ZnCo_O_4@MnCo_2O_4 heterojunction structured nanosheets for high- performance supercapacitor

摘要

Abstract ZnCo~(2)O~(4)@MnCo~(2)O~(4)heterojunction structured nanosheets were successfully prepared by simple and effective hydrothermal reaction. The obtained heterojunction structured had large specific surface area, good structural stability, and excellent electrical conductivity. Therefore, they were expected to become ideal electrochemical materials. As expected, a series of electrochemical tests showed ZnCo~(2)O~(4)@MnCo~(2)O~(4)heterojunction structured nanosheets demonstrate high specific capacitance (254 F g_(−1)at the current density of 1 A g_(−1)). Good stability of charge–discharge, when the current density was 10 A g_(−1), the capacity can still maintain 186 F g_(−1). Especially, the maximum energy density of asymmetric supercapacitors based on ZnCo~(2)O~(4)@MnCo~(2)O~(4)and activated carbon at 750 W Kg_(−1)was 19.12 Wh Kg_(−1), and the cycle stability was good, after 2000 cycles, the capacitance retention rate was 98.5%. For practice application, the commercial LED lights can be lighted by two supercapacitor units in series. It shows that the synthetic electrode material has great potential in the energy storage equipment.