摘要
以乙酸镁为镁源,用LiOH.H2O、Fe(NO3)3.9H2O、NH4H2PO4为原料通过水溶液法制备了掺杂Mg2+的LiFePO4/C正极材料。用XRD、SEM、恒流充放电测试、循环伏安(CV)和交流阻抗谱(EIS)方法,研究了Mg2+掺杂对LiFePO4/C的结构、形貌及电化学性能的影响。研究结果表明,Mg2+掺杂没有改变LiFePO4橄榄石型的结构;在0.1 C(1C=170 mAh.g-1)的充放电倍率下,Mg2+掺杂使正极材料首次放电比容量从153 mAh.g-1提高到159 mAh.g-1,经20循环次后,容量无损失;电化学交流阻抗显示,掺杂后材料阻抗Rct从463.1Ω减小到322.8Ω。
Mg2＋ doped LiFePO4/C cathode material was synthesized from LiOH- H2 O, Fe （ NO3 ） 3·9 H2 O, and NH4H2PO4 by an aqueous solution method with magnesium acetate as magnesium source. Influence of Mg2＋ doping on the structure, morphology and electrochemical properties of LiFePO4/C cathode mate- rial were tested by X-ray diffraction （XRD）, scanning electronmicroscopy （SEM）, Cyclic voltammetry （CV） ,EIS and galvanostatic charge-discharge test. The results showed Mg2＋ doping didn＇t change oli- vine structure of LiFePO4. At 0.1 C （ 1 C = 170 mAh/g） rate, a initial discharge capacity of Mg2＋doped material is 159 mAh/g, but that of undoped material is 153 mAh/g. After 20 cycles, the capacity of Mg2＋ doped material is almost no fading. Impedance Rot of the Mg2＋ doped material is 322.8Ω. while that of the undoped material is 463.1 Ω.
出处
《盐湖研究》
CSCD
2011年第4期53-57,72,共6页
Journal of Salt Lake Research
