Abstract We synthesized NiCo2S4@rGO for electrode applications using a facile one-step solvothermal method. NiCo2S4@rGO exhibited excellent electrochemical activity due to abundance of active sites and had a higher capacitance than other unitary metal oxides or sulfides. The synthesized electrode achieved a specific capacitance of 2418 F g−1 at a current density of 1 A g−1. In the asymmetric supercapacitor, NiCo2S4@rGO and N-doped graphene are used as the cathode and anode, respectively, and an extended potential working window of 1.6 V can be obtained. A combination of pseudocapacitance and double layer capacitance resulted in NiCo2S4@rGO achieving good rate performance and excellent cyclic stability. The device delivered a maximum energy density of 34.1 Wh kg−1 at a power density of 411 W kg−1. In addition, the device possessed acceptable cyclic stability, with 86.4% capacitance retention after 5000 cycles. The proposed method provides a general route for assembling supercapacitors with high capacitance and wide voltage window.

中文翻译：

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在石墨烯上原位生长的镍钴硫化物纳米粒子的设计和构建具有增强的非对称超级电容器性能

摘要 我们使用简便的一步溶剂热法合成了用于电极应用的 NiCo2S4@rGO。NiCo2S4@rGO 具有丰富的活性位点，表现出优异的电化学活性，并且比其他单一金属氧化物或硫化物具有更高的电容。合成电极在 1 A g-1 的电流密度下实现了 2418 F g-1 的比电容。在非对称超级电容器中，NiCo2S4@rGO 和 N 掺杂的石墨烯分别用作阴极和阳极，可以获得 1.6 V 的扩展电位工作窗口。赝电容和双层电容的结合使 NiCo2S4@rGO 实现了良好的倍率性能和优异的循环稳定性。该器件在 411 W kg-1 的功率密度下提供了 34.1 Wh kg-1 的最大能量密度。此外，该器件具有可接受的循环稳定性，5000 次循环后电容保持率为 86.4%。所提出的方法为组装具有高电容和宽电压窗口的超级电容器提供了一般途径。