Abstract In this work, we have developed a sequential chemically topotactic transformation strategy to fabricate highly porous thin NiCo2S4 discs with complex crisscross pore channels through sequential in situ ion-exchange. Starting from Co3O4 discs prepared by direct pyrolysis of solid Co-glycolate discs, complex porous Co3S4 and NiCo2S4 discs are obtained after the sequential ion-exchange reactions with S2− and Ni2+ ions, respectively. Physicochemical and electrochemical investigations demonstrate that the as-derived NiCo2S4 discs with high electrical conductivity, ion-diffusion-derived large accessible surface area and pore volume present attractive pseudocapacitive properties including remarkably high capacitivity (908 F g−1 at 3 A g−1), good rate capability (610 F g−1 at 20 A g−1) and outstanding electrochemical stability with a capacitance retention of 82% after continuous cycling for 5000 cycles. Furthermore, a hybrid device using the NiCo2S4 discs and carbon-based composite as positive and negative electrodes, respectively, delivers a high energy density of 42.7 Wh kg−1 at a power density of 375 W kg−1, suggesting that the NiCo2S4 discs could be a powerful electrode platform for advanced supercapacitors.

中文翻译：

---

通过顺序离子交换形成具有增强赝电容特性的高多孔 NiCo 2 S 4 圆盘

摘要 在这项工作中，我们开发了一种顺序化学拓扑转化策略，通过顺序原位离子交换制备具有复杂纵横交错孔道的高多孔薄 NiCo2S4 圆盘。从通过固体 Co-乙醇酸盘直接热解制备的 Co3O4 盘开始，分别与 S2- 和 Ni2+ 离子进行顺序离子交换反应后获得复杂的多孔 Co3S4 和 NiCo2S4 盘。物理化学和电化学研究表明，具有高导电性、离子扩散衍生的大可及表面积和孔体积的衍生 NiCo2S4 圆盘呈现出有吸引力的赝电容特性，包括非常高的电容（908 F g-1 at 3 A g-1） , 良好的倍率性能（20 A g-1 时为 610 F g-1）和出色的电化学稳定性，连续循环 5000 次循环后电容保持率为 82%。此外，分别使用 NiCo2S4 圆盘和碳基复合材料作为正极和负极的混合装置在 375 W kg-1 的功率密度下提供 42.7 Wh kg-1 的高能量密度，表明 NiCo2S4 圆盘可以成为先进超级电容器的强大电极平台。