Nano-Mn3O4 + PbO2 composite electrode materials with different compositions are prepared by anodic composite electrodeposition in Pb2+ plating solution containing suspended nano-Mn3O4 particles (40-60 nm). The particles are synthesized via one-step homogeneous precipitation at low temperature. The composite materials are characterized by X-ray diffraction (XRD). X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) analyses. The results indicate that the composite composed of gamma-Mn3O4 and beta-PbO2 is porous and quasi three-dimensional (3D), and its maximum electrochemically effective area ratio (R-F) is 72. The capacitance performance of the composite is determined by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and charge-discharge test. The composite shows a high specific capacitance up to 338 Fg(-1). (C) 2012 Elsevier Ltd. All rights reserved.