Ternary cobalt nickel sulfides are considered promising electrode materials due to their unique physical properties. However, its capacitive performance is still limited by the insufficient material utilization efficiency. Here, we design and fabricate CoNi₂S₄ with nanorods and hairy-petal-like nanosheets on nickel foam (NF) as an excellent self-standing electrode for a hybrid supercapacitor (HSC). The CoNi₂S₄ electrode material was synthesized on the NF substrate by cobalt organic framework (Co-MOF) conversion and introducing sulfur ion and nickel ion exchange. The CoNi₂S₄ electrode material with sulfur vacancies was controlled by regulating the reduction time, and then electrochemical analysis and comparison were performed. The results demonstrate that the synergistic effect of the MOF-derived CoNi₂S₄ skeleton and sulfur vacancies can significantly improve the electrochemical activity of nickel cobalt sulfide. The CoNi₂S₄ electrode exhibits a superior high specific capacitance of 5.24 F/cm² at a current density of 3 mA/cm². Furthermore, the assembled CoNi₂S₄-60//AC HSC displays a high energy density of 59.41 Wh/kg and a power density of 999.98 W/kg. Even after 10,000 continuous charge–discharge cycles, its initial capacitance was retained at 89.24%. These results demonstrate the feasibility and practicality of CoNi₂S₄-60 as an electrode material, showcasing its potential for real-world applications.

中文翻译：

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CoNi2S4 空位硫位对其在混合超级电容器中电化学性能的影响


三元钴镍硫化物由于其独特的物理性质而被认为是有前途的电极材料。然而，其电容性能仍然受到材料利用效率不足的限制。在这里，我们在泡沫镍 （NF） 上设计和制造了带有纳米棒和毛状花瓣状纳米片的 CoNi₂S₄，作为混合超级电容器 （HSC） 的优秀自立式电极。通过钴有机框架 （Co-MOF） 转化并引入硫离子和镍离子交换，在 NF 衬底上合成了 CoNi₂S₄ 电极材料。通过调节还原时间来控制具有硫空位的 CoNi₂S₄ 电极材料，然后进行电化学分析和比较。结果表明，MOF 衍生的 CoNi₂S₄ 骨架和硫空位的协同作用可以显着提高镍钴硫化物的电化学活性。CoNi₂S₄ 电极在 3 mA/cm² 的电流密度下表现出 5.24 F/cm² 的优异高比电容。此外，组装好的 CoNi₂S_4-60//AC HSC 显示出 59.41 Wh/kg 的高能量密度和 999.98 W/kg 的功率密度。即使经过 10,000 次连续充放电循环后，其初始电容仍保持在 89.24%。这些结果证明了 CoNi₂S 4-60 作为电极材料的可行性和实用性，展示了其在实际应用中的潜力。