Synthesis of electrode materials by reduction of KMnO4 with NiCl2·6H2O in aqueous solutions

The nickel–manganese compounds were synthesized by redox reactions in aqueous solutions using potassium permanganate as an oxidizing agent at ambient temperature. Also, a layered Li–Ni–Mn–O system was synthesized by using a nickel–manganese compound as precursor for electrode materials. X-ray diffraction patterns of the lithiated Li1.296Ni0.056Mn0.648O2 sample were indexed to a layered structure based on hexagonal α-NaFeO2 (space group: R-3m, 166) with signs of monoclinic-related peaks indicating the existence of monoclinic Li2MnO3 phase. The lithiated Li1.296Ni0.056Mn0.648O2 electrode provides the initial discharge capacity of 108 mAh g−1 and the maximum discharge capacity of 192 mAh g−1 between 2.0 and 4.8 V versus Li/Li+ at 0.2 mA cm−2.