LiFePO_4-LiMn_2O_4混合正极材料对电池性能的影响

Effect of mixed LiFePO_4-LiMn_2O_4 cathode material on the performance of batteries

通过微波反应合成具有亚微米尺寸的LiFePO4/C复合材料,并将LiFePO4/C和通过高温固相法合成的LiMn2O4按照一定的质量比均匀混合用作锂离子电池正极材料。电池充放电测试表明电池的循环性能随着LiFePO4量的增加逐渐变好,当LiFePO4与LiMn2O4的质量比在3∶2时电池具有较好的循环性能和较高的比功率。交流阻抗测试表明二者混合试用可以有效地降低电极过程的电荷传递电阻。最后分析了循环性能提高的原因。

The different proportional mixtures with sub-micro-sized LiFePO4/C synthesized by microwave radiation processing and LiMn2O4 prepared by solid-state method were used as cathode materials for lithium ion battery. The results of charge-discharge tests show that the cyclic performance becomes better with the increase of LiFePO4/C. The battery has good cyclic capability and higher power density when the rate of LiFePO4 and LiMn2O4 is 3 ： 2. The electrochemical impedance spectroscopy （EIS） measurements indicate that charge transfer resistance （Rct） can be reduced when they are mixed as cathode material. At last the mechanism that the improvement of cyclic performance was discussed,