Preparation of MgCo2O4@NiCo2S4 core-shell nanocomposites for high-performance asymmetric supercapacitors

The MgCo2O4@NiCo2S4 core-shell structure was prepared using hydrothermal and annealing methods. The synergy between MgCo2O4 nanoneedles and NiCo2S4 nanosheets is beneficial to improved electronic transmission capability. In this experiment, the specific capacity of MgCo2O4@NiCo2S4 can reach 1255.1 C g−1 at 1 A g−1. And it shows good capacity performance and cycling stability (78.07% after 2000 cycles). An asymmetric supercapacitor (ASC) was designed using MgCo2O4@NiCo2S4 and activated carbon (AC) as electrode materials. It has an excellent cycle stability of 83.2% after 5000 cycles. Meanwhile, the ASC shows a remarkable energy density of 111.26 Wh kg−1 at 800.4 W kg−1. In conclusion, MgCo2O4@NiCo2S4 is very promising as an energy storage material.