钛酸锂作为锂离子电池负极材料的改性进展

Progress of modification of lithium titanate as anode material for lithium-ion battery

钛酸锂因零应变特性已成为性能优异的锂离子电池负极材料,但导电性差和锂离子扩散率低等问题限制了其广泛应用.在介绍钛酸锂主要制备方法的基础上综述了国内外对于该材料作为锂离子电池负极材料的改性方法,包括体相内的金属离子掺杂、碳包覆和氮化处理等表面改性手段以及材料粒子的大小和形貌控制等.除了体相内锂位的掺杂对材料性能提升不明显外,导电层包覆和颗粒纳米化对材料性能都有较大的提高,因此对于钛酸锂体相内氧位或锂位的掺杂是比较有价值的研究方向.要同时提高材料的离子导电率和电子导电率必须从多个方面综合考虑和设计.

Lithium titanate has become the lithium-ion battery anode material for its little volume effect and excellent electrical properties,but the poor electron conductivity and lithium-ion diffusion rate still limit its further application.Based on the introduction of the main preparation methods of lithium titanate,the modification for lithium titanate as anode materials for lithium-ion batteries at home and abroad are reviewed,including doping certain metal ion inside the bulk phase,surface coating by carbon and nitriding treatment,and the control of particle size and morphology etc..In addition to doping at titanium site lithium titanate,coating by conductive materials and decreasing the particle size both are proved to give a positive boost in the material performance,so the doping at oxygen or lithium site in lithium titanate bulk phase is probably of more research value.It must be considered and designed from comprehensive aspects to improve the ionic conductivity and the electronic conductivity at the same time.