锂离子电池正极材料LiMn2O4的研究进展

具有尖晶石相的LiMn₂O₄因价格低、无毒、无环境污染、制备简单、研究较成熟,因此有着很好的应用前景,被看作最有可能成为新一代商用锂离子二次电池正极材料.由于LiMn₂O₄电化学循环稳定性能不好,表现在可逆容量衰减较大,尤其在高温下(>55℃)使用衰减更严重,从而限制了它的商业化应用.经过近十几年的研究,人们对其衰减机理有了比较清晰的了解,提出了造成容量衰减的几种可能原因如Jahn-Teller畸变效应、Mn²⁺在电解质中的溶解、出现稳定性较差的四方相以及电解质的分解等.通过掺杂、表面包覆、制备工艺的改进,人们已能制得循环稳定性能较好的尖晶相材料.本文结合我们研究小组的最新研究成果对锂离子二次电池正极材料LiMn₂O₄的最新研究进展进行综述和评论.

Review of Cathode Material LiMn2O4 for Lithium Ion Batteries

Spinel LiMn₂O₄ has been considered to be the most promising alternative cathode material for the new generation of lithium ion batteries in terms of its low cost, non-toxicity and easy manufacture. However, the capacity fading rapidly upon charge/ discharge cycling, especially at the high working temperature (>55℃), hinders its commercial application. Over the past decade much work has been devoted to the spinel LiMn₂O₄ and its several fading mechanisms have been proposed such as Jahn-Teller distortion, dissolution of Mn²⁺ into electrolyte, electrolyte decomposition and transformation of cubic to unstable tetragonal phase, etc. Its capacity retention could be improved much by doping, surface coating and improving preparation technique. The recent developments in cathode material LiMn₂O₄ have been reviewed in this paper based on the recent results in our research group.