Preparation of an electrochemically-formed spinel lithium manganese oxide and its charge-discharge behaviors

摘要

Manganese hydroxides were prepared by a cathodic electrochemical precipitation from a manganese nitrate solution. TV grass blade-like precipitate, which is ascribed to manganese hydroxide was 20-80 mu m long and 1-5 mu m wide and was spread, out on a Pt substrate after the electrochemical precipitation. When the electrochemically precipitated manganese hydroxides were kept in an alkali metal hydroxide aqueous solution, such as NaOH, KOH and LiOH, the respective alkali metal ion was incorporated into the precipitate. Filer-like nano-structured spinel-LiMn_2O_4 crystals 200nm in diameter were obtained on a substrate by the calcination of the Li incorporated precipiiatc al 750 deg C without any additives. The electrochemically-formed spinel-LiMn_2O_4 showed well-shaped CVs, even in higher scan rates. These behaviors are ascribed to the crystal size and shape of the processed spinel- LiMn_2O_4