MnO2 depositing on the surface of hollow porous carbon microspheres for supercapacitor application

Abstract

A supercapacitor electrode material was synthesized by using hollow carbon spheres prepared via high temperature sintering of dopamine hydrochloride and subsequent coating with MnO2. SEM, TEM and analysis of energy pattern were used to characterize the structure, morphology and elemental composition of the material, which proved that the material had a good hollow structure and uniform surface morphology, and that MnO2 was successfully coated on the surface of the carbon material. Electrochemical characterization using charge-discharge cycles at constant current and other methods show that the prepared materials have good specific capacitance and cycle stability, and have a specific capacitance of 198 F.g−1 at a current of 1 A·g−1. When the charge and discharge cycle is carried out at 10 A·g−1 for 5000 cycles, the capacitance remains stable at more than 180 F·g−1.