Effects of current density on preparation of grainy electrolytic manganese dioxide

Abstract

Grainy electrolytic manganese dioxide was prepared by electrodeposition in a 0.9 mol/L MnSO₄ and 2.5 mol/L H₂SO₄ solution. The structure, particle size and appearance of the grainy electrolytic manganese dioxide were determined by powder X-ray diffraction, laser particle size analysis and scanning electron micrographs measurements. Current density has important effects on cell voltage, anodic current efficiency and particle size of the grainy electrolytic manganese dioxide, and the optimum current density is 30 A/dm². The grainy electrolytic manganese dioxide electrodeposited under the optimum conditions consists of γ-MnO₂ with an orthorhombic lattice structure; the grainy electrolytic manganese dioxide has a spherical or sphere-like appearance and a narrow particle size distribution with an average particle diameter of 7.237 µm.

Keywords

alkaline batteries / electrolytic manganese dioxide / current density / electrodeposition