磷酸铁锂正极材料掺杂改性的研究进展

Research Process on Rate Performance of Ion Doped LiFePO_(4) Cathodes

磷酸铁锂正极材料自身的电子电导率低、锂离子扩散系数小等缺点,制约了其在高倍率电池领域的发展。本文综述了离子掺杂改善磷酸铁锂电极材料倍率性能的研究现状,并提出掺杂改性的发展趋势。Li位掺杂、Fe位掺杂和O位掺杂,均可使材料的晶格产生缺陷及晶格畸变,提高材料的电子电导率和离子电导率。Li位掺杂和O位掺杂的离子种类少,倍率性能和循环性能改善不明显;Fe位掺杂因金属离子的种类多,改性效果显著,成为最具发展前景的技术方法。继续进行深入的理论研究和工艺改进,是今后磷酸铁锂正极材料掺杂改性的重点研究方向。

The extensive application of lithium iron phosphate cathode material on high rate power battery field was constrained by the instinct disadvantage such as poor conductivity,slow lithium ion diffusion rate and so on.The ion doping methods for improvement of rate capacity of lithium iron phosphate cathode material,and the development trend were introduced in this paper.The Li,Fe and O-site substitution could result in lattice distortion and crystal lattice distortions,promising enhanced electron and ionic conductivity.Li and O-site substitution had no significant effect on improvement of rate capability and cycling properties for little species,while Fe-site doping had most promising method due to the various metal ions and the remarkable impact on the electrochemical performance.Besides,theoretical study and technology improvement would become a major focus of research on modification of lithium iron phosphate cathode material.