Investigation on the temperature tolerance of LiMn2O4 in lithium-ion batteries

Abstract

LiMn₂O₄ is one of the most popular cathode materials for lithium-ion batteries. However, temperature is one of the important factors that affects the electrochemical performance of materials. In this study, the electrochemical performance and capacity fade mechanism of LiMn₂O₄ at different temperatures (25 °C, 40 °C, 50 °C and 55 °C) have been investigated. The results show that the capacity degradation is not significant and the capacity retention rate is relatively high when the temperature is lower than 40 °C. Moreover, the EIS results show that the impedance of the battery is the smallest at 40 °C. This means that 40 °C is an appropriate temperature for the battery with aging cycles. With the increase in the temperature, the thickness of the SEI films also increases, which will severely hinder the transport of lithium-ions, and eventually lead to the serious degradation of the battery capacity and an increase in polarization. Therefore, the capacity losses of the batteries at different temperatures are analyzed, which provide a theoretical basis for the future development of LiMn₂O₄ and have important reference significance.