Review on Defects and Modification Methods of LiFePO₄ Cathode Material for Lithium-Ion Batteries

In recent years, domestic and international researchers have been committed to the research of lithium-ion batteries. As the key to further improving the performance of the battery, the quality of the cathode material directly affects the performance indicators of the lithium battery; thus, the cathode material occupies the core position in the lithium-ion battery. LiFePO4 is a relatively excellent material for lithium-ion batteries, which has many advantages of low cost, high capacity, and environmental friendliness. However, as a result of the low conductivity of lithium iron phosphate and the slow diffusion rate of lithium ion, the development of lithium iron phosphate in the power battery industry is restricted. As a power battery applied in real life, there is still a lot of research space in energy density, consistency, and low-temperature performance. After years of efforts, researchers continue to explore the charging and discharging principle of lithium iron phosphate, to optimize the synthesis route, and to try coating, doping modification, and other methods to improve the performance of the material. This paper analyzes and summarizes the defects of lithium iron phosphate cathode materials and modification methods and provides an outlook on the future research direction of lithium iron phosphate.