合理控制 ZnO 模板剂的用量来调整离子转移通道，从而增强离子转移并增加电容贡献。聚丙烯腈作为碳和氮资源的热解为电荷储存提供了丰富的氮官能团。在 2 M ZnSO₄ 电解质中，优化的 NPCE-4 表现出优异的电化学性能，在 1 mA cm^–2 的电流密度下电容为 283.9 F g^–1。ZHSC 在 457 W ^kg-1 的功率密度下实现了 101 Wh ^kg-1 的能量密度，并且具有出色的循环寿命，在 10 000 次循环后，在 20 mA ^cm-2 时的容量保持率为 98.9%。