关键词: 动力锂离子电池, 高能量密度, 磷酸锰锂, 正极材料

Abstract: 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, LiMnPO₄ 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 including 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.

Key words: lithium-ion batteries, high-energy density, lithium manganese phosphate, cathode material