The materials, cell design, manufacturing and BMS technologies of Li-ion batteries are summarized. LiMn₂O₄ is widely used for light EVs and HEVs. It is also commonly used to mix with NCM for improving cell's safety and rate performance. LiFePO₄ shows very high stability and it is suitable for long life and safety batteries for PHEVs and other EVs which need batteries with medium energy density and long cycling life. NCM and NCA have higher specific capacity and they are used for high energy type cells with ceramic coating layers on separator and/or electrodes for improving safety. Graphite is almost the only anode for EV cells and the effort to add Si to carbonaceous anode material is continuing. Liquid electrolyte with higher charge cutting voltage and wide working temperature range is being developed. Small cylinder cells, large size prismatic metal can cells and soft pack cells co-exist for different designs of xEVs. Machines made in China for cell manufacturing grow quickly with improved technologies. Large efforts are still to be made from xEV side and cell side to improve safety and reliability of battery packs. Li-ion battery is the best candidate of electricity storage unit for xEVs at present and in the near future. Its energy density will reach 300 (W·h)/kg at cell level in the near future and will serve the new energy vehicles in the next decade.

electric vehicle  /  Li-ion battery  /  materials  /  battery system