Optimizing the charge transfer process by designing Co3O4@PPy@MnO2 ternary core–shell composite

Abstract

In this paper, the incorporation of a highly conductive material (polypyrrole) into a binary metal-oxide core–shell structured composite is adopted to optimize the charge transfer process to further improve electrochemical performance. Because of enhanced electron transfer capability, charge transfer resistances of the ternary core–shell structured composites are reduced and the electrochemical performances are improved. For example, the Co₃O₄@PPy@MnO₂ ternary core–shell heterostructured composite exhibits high specific capacitance and excellent rate capability (53% of capacity retention rate at 40 A g⁻¹ compared with 782 F g⁻¹ at 0.5 A g⁻¹). The composite shows good cycling stability with 97.6% capacity retention over 2000 cycles at 5 A g⁻¹. These results demonstrate the potential of core–shell composites to further improve the performance in supercapacitor electrodes.