LAUSR

A LiFePO4/C material with different amounts of iron phosphides was synthesized by a sol–gel method with different calcination temperatures. XRD, HRTEM, SEM, FTIR, BET, Raman, and magnetic measurements were carried out to characterize the physical properties of the LiFePO4/C, while EIS, CV, and charge–discharge tests were carried out to characterize the electrochemical performance. It is obtained that the crystallinity, the particle size of the LiFePO4, and the amount of iron phosphides in the sample are the factors that affect the electrochemical performance of the material, where the key factor determining the electrochemical performance varies in different situations. The samples possessing well-crystallized LiFePO4 particles and similar particle size demonstrated improved rate performance with the increasing amount of iron phosphides when the calcination temperature increased from 650 to 750 °C. The results showed that the rate performance could be improved by harmonious improvement of the ionic conductivity of Li+ and the electronic conductivity.