Three-dimensional Ni0.85Se@ZnSe nanostructures on carbon cloth for flexible asymmetric battery-type supercapacitors

Abstract

Metal selenides and their derivatives have attracted great attention and are regarded as promising electrode materials due to their superior electrochemical activity and conductivity. Therefore, we design a facile one-step electrodeposition method to produce Ni_0.85Se@ZnSe nanostructures assembled from ultrathin nanosheets on carbon cloth (CC). The unique three-dimensional (3D) heterostructure and synergistic effect between Ni_0.85Se and ZnSe give the electrode superior electrochemical performance. The specific capacity of the optimized Ni_0.85Se@ZnSe CC electrode can reach 1927 F g⁻¹ at 1 A g⁻¹ and also displays good rate performance. An asymmetric supercapacitor (ASC) device, Ni_0.85Se@ZnSe-10//AC, was assembled and tested, exhibiting a higher energy density of 74.67 W h kg⁻¹ at a power density of 800 W kg⁻¹, and good cycling stability. The results show that the Ni_0.85Se@ZnSe nanocomposite has extremely high performance as an electrode for supercapacitors, which further provides a new strategy for the design of high-performance bimetallic selenide electrode materials in the field of energy storage.