关键词: LiMn_2O_4, 高温行为, 容量衰减

Abstract: The capacity loss of spinel LiMn2O4 cathode at elevated temperatures was evaluated by constant current charge_discharge methods and it was found that serious capacity loss and cycleability decrease occured at above 50 , especially for the charged cells. The mechanisms for this phenomena were examined by atomic emission and infrared spectrometry of the electrolyte, XRD measurment of the cycled elecrode and microelectrode voltammetry of LiMn2O4 at room and elevated temperatures. The results showed that with increasing temperature, Mn and Li ions tended to redistribute partly in the spinel framework due to the disproportion of Mn3+ ions and this results in a rapid increase in Mn dissolution and a catalytic decomposition of the electrolyte. All these factors combiningly play a dominated action for the observed capacity fading of LiMn2O4 electrode.

Key words: LiMn2O4, Capacity loss, Higher temperature