Research Progress on the Surface Carbon Coating Modification of LiFePO4 Cathode Material for Lithium Ion Batteries

New energy materials play an important role for the sustainable development of the human society. Ferrous lithium phosphate(LiFePO4) as one of the cathode materials of lithium-ion battery, with low-pollution, high safety, low-cost and other some merits can conduct the lithium reversible intercalation and deintercalation and complete the charge and discharge orderly at certain current density, so, it is a promising battery cathode material and has made remarkable development and progress. Its crystal structure is olive type and the change of volume structure is a little and maintains relatively stable, all of which guarantee the collapse and deformation of the structure under the condition of charge and discharge. However, the two deadly drawbacks that hinder the development of LiFePO4 material are the low electronic and ionic conductivity, which lead to the poor cycling and rate performance of LiFePO4. Therefore, in response to those questions, many improving methods are given by people, such as dropping other elements on Li and Fe site, nanoparticles and surface coating of conductive materials. Yet, coating modification on the surface of LiFePO4 cathode material to improve its rate performance and cycle life is the most widely used and economically feasible method. Carbon material is widely used in the coating of lithium iron phosphate because of its low-cost, non-toxic, environment-friendly, rich raw material and high conductivity. This paper mainly introduces the research progress of modified LiFePO4 cathode materials with surface carbon coating, and the selection of carbon sources, carbonization mechanism and surface chemical reaction are summarized. © 2020, Materials Review Magazine. All right reserved.