Asymmetric Supercapacitors Based on Co3O4@MnO2@PPy Porous Pattern Core-Shell Structure Cathode Materials

Abstract

In recent years, supercapacitors have been developed rapidly as a rechargeable energy storage device. And the performance of supercapacitors is depending on electrode materials, the preparation method and performance of electrode materials have become the primary goal of scientific development. This study synthesizes Co3O4@MnO2@PPy cathode material with porous pattern core-shell structure by hydrothermal method and electrodeposition. The result samples are characterized by X-ray diffraction transmission/scanning electron microscope, and X-ray photoelectron spectroscopy. Electrochemical evaluation reveals that electrochemical performance is significantly enhanced by PPy depositing. The specific capacitance of Co3O4@MnO2@PPy is 977 F g−1 at 1 A g−1, the capacitance retention rate of 105%. Furthermore, the electrochemical performance of Co3O4@MnO2@PPy//AC asymmetric supercapacitor assembles with AC as the negative electrode material is significantly better than that of MnO2//AC and Co3O4@MnO2//AC. The capacity of Co3O4@MnO2@PPy//AC is 102.78 F g−1. The capacity retention rate is still 120% for 5000 charge-discharge cycles.