稀土离子掺杂对锂离子电池正极材料Li_3V_2(PO_4)_3/C的影响研究

Influence of doped rare earth element on lithium ion battery anode material Li_3V_2(PO_4)_3/C

讨论了稀土Gd^(3+)、La^(3+)掺杂对溶胶-凝胶法合成正极材料单斜晶型Li_3V_2(P0_4)_3/C的影响。通过XRD、SEM、EDS、恒流充放电、CV和EIS等技术对材料的微观结构、颗粒形貌和电化学性能进行分析,研究了2种稀土元素不同掺杂量对材料结构和电化学性能的影响。结果表明,相对纯相Li_3V_2(PO_4)_3/C,适量的稀土离子掺杂能减小晶粒,提高电化学性能,并且掺杂的稀土Gd^(3+)在x=0.03时具有最好的电化学性能,室温条件,在3~4.3V充放电平台下,以0.1C首次放电比容量达到126.7mAh/g,第50次循环的放电比容量仍有103.6mAh/g,容量保持率为81.8%。

The effect of rare earth elements Gd^（3＋）and La^（3＋）on the anode material Li3V2（PO4）3/C prepared by solgel method was discussed.By XRD,SEM,EDS,constant current charge discharge,CV,and EIS,the material microstructure,particle morphology and electrochemical performance were analyzed.And the effect of two kinds of rare earth elements doped with different amount on the structure and electrochemical properties of material was studied.The results showed that compared LVP/C pure phase,the doping of appropriate amount can decrease the grain and improved the electrochemical performance.And when Gd^（3＋）doping amount x=0.03,the material had the best electrochemical performance.Under the room temperature at 3~4.3 Vcharging and discharging platform with 0.1 C,the initial specific discharge capacity reached126.7 mAh/g.After 50 cycles the discharge specific capacity was still 103.6 mAh/g.And the retention rate can be still81.8%.