钇掺杂LiFePO_4锂离子电池正极材料的制备与性能

Synthesis and Properties of Y-Doped LiFePO_4 as Cathode Material for Lithium-Ion Batteries

用固相法合成LiFe1-xYxPO4(x=0,0.01,0.02,0.03,0.04)锂离子电池正极材料,采用X射线衍射仪、扫描电子显微镜、粉末比电阻法和充放电性能测试表征材料的晶体结构、微观形貌、电子电导率和电化学性能。结果表明,少量的钇掺杂并未改变材料的晶体结构,但改善了材料的微观结构,提高其电子电导率,改善可逆容量和电化学性能。在10mA/g的电流密度下,LiFe0.97Y0.03PO4首次放电容量可达146.54mAh/g。

The lithium-ion battery cathode material LiFe1-xYxPO4（x=0,0.01,0.02,0.03,0.04） were synthesized by solid-state reaction.The crystalline structure,morphology,electronic conductivity and electrochemical properties of the samples were investigated by X-ray diffraction,scanning electron microscope,powder specific resistance method and galvanostatic charge-discharge tests,respectively.The results show that a small amount of Y3＋ doping does not change the crystalline structure of the material but considerably modifies the microstructure,thus increasing the electronic conductivity and improving reverse capacity and electrochemical properties.The sample of LiFe0.97Y0.03PO4 delivers an initial discharge capacity of 146.54 mAh/g at the current density of 10 mA/g.