Charge storage behavior of sugar derived carbon/MnO2 composite electrode material for high-performance supercapacitors

Abstract

Herein, we present an efficient and simple method to develop a 3D-Carbon /MnO2 (C/MnO2) composite active material for high-performance supercapacitors. MnO2 nanorods are synthesized by the hydrothermal process, and corresponding carbon composite is synthesized from table sugar precursors using the combustion process. MnO2 has rod-like morphologies and forms 3D electrode architectures with carbon, and contains about 5–10 nm of carbon coating. The charge storage behavior studied by galvanostatic charge-discharge cycling shows capacitance of 416 F g−1 at 1 A g−1 with capacitance retention of 90% after 5000 cycles. The superior electrochemical performance is attributed to the one–dimensional ion transport of Mn ion, the in-situ 3D electrode architecture, and carbon coating that enhances the conductivity and the surface area of MnO2. C/MnO2 composite exhibits an energy density of 60 Wh kg−1 with a power density of 201 W kg−1. The combined pseudocapacitive behavior of MnO2 and electric double-layer capacitors property of carbon exhibits significant electrochemical performance in the aqueous electrolyte. The synthesis approach uses environment benign active materials with the low cost of electrode fabrication provides an alternative route for the development of high-performance supercapacitors.