Effects of operating temperature on the electrochemical performance of a LiMn0.5Fe0.5PO4 cathode material for lithium ion batteries

Abstract

Electrochemical performance of cathode materials for Li-ion batteries depends on their operating conditions, especially temperature. Currently, LiMn0.5Fe0.5PO4 (LMFP) cathode materials have attracted worldwide attention because of their low cost, low environmental impact, good electrochemical performance and high operating voltage, between 3.5 and 4.1 Volts. We investigated the effects of temperature on the electrochemical properties of LMFP. In this work, LMFP was prepared via a solvothermal method. We evaluated their electrochemical reactions using galvanostatic charge-discharge (GCD) cycling and electrochemical impedance spectroscopy (EIS) at temperatures of 15, 30, and 45 °C. The crystalline structure and morphology of LMFP were characterized using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM). The results showed that the discharge capacities of LMFP increased with temperature, which corresponded to lower charge transfer resistance within the cell and higher lithium-ion diffusion at elevated temperatures.