Transition-metal selenides are regarded as promising electrode materials due to their superior electrochemical performances for supercapacitors. In this study, a nanorod-like hybrid of Ni_0.85Se@Cu_2−xSe on a Ni-foam substrate is successfully synthesized via a facile one-step route. The Ni_0.85Se@Cu_2−xSe nanorods are found to be deposited uniformly on the Ni-form substrates. When used as a battery-type electrode in a supercapacitor, the as-deposited Ni_0.85Se@Cu_2−xSe electrode exhibits a high specific capacity of 1831 F g⁻¹ at 1 A g⁻¹ and 78.4% of capacitance retention after 8000 cycles at 10 A g⁻¹. Moreover, the assembled Ni_0.85Se@Cu_2−xSe//AC asymmetric supercapacitor (ASC) exhibits an energy density of 63.2 W h kg⁻¹ at a power density of 800.1 W kg⁻¹, as well as good cycling stability (92.1% capacitance retention after 5000 cycles).

中文翻译：

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Ni0.85Se@Cu2−xSe纳米棒作为高性能超级电容器电极材料的简便合成

过渡金属硒化物因其优异的超级电容器电化学性能而被认为是有前景的电极材料。在这项研究中，通过简单的一步法成功地合成了 Ni _0.85 Se@Cu _{2- x} Se 在 Ni 泡沫基材上的纳米棒状混合物。发现 Ni _0.85 Se@Cu _{2- x} Se 纳米棒均匀地沉积在 Ni 型基底上。当用作超级电容器中的电池型电极时，沉积态的 Ni _0.85 Se@Cu _{2- x} Se 电极在 1 A g ^{-1 下}表现出 1831 F g ^-1的高比容量10 A g ^{-1 下}8000 次循环后的电容保持率为 78.4% 。此外，组装的Ni _0.85 Se@Cu _{2- x} Se//AC不对称超级电容器（ASC）在800.1 W kg ^-1的功率密度下表现出63.2 W h kg ^-1的能量密度，以及良好的循环稳定性（ 5000 次循环后 92.1% 的电容保持率）。