电动汽车动力电池技术研究进展

 从锂离子电池材料技术、单体电池、电池系统等几个方面对锂离子动力电池的发展进行了评述。锰酸锂一般应用于轻型电动车辆,也可与三元材料混合提升新能源车辆用电池的安全性和倍率性能;磷酸铁锂适用于中等比能量要求的动力电池;三元材料通过材料、隔膜涂层和电池技术的改进提升安全性后适用于高比能量型电池;石墨负极目前仍然是广泛应用的负极材料,在碳负极材料中添加硅等高容量材料的努力仍在进行中,液体电解液在向高电压和宽工作温区方向发展;小圆柱电池、方形金属壳电池和软包电池各有特点,适应了多元化的电动汽车应用需求,国产制造设备技术水平持续提升,电池系统技术方面需要整车和电池方面合作努力以提升安全性和可靠性。锂离子动力电池是目前最具实用价值的动力电池,预期其比能量在不久的将来可提升至300 (W·h)/kg,满足新能源汽车产业未来10年的发展需求。

An overview of xEVs battery technologies

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.