稀土掺杂合成离子电池正极材料LiMn_2O_4技术

Synthesis of rare earth doping cathode materials LiMn_2O_4 used for lithium ion batteries

锂离子电池由于工作电压高、自放电率低、能量密度大、循环寿命长而广泛应用于便携式设备。与锂钴氧相比, 锂锰氧以其价格低廉、对环境无污染是一种更有吸引力的锂离子动力电池正极材料, 但比容量低和高温循环性能差是长期以来困扰锂锰氧实现工业化的关键技术难题。我们采用机械化学活化法制备前驱体合成了多元稀土掺杂锂锰氧材料, 研究表明, 用稀土修饰的锂离子电池正极材料掺杂锂锰氧(LixMn2-y REzO4, 0.95≤x≤1.1, 0≤y≤0.3, 0≤z≤0.3), 具有较标准的尖晶石结构; 掺入合适的稀土元素后所合成的正极材料的比容量和循环性能都具有较大的改善, 同时也具有比较优良的高温性能。

Lithium-ion secondary batteries have been used widely in the field of portable device due to their high working voltage, low self-discharge rate, high energy density and long cycle life. The spinel LiMn_2O_4 is an more attractive cathode material for lithium ion batteries used for electric vehicle, because of its low-cost and lower toxicity compared with the layered oxides LiCoO_2. The key problem prohibiting spinel lithium manganese oxide from wider commercial use as a cathode for lithium batteries is the low capacity and the capacity fade at elevated temperature. The multiple rare earth doping lithium manganese oxide was synthesized by calcining the precursor prepared by mechanochemical method . The research results show that the cathode materials doped rare earth Li_xMn_~2-y RE_zO_4(0.95≤x≤1.2, 0≤y≤0.3, 0≤z≤0.2) have standard spinel structure; the specific capacity and cycle performance are improved; at the same time, the cathode materials have also excellent performance at elevated temperature.