富锂锰基正极材料研究进展

随着社会发展,电动汽车、消费类(3C)电子产品、储能装置等对锂离子电池的能量密度提出了更高要求。富锂锰基正极材料具有高比容量(≈250 mAh/g)、高工作电压(≈3.6 V)及低成本等优势,有望成为下一代商用高比能电池正极材料。首次库仑效率低、倍率性能差、电压/容量衰减快等问题限制了富锂锰基正极材料的工程化应用。本文综述了富锂锰基正极材料的最新研究进展,重点从材料结构、电化学反应机理、失效机制和改性方法等几方面进行了阐述。研究表明,采用离子掺杂、表面包覆、晶体结构调控等技术,可显著改善富锂锰基正极材料的电化学性能。最后,对富锂锰基正极材料的发展方向进行了展望。

Research progress on Li-and Mn-rich cathode materials for lithium-ion batteries

As the development of society,the specific energy density of the commercial lithium-ion battery still cannot meet the requirements for practical applications,such as electric vehicles,3C(computer,communication and consumer electronics)products and energy storage devices.The Li-and Mn-rich cathode materials are expected to be the key electrode materials for high energy density lithium-ion battery due to their high electrochemical capacity(≈250 mAh/g),high operating voltage(≈3.6 V)and low cost.However,several issues and challenges limit their widespread applications for commercial lithium-ion battery,including high irreversible capacity,poor cycle life and fast voltage/capacity fading.In this paper,the latest research progress of Li-and Mn-rich cathode materials is reviewed,with emphasis on material structure,electrochemical reaction mechanism,failure mechanism and modification technology.The results show that ion doping,surface coating,crystal structure regulation and other techniques can significantly improve the electrochemical performance of Li and Mn-rich cathode materials.Finally,the development direction of Liand Mn-rich cathode materials is prospected.