锂离子电池正极材料Li_(0.97)Re_(0.01)FePO_4的合成及性能

Synthesis and Performance of Cathode Materials Li_(0.97)Re_(0.01)FePO_4 for Lithium Ion Batteries

采用固相反应法合成了锂离子电池正极材料Li0.97Re0.01FePO4(Re=Er,Y,Gd,Nd,La),采用X射线衍射、恒电流充放试验对掺杂试样的微观结构和电化学性能进行测试。试验结果表明:掺杂稀土金属离子对LiFePO4的晶体结构没有影响,与LiFePO4相比,掺杂Er3+,Y3+,Gd3+的试样具有优良的循环性能和倍率性能,而掺杂Nd3+,La3+的试样的循环性能和倍率性能较差。掺杂试样中,Li0.97Gd0.01FePO4的电化学性能最佳,在C/10和1C(1C=120 mA.g-1)倍率下放电容量均最大。

Cathode materials Li0.97Re0.01FePO4 for Lithium ion batteries are synthesized by solid-state reaction method （Re=Er, Y, Gd, Nd, La）. The microstructure and electrochemical performance of the doping samples are tested by X-ray diffraction （XRD） and charge-discharge experiments. The experimental results show that doping with rare-earth ions has no effect on microstructure of LiFePO4. Compared with LiFePO4, the samples doping with Er^3＋, Y^3＋, Gd^3＋ possess excellent cycling capability and rate performance, but the samples doping with Nd^3＋, La^3＋ have bad cycling capability and rate performance. In doping samples, Li0.97Re0.01FePO4 exhibits the most excellent electrochemical performance and its discharge capacities both are the biggest at C/10 and 1C ratio.