Effect of High-Energy Ball Milling Mixing Process on Electrical Performance and Synthesis Temperature of LiFePO4/C Cathode Material

Abstract

In this paper, high-energy ball milling method was used to prepare LiFePO4/C precursor and high temperature solid phase method to prepare LiFePO4/C cathode material. The influence of mixing process on the electrical performance and synthesis temperature of LiFePO4/C cathode material was studied by changing the ball milling time.The ball milling time selected in this paper is 0, 0.5, 1, 1.5, 2 h, and XRD, SEM and particle size analysis are used to characterize the properties of LiFePO4/C powder. The research results show that the LiFePO4/C powder obtained under the ball milling time of 1 h has the smallest particle size and uniform distribution. The XRD results also show that the LiFePO4/C phase obtained under this condition has good purity and crystallinity.The electrical performance of the LiFePO4/C material prepared after high-energy ball milling are tested. The results show that the first discharge specific capacity at 0.2 C rate is 163.3 m·Ah/g, which is 19.7% higher than that of the non-ball milled sample.The TG-DTA curve results show that the reaction temperature of the sample after high-energy ball milling is 454 °C, and the mass loss ends at about 570 °C. Compared with the sample without ball milling, the reaction temperature is reduced by 60 °C.The results of this study show that the preparation of precursor by high-energy ball milling can effectively improve the electrical performance of LiFePO4/C materials and reduce the material synthesis temperature.