An efficient supercapacitor of three-dimensional MnO2 film prepared by chemical bath method

MnO2 film is directly grown on Ni foam substrate by a facile chemical bath deposition method. The microstructure characterization of as-prepared MnO2 film is conducted by SEM, XRD and nitrogen adsorption and desorption measurements. The beta-MnO2 film consists of a large number of round nanoplatelets cross-linked with each other and forms 3D porous microstructure with a BET area of 80.6 m(2) g(-1) and an average pore diameter of 3.8 nm. The electrochemical performance of MnO2 film electrode is investigated by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge measurements. The obtained MnO2 film electrode without binder additive shows excellent pseudocapacitance behavior, delivering the maximum capacitance of 1517 F g(-1) in KOH and 546 F g(-1) in KNO3 at a current density of 1 A g(-1). This study provides a facile method for preparation of three-dimensional MnO2 film with efficient supercapacitive properties. (C) 2016 Elsevier B.V. All rights reserved.