A facile synthesis of Ni0.85Se@Cu2−xSe nanorods as high-performance supercapacitor electrode materials

Abstract

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).