MoO3 nanobelts integrated with partially-exfoliated graphite paper for high-performance supercapacitors

Abstract

Due to its excellent electrochemical properties, MoO3 is considered to be a promising electrode material in the field of energy storage, but it still suffers low electronic conductivity and serious aggregation. Herein, the partially expanded graphite paper (EGP) with a three-dimensional porous structure is synthesized by a cathodic electrochemical exfoliation, serving as a conductive substrate for the in-situ growth of MoO3 nanobelts via a simple hydrothermal method. The self-supporting MoO3/EGP composite material directly used as the electrode material of the supercapacitor, shows a high specific capacitance of 7.1 F cm−2 at 1 mA cm−2. In addition, the assembled symmetrical supercapacitor by using MoO3/EGP as electrodes offers an energy density of 0.77 mWh cm−2 at a power density of 2.41 mW cm−2 and the capacitance retention is 84.1% after 5000 cycles at 10 mA cm−2, indicating the excellent cyclic stability. The remarkable electrochemical performance of MoO3/EGP is attributed to the self-supporting porous structure of EGP with high electronic conductivity, which not only effectively prevents the aggregation of MoO3 nanobelts but also promotes the transfer kinetics of ion and electron.