Hollow core–shell CuCo2O4@MoNi-layered double hydroxides as an electrode material for supercapacitors

Abstract

This paper presents CuCo2O4@MoNi-layered double hydroxides (CuCo2O4@MoNi-LDH) core–shell assemblies synthesized successfully by a stepwise process using hydrothermal and calcination methods. The morphology of a core–shell structure consisting of nanosheets grown uniformly on the surface of the hollow spheres was realized. The results showed that CuCo2O4@MoNi-LDH hollow spherical nano-sheets are an excellent choice for applications that require outstanding structural stability and a high specific surface area. A specific capacitance of 1286 F g−1 was obtained at a current density of 1 A g−1, which indicates its promising application in supercapacitors. Furthermore, asymmetric supercapacitors assembled using CuCo2O4@MoNi-LDH positive electrodes achieved an ultra-high strength density of 68.1 Wh kg−1 at an energy density of 795.9 W kg−1 with an excellent cycling stability (i.e., the capacitance retention rate of 88 % after 6000 cycles). According to these findings, CuCo2O4@MoNi-LDH is a strong contender for power storage applications.