基于锂离子电池正极材料的一元/二元复合正极材料研究进展

Research progress of mono/binary composite cathode materials based on lithium-ion battery cathode materials

以单一正极材料LiCoO2、LiFePO4和LiMO2(M=NixCoyMnz/Alz,x+y+z=1)等为代表的锂离子电池,因其比容量高、能量密度大和循环寿命长等优点被广泛应用于航天航空、电动汽车以及电子设备等领域中。然而,这些单一正极材料因结构极其不稳定、不可逆容量损失高、循环稳定性差、安全性低和导电性低等问题阻碍了在大型动力能源设备上的应用。对此,回顾了单一正极材料在不同领域中的应用情况并描述了其主要缺陷及诱发原因。结果发现,将单一正极材料与其他非正极材料或正极材料复合制备得到的一元/二元复合正极材料能有效解决以上问题,从而从根本上提高电化学性能及循环稳定性。据此,综述了基于锂离子电池正极材料的1+0型和1+0+0型一元复合正极材料以及1+1型和1+1+0型二元复合正极材料(其中1表示锂离子正极材料,0表示非锂离子正极材料)的研究进展,深入分析了上述两大类复合正极材料下4种类型的14种不同结构组合的复合正极材料的电化学性能。最后,阐述了其存在的主要问题,并对今后的发展方向和值得研究的应用价值进行了展望。

Lithium-ion batteries composed of single cathode materials,such as LiCoO2,LiFePO4,and LiMO2(M=NixCoyMnz/Alz,x+y+z=1),are widely used in aerospace aviation,electric vehicles,and electronic equipment due to their high specific capacity,large energy density,and long cycle life.However,these single cathode materials have an unstable structure,high irreversible capacity loss,poor cycle stability,low safety,and low conductivity,which restricts their application in large-scale power equipment.In this regard,we conducted a review of the literature on the application of single cathode materials in various fields and described their primary defects.It was found that a mono/binary composite cathode prepared by combining a single cathode material with other materials(cathode or non-cathode)can effectively solve the aforementioned problems,thereby improving the electrochemical performance and cycle stability of lithium-ion batteries.More specifically,this article presents a review on the research progress of 1+0 type and 1+0+0 type mono composite cathode materials,and 1+1 type and 1+1+0 type binary composite cathode materials based on lithium-ion battery cathode materials.In this series,1 represents a lithium-ion cathode material and 0 represents a non-lithium-ion cathode material.Moreover,we analyzed the electrochemical performance of the four types of composite cathode materials with 14 different structural combinations.Finally,the main problems of composite cathode materials are explained and suggested development directions are proposed.