磷酸锰铁锂正极材料改性研究进展  

Research progress in lithium manganese iron phosphate cathode material modification

作　　者：文志朋 潘凯 韦毅 郭佳文 覃善丽 蒋雯 吴炼[2,3] 廖欢 WEN Zhipeng;PAN Kai;WEI Yi;GUO Jiawen;QIN Shanli;JIANG Wen;WU Lian;LIAO Huan(Institute of New Functional Materials of GIIT Co.LTD.,Nanning 530200,Guangxi,China;Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology,Guangxi University,Nanning 530004,Guangxi,China;Institute of Chemical Engineering,Guangdong Academy of Sciences,Guangzhou 510665,Guangdong,China)

机构地区：[1]广西产研院新型功能材料研究所有限公司,广西南宁530200 [2]广西大学,广西石化资源加工及过程强化技术重点实验室,广西南宁530004 [3]广东省科学院化工研究所,广东广州510665

出　　处：《储能科学与技术》2024年第3期770-787,共18页Energy Storage Science and Technology

基　　金：广西科技基地与人才专项(桂科AD23026031);广西科技基地与人才专项(桂科AD23023009);广西石化资源加工及过程强化技术重点实验室开放课题(2022K013);南宁市重大科技专项(20221021);南宁市重大科技专项(20231036)。

摘　　要：正极材料是决定锂离子电池性能的关键材料之一,直接影响电池的能量密度、循环寿命、倍率性能及安全性能。橄榄石型LiMnFePO4具有能量密度高、成本低、环境友好、安全稳定等优点,被认为是一种很有前途的锂离子电池正极材料。然而,LiMnFePO4具有橄榄石结构磷酸盐基化合物电子电导率低、Li+一维扩散速率慢等固有缺陷,严重阻碍了其在高性能锂离子电池中的大规模应用。如何提升LiMnFePO4的导电子/离子性能,是当前需要解决的关键问题。本文全面综述了LiMnFePO4正极材料的结构特征、合成方法及其导电性能提升的研究进展,着重介绍了表面包覆、形貌控制和离子掺杂等方法对提升LiMnFePO4正极材料导电性能的效果及其作用机理,虽然上述三类改性方法均可一定程度地优化材料颗粒间电子/离子传输路径,实现LiMnFePO4正极材料导电性能的提升。但是单独采用这些方法依然难以从根本上解决LiMnFePO4导电性差的问题。为进一步提升LiMnFePO4正极材料的综合性能,本文在总结当前研究进展的基础上,对LiMnFePO4未来的研究思路和发展方向进行了展望。提出了通过杂原子掺杂优质碳材料包覆、短b轴形貌控制以及离子掺杂等方法联合改性的策略。该策略有望进一步提升LiMnFePO4正极材料的导电性能,获得高容量、高倍率、高稳定性的LiMnFePO4正极材料。Cathode materials are vital for lithium-ion batteries(LIBs)because they determine their performance by directly affecting the energy density,cycle life,rate,and safety of these batteries.Olivine-type LiMnFePO4 is a commercial LIB cathode material with good market prospects due to its high energy density,low cost,environmental compatibility,stability,and safety.However,the inherent shortcomings of LiMnFePO4,such as low electronic and ionic conductivity,seriously hinder its large-scale commercial application in high-performance LIBs.Thus,improving the electron and ion conductivity of LiMnFePO4 is an urgent problem to solve.This review comprehensively discusses the structural characteristics,synthesis methods,and the recent research progress in LiMnFePO4 cathode materials.Improving the conductivity of LiMnFePO4 cathode materials by surface coating,morphology control,and ion doping is discussed.Although these three modification methods can optimize the electron and ion transport path in the LiMnFePO4 matrix,the problem of poor electronic and ionic conductivity is difficult to solve via a single method.To improve the comprehensive performance of LiMnFePO4 cathode materials,this paper summarizes the current research progress and proposes future research directions for LiMnFePO4.The modification strategy of combining carbon-doped heteroatom coating,control of the short b-axis morphology,and ion doping is considered an effective remedy for the poor electronic and ionic conductivity and can endow LiMnFePO4 cathode materials with high capacity and high stability.

关 键 词：磷酸锰铁锂 导电性能 表面包覆 形貌控制 离子掺杂 

分 类 号：O646.54[理学—物理化学]