h-BN doped beta-MnO2 nanobelts composite as superior electrode materials for supercapacitors

摘要

The electrochemical performance of MnO2 electrode material is limited by its poor electrical conductivity and cationic-protonic diffusion. In this work, we introduce the preparation of a novel h-BN/beta-MnO2 nanocomposite as superior electrode materials for extremely promising supercapacitors. The phase, surface morphologies and the internal atomic structures of the nanocomposite were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscope (TEM). The electrochemical performance including cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS) was conducted under three-electrode system. The h-BN doped beta-MnO2 nanobelts composite electrode displayed a specific capacitance of 578.4F g(-1) at a current density of 0.5 mA cm(-2) (similar to 0.36 A g(-1)) and retained nearly 97.1 % capacitance even after 5000 cycles.