Hydrothermal regulation of MnO2 on a wood-based RGO composite for achieving wide voltage windows and high energy density supercapacitors

Abstract

Summary: The increasing need for improved energy storage devices renders it particularly important that inexpensive electrodes with high capacitance, excellent cycling stability, and environment-friendly characteristics are developed. In this study, a wood-derived carbon@reduced graphene (WRG) conductive precursor with an average conductivity of 15.38 S/m was firstly synthesized. The binder-free WRG-MnO2 electrode was successfully constructed by growing MnO2 onto a WRG under hydrothermal conditions. The asymmetric supercapacitor assembled with the WRG-20MnO2 cathode exhibited excellent electrochemical capacitive behavior with a voltage window of 0–2 V, maximum energy density of 52.3 Wh kg−1, and maximum power density of 1642.7 W kg−1, which is mainly due to the distinctive icicle-shaped structure of the MnO2. Thus, a facile strategy for developing high-performance hierarchical porous carbon electrodes that can be used in supercapacitors was developed herein, which may provide new opportunities to improve the high added value of poplar wood.

Keywords

• Natural sciences
• Applied sciences
• Materials science