【摘要】 以La3+为Li位掺杂离子、Mg2+为Fe位掺杂离子,采用液相法合成双位掺杂的Li1-xLaxFe1-yMgyPO4/C(0≤x<1,0≤y<1)锂离子电池复合正极材料。通过X射线衍射法(XRD)和扫描电子显微镜法(SEM)研究材料的结构及形貌,恒流充放电测试电化学性能,考察Li1-xLaxFe1-yMgyPO4/C室温和低温电化学性能。结果表明:适量的La、Mg离子掺杂并未改变材料的结构;当La3+离子掺杂量为1%(摩尔分数)、Mg2+离子掺杂量为10%(摩尔分数)时,Li1-xLaxFe1-yMgyPO4/C的电化学性能最优。室温下,0.1 C首次充放电比容量达到155 m Ah/g。-20℃时,1 C、5 C、10 C较大倍率下首次充放电比容量为69、68、69 m Ah/g,低温下不同放电倍率下稳定性良好,拥有优异的低温循环稳定性。更多还原

【Abstract】 The multiple doping lithium ion battery composite cathode material Li1-xLa xFe1-yMgyPO4/C(0≤x<1, 0≤y <1) was synthesized via a solution route using La3+ and Mg2+ as dopant ions.The samples were characterized by XRD,SEM and galvanostastic charge-discharge test,with the emphasis on low-temperature electrochemical performance.The results show that the samples are pure olive phase and the Li1-xLa xFe1-yMgyPO4/C has the best electrochemical performance when the La doping amount is 1% and the Mg is 10%.The initial discharge capacity of the sample delivers 155 mAh/g at 0.1 C at room temperature.At-20 ℃,the sample also keeps 69,68 and 69 mAh/g at 1 C,5 C and 10 C.In addition,it shows excellent low-temperature cycle stability at different rates.更多还原