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

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 Ni0.85Se@ZnSe nanostructures assembled from ultrathin nanosheets on carbon cloth (CC). The unique three-dimensional (3D) heterostructure and synergistic effect between Ni0.85Se and ZnSe give the electrode superior electrochemical performance. The specific capacity of the optimized Ni0.85Se@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, Ni0.85Se@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 Ni0.85Se@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.