Preparation of Cathode Material LiFePO_4/C Doped with Rare Earth Metal Ions by Sol-Gel Method and Study on Its Electrochemical Performance

A series of olivine structure LiFePO4/C cathode materials were synthesized by sol-gel method and doped with Gd3+,Ce4+,Sm3+and Tm3+at the stage of sol.The composition,morphology and electrochemical performance of LiFePO4/C were characterized by XRD,SEM and battery test,respectively.The results showed that the electrochemical performance of LiFePO4/C was downgraded with the doping of Sm3+and Tm3+,but the doping of 1%Gd3+or 2%Ce4+would improve the electrochemical performance of LiFePO4/C.The doping of1%Gd3+had the best effect,the initial discharge capacity of LiFePO4/C could reach 135.7mAh·g-1 at 0.1C.