锂离子电池正极材料LiFePO_4/C的研究进展

Research progress of LiFePO_4/C cathode material for Li-ion batteries

橄榄石型LiFePO4正极材料具有原料来源丰富、无毒、环境友好、理论容量较高、热稳定性和循环性能好等特点,是近年来迅速发展起来的一种锂离子电池的正极材料。但是由于纯LiFePO4的电子导电率低及锂离子扩散速度慢等缺点,限制了其工业化。针对这种情况,近些年来研究人员从合成方法,表面改性,金属掺杂等方面对磷酸铁锂做了许多的研究工作,其中一种有效的方法就是在LiFe-PO4的表面包覆碳,增加导电率,减小材料颗粒尺寸,提高电化学性能。对近年来的LiFePO4的合成方法及碳包覆原理进行了综述。

Olivine LiFePO4 has the potential to be a new kind of cathode material for lithium ion battery due to its abundant resources, non-toxicity, environmental benign, high theoretical capacity,good thermal stability and excellent cycling performance. But the intrinsic defects of poor electronic and ionic conductivity have limited its application in industry. Some researchers had done lots of work from synthesis method,surface modification and modification by metal doping. It was found that some carbon-coating on LiFePO4 could improve its property, this is the way to enhance ionic conductivity, reduce particle size and improve its electrochemistry performance. The paper summarizes synthesizing methods of LiFePO4 and theory of carbon-coating.