Synthesis and electrochemical performance of MnO2/BC composite as active materials for supercapacitors

Abstract

A series of bamboo charcoal (BC)-doped MnO2 particles were synthesized via a simple and rapid hydrothermal method and the subsequent milling process. The effects of BC doping on the structure and morphology of the products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and nitrogen adsorption/desorption measurements. The results indicate that the as-prepared MnO2 is α-MnO2 microspheres, and FESEM images show that the BC particles are homogeneously distributed and embedded in the MnO2 matrix. The 3wt.% BC-doped MnO2 particles show BET surface area of 180 m2g−1. Electrochemical test results indicatethat the MnO2-3wt.% BC composite exhibits the best electrochemical performance with initial specific capacitance of 306.9, 304.9, 300.9, 299.4 and 297.4 F g−1 at 100, 150, 200, 250 and 300mAg−1, respectively. After 500 cycles, the capacitance of the capacitor is still kept about 100% at 300mAg−1, suggesting that the MnO2-3wt.% BC composite materials can be used as ideal electrode materials in supercapacitors.