锂电池正极材料LiFePO4性能研究进展

LiFePO4是最有发展前景的锂离子电池正极材料之一,它具有结构稳定,循环可逆性好,安全无毒等优点。但由于其电导率低和Li+扩散系数小,导致在大倍率充放电时性能较差,阻碍了在大功率电池领域的应用。本文结合LiFePO4的结构和充放电原理,阐述了表面包覆、掺杂、粒度控制等改性手段,以及添加导电剂等对LiFePO4性能的影响。改性是提高其倍率性能的有效手段,提高了LiFePO4颗粒表面和内部的导电性;添加导电剂,可以形成导电网络,进一步提高了LiFePO4作为锂电池正极材料的电化学性能。

Review on Performance of LiFePO4 Cathode Material

LiFePO4 is one of the most promising lithium ion batteries cathode materials with advantages of stable structure, good cycle reversibility, safety and non-toxic, but its poor electrochemical performances with low electronic conductivity and small Li＋ diffusion coefficient confine the applications to the field of high-power batteries. Combining with the structure of LiFePO4 and chargingdischarging principle, several measures, which affect the performance of LiFePO4, such as modifications, e.g. surface coating, ion doping, compound particle size controlling, and conductive additives are reviewed. Modifications improve surface and internal electrical conductivity of the LiFePO4 particles, increasing the rate performance; conductive additives form conductive network, and further improve the electrochemical performance of LiFePO4 as lithium battery cathode material.