Er^(3+)掺杂LiFePO_4正极材料的制备与性能

Synthesis and Properties of Er-doped LiFePO_4 as Cathode Material

采用固相法合成了Er3+掺杂的试样,利用X射线衍射分析、四探针、电化学阻抗谱和充放电性能测试,探讨了掺杂位置及掺杂量对材料的晶体结构、电子电导率和电化学性能的影响.结果表明:铁位掺杂效果优于锂位掺杂,少于摩尔分数为3%的Er3+掺杂并未改变材料的晶体结构,但改善了材料的微观结构,电子电导率提高了4个数量级,1℃倍率下放电容量为103.47 mAh/g,比未掺杂试样提高了22.28%,Er3+掺杂改善了材料的比容量、循环性能及倍率性能.

The lithium-ion battery cathode material LiFePO4 doped by Er3＋ was synthesized through solid-state reaction.The X-ray diffraction analysis,four-probe method,electrochemical impedance spectroscopy and galvanostatic charge and discharge performance testing were used to study the position and the quantity of doping on the crystal structures,electronic conductivity and electrochemical performance of the samples.The results have shown that the effect of doping on Fe-site is better than Li-site.The Er3＋ dope of less than 3% does not affect the crystalline structure of the material but changes the microstructure of the samples when the electronic conductivity increases by four orders of magnitude.The discharge capacity of the sample is 103.47 mAh / g at the rate of 1.0 ℃,with an increase of 22.28% over the undoped samples.The doping of Er3＋ improves its specific capacity,cycling and rate electrochemical properties.