摘要
磷酸锰铁锂(LiMn_(x)Fe_(1-x)PO_(4),0<x<1,LMFP)凭借其显著的高能量密度、优异的热稳定性与固有的环境友好特性,已成为极具发展前景的锂离子电池正极材料,备受学术界与产业界关注。然而,其固有的低电子电导率和缓慢的离子扩散速率,严重制约了其在高性能电池中的广泛应用。本文聚焦解决LMFP电导率瓶颈这一核心挑战,重点探讨了提升其电子/离子电导率的多种策略。通过对不同改性方法的原理、优势、局限性以及实际应用效果的深入分析,为LMFP的应用提供理论依据和实践指导。
Lithium manganese iron phosphate(LiMnxFe1−xPO4,0<x<1,LMFP)has emerged as a highly promising cathode material for next-generation lithium-ion batteries.It inherits the exceptional safety profile,low cost,and structural stability of LiFePO4(LFP)with a higher operational voltage(~4.1 V vs.Li+/Li)and increased theoretical energy density due to the Mn2+/Mn3+redox couple.These attributes make LMFP a compelling candidate for applications demanding high energy density,such as electric vehicles and grid storage,particularly within the context of global decarbonization efforts.However,the widespread commercialization of LMFP faces significant hurdles.First,Its intrinsically low electronic and ionic conductivity severely restrict the improvement of rate capability and power density of LMFP,rendering it difficult to meet the demands of high-power applications.Sencond,LMFP also suffers from challenges associated with the Jahn-Teller distortion of Mn3+ions during cycling.This distortion induces severe lattice strain,promotes Mn2+dissolution into the electrolyte,and accelerates side reactions(e.g.,the formation of Li4P2O7).The dissolved Mn2+can migrate to the anode,damaging the solid electrolyte interphase(SEI)film on the anode surface.Meanwhile,this process consumes active lithium in the battery,increases polarization,and ultimately leads to rapid capacity fading and a significant decline in cycling stability.To overcome these limitations,extensive research focuses on enhancing LMFP’s conductivity and mitigating the Jahn-Teller effects.Key modification strategies include:1)Particle size optimization and morphology control:Reducing particle size and engineering crystal morphology(e.g.,maximizing the electrochemically active(010)facet)to shorten lithium-ion diffusion pathways.2)Surface coating:Conductive coatings(especially carbon-based materials)improve surface electronic conductivity and protect against electrolyte decomposition.3)Ion doping:Substituting cations(e.g.,Mg2+,Zn2+,Al3+,Nb5+)at Li,Fe,or Mn sites enhances bulk electronic/ionic conductivity and stabilizes the crystal structure.4)Composite electrodes:Combining LMFP with highly conductive materials improves overall electrode kinetics.Consequently,the implementation of these strategies leads to a significant enhancement in the electrochemical performance of LMFP.Summary and prospects Enhancing conductivity is pivotal for optimizing LMFP electrochemical performance.Current strategies effectively improve electronic conductivity via carbon coating,doping,conductive additives,and nanostructuring,while ionic conductivity benefits from morphology design,ion doping,and ionically conductive surface coatings.However,single modification approaches remain insufficient to fundamentally resolve LMFP’s low conductivity.Future research must focus on synergistic modification strategies,constructing integrated 3D electron/ion conduction networks within particles and electrodes.Additionally,deeper investigation into microstructure-property relationships is essential to guide material optimization.This will enable cost-effective ultra-fast charging solutions for new energy vehicles and grid storage,advancing high-safety,long-lifetime,high-rate lithium batteries for energy transition.
作者
刘洋汐
伍业华
梁正
周嘉俊
张锐斌
郑枫浩
赵伟彬
仲皓想
LIU Yangxi;WU Yehua;LIANG Zheng;ZHOU Jiajun;ZHANG Ruibin;ZHENG Fenghao;ZHAO Weibin;ZHONG Haoxiang(School of Marine Equipment Engineering,Guangzhou Maritime University,Guangzhou 510725,China;Guangzhou Institute of Energy Research,Chinese Academy of Sciences,Guangzhou 510640,China)
出处
《硅酸盐学报》
2026年第1期286-296,共11页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金面上项目(22075288)
中国科学院河南产业技术创新与育成中心开放性课题项目(2024123)
广东省普通高校重点领域项目(2024ZDZX3036)
广州市教育局高校科研项目(2024312482)
广州交通大学(筹)引进人才科研启动(K42024045)。
关键词
磷酸锰铁锂
电子电导率
离子电导率
改性研究
lithium manganese iron phosphate
electronic conductivity
ionic conductivity
modification methods
