A new binary composite of MnO2/PANI has been synthesized as electrode material for energy storage. In the composite, the MnO2 nanospheres with a honeycomb-like structure are coated with PANI layers, in which MnO2 serve as a scaffold for PANI layer and PANI act as a protective coating layer to restrain MnO2 nanospheres from dissolution in acidic electrolyte, and causing a synergic effect. The composite, when the mass ratio of MnO2 and aniline is 1:1, exhibits a high specific capacitance of 565Fg−1 (specific capacity of 126mAhg−1) at a discharge current density of 0.8Ag−1 and a high specific capacity of 143mAhg−1 at the scan rate of 20mVs−1 in 0.5M Na2SO4-0.5M H2SO4 solution. In addition, the electrode material retains about 77% of the initial capacitance after 1000 cycles of charge-discharge at 8Ag−1. These results demonstrate that the special morphology and shorter diffusion pathways (SEM and EIS) make the binary composite a promising candidate for future energy storage applications.