Advances in new cathode material LiFePO4 for lithium-ion batteries

The cathode materials of lithium-ion batteries are developing towards the direction of high energy density, long cycle life, low cost and environment friendly. As a potential ‘green’ cathode material for lithium-ion power batteries in the 21st century, olivine-type lithium iron phosphate (LiFePO4) become more attractive recently for its high theoretical capacity (170 mAh g−1), stable voltage plateau of 3.5 V vs. Li/Li+, good stability both at room temperature and high temperature, excellent cycling performance, high safety, low raw material cost, no pollution, and rich source of raw materials, etc. This paper introduces the research progress in recent years on the structure and performance, synthesizing methods, carbon-coating, ion-doping and particle size control. Furthermore, the prospect of LiFePO4 cathode material for the lithium-ion batteries is reviewed. (i) Preparation process of LiFePO4 (including high temperature solid-phase method, sol–gel method, microwave method, hydrothermal method, carbothermal reduction method, spray pyrolysis method and other synthesis routes). (ii) Progress on modification of LiFePO4 (three modification strategies including carbon coating, metal particle or ion doping and the optimization of the particle size and morphology). (iii) Finally, the trend of research and development of LiFePO4 is also pointed out (the follow-up studies should be directed at the theoretical study and process improvement).

► We highlight current knowledge on the lithium iron phosphate (LiFePO4).
► We analyze the methods used, and situations in which LiFePO4 have been investigated.
► Approaches to improve the performance of LiFePO4 is discussed.
► Future research on LiFePO4 cathode material is pointed out.