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

Olivine-structured lithium manganese phosphate (LiMnPO_4) has the following advantages: excellent thermal stability, low cost, high safety and environmental benignity. Importantly, the theoretical energy density of LiMnPO_4 is about 20% higher than that of commercialized LiFePO_4 due to its higher Li~+ intercalation potential of 4.1 V (vs. Li~+/Li). Moreover, the high operating voltage of LiMnPO_4 is compatible with present non-aqueous organic electrolytes of lithium-ion batteries. Therefore, LiMnPO_4 is considered as a next generation cathode material for lithium-ion batteries. However, LiMnPO_4 suffers from poor electronic conductivity and low lithium diffusivity, resulting in its low discharge capacity and poor rate capability. And these intrinsic disadvantages hinder LiMnPO_4 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 LiMnPO_4 has the feasibility of applying in lithium batteries ofHEVs or EVs. LiMnPO_4 composite such as LiMnPO_4/ternary cathode materials could be most likely to be realized in the near future.