Transition metal borides have shown great promise as a supercapacitor electrode material. However, the amorphous structure of metal borides leads to the structural collapse of electrode material during electrochemical cycling, which seriously affects the stability of the material. In the present work, we successfully construct amorphous/crystalline NiCoB@NiCo2S4 heterogeneous interfacial composites by introducing the outer layer of sulfide to improve the electrochemical performance. NiCoB@NiCo2S4 shows a specific capacitance of 1562 F g−1 at a current density of 1 A g−1 and still possesses 58% specific capacitance even at a higher current density of 50 A g−1. The asymmetric supercapacitor (ASC) device assembled with Bi2O3@C as the negative electrode and NiCoB@NiCo2S4 as the positive exhibits a high energy density of 98.75 Wh kg−1 at a power density of 750 W kg−1. The ASC also exhibits excellent cycling stability with capacitance retention of 118% after 10000 cycles at a current density of 10 A g−1, which fully demonstrates the practical applications value of NiCoB@NiCo2S4//Bi2O3@C.

中文翻译：

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非晶/晶NiCoB@NiCo2S4异质界面纳米复合材料的简单结构，以增强超级电容器的性能


过渡金属硼化物作为超级电容器电极材料已显示出巨大的前景。然而，金属硼化物的非晶结构导致电极材料在电化学循环过程中结构塌陷，严重影响材料的稳定性。在本工作中，我们通过引入硫化物外层来改善电化学性能，成功地构建了非晶/结晶NiCoB@NiCo2S4非均相界面复合材料。NiCoB@NiCo2S4在 1 A g-1 的电流密度下显示出 1562 F g-1 的比电容，即使在 50 A g-1 的较高电流密度下，仍然具有 58% 的比电容。以 Bi2O3@C 作为负极，NiCoB@NiCo2S4 作为正极组装的非对称超级电容器 （ASC） 器件在 750 W kg-1 的功率密度下表现出 98.75 Wh kg-1 的高能量密度。ASC 还表现出优异的循环稳定性，在 10 A g−1 的电流密度下，经过 10000 次循环后，电容保持率为 118%，这充分证明了 NiCoB@NiCo2S4//Bi2O3@C 的实际应用价值。