新一代动力锂离子电池磷酸锰锂正极材料的研究现状与展望

Research Status and Application Prospects of LiMnPO_4 as A New Generation Cathode Material for Lithium-Ion Batteries

磷酸锰锂正极材料具有能量密度高、成本低、安全性高和热稳定性好等优点,目前已成为锂电产业界研究的热点,有望成为继磷酸铁锂之后的新一代正极材料.然而,磷酸锰锂的电子电导率和锂离子扩散率均很低,其电化学性能提高较为困难,至今尚无法制备出满足实际应用的高性能磷酸锰锂正极材料,严重制约了磷酸锰锂材料及其电池的发展.本文从磷酸锰锂的结构特性出发,对近年来国内外在碳包覆、离子掺杂、纳米化和控制晶体形貌等改性研究、全电池研究、专利情况以及商业化尝试等多方面进行了综述,并对磷酸锰锂的发展进行了展望.

Olivine-structured lithium manganese phosphate(LiMnPO4) has the following advantages: excellent thermal stability, low cost, high safety and environmental benignity. Importantly, the theoretical energy density of LiMnPO4 is about 20% higher than that of commercialized LiFePO4 due to its higher Li+ intercalation potential of 4.1 V(vs. Li+/Li). Moreover, the high operating voltage of LiMnPO4 is compatible with present non-aqueous organic electrolytes of lithium-ion batteries. Therefore, LiMnPO4 is considered as a next generation cathode material for lithium-ion batteries. However, Li Mn PO4 suffers from poor electronic conductivity and low lithium diffusivity, resulting in its low discharge capacity and poor rate capability. And these intrinsic disadvantages hinder LiMnPO4 from its practical applications in lithium-ion batteries. In this paper, recent researches in the modifications includi ng carbon coating, ion doping, nanoization and cyrstalline morphological controlling, full cells, patent situation and commercial progress are reviewed. The prospects of its future development are also predicted. Particularly, the experimental data by Advanced Li-ion Battery Engineering Lab fully proves that LiMnPO4 has the feasibility of applying in lithium batteries of HEVs or EVs. LiMnPO4 composite such as LiMnPO4/ternary cathode materials could be most likely to be realized in the near future.