Effect of rare earth ions doping on properties of LiFePO4/C cathode material

• Published in: Journal of rare earths Vol. 32; no. 9; pp. 895 - 899
• Main Author: 王丽 焦昌梅 梁广川 赵南南 王亚勉 李琳慈
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2014
• Subjects: cathode material; LiFePO4; lithium-ion battery; rare earth ions doping; X射线衍射; 扫描电子显微镜; 材料性能; 正极材料; 电化学性能; 磷酸铁锂; 稀土离子掺杂; rare earth ions doping; cathode material; lithium-ion battery; LiFePO4
• ISSN: 1002-0721; 2509-4963
• DOI: 10.1016/S1002-0721(14)60160-5

LiFe0.99RE0.01PO4/C cathode material was synthesized by solid-state reaction method using FeC2O4-2H2O, Li2CO3, NH4H2PO4, RE（NO3）3·nH2O as raw materials and glucose as a carbon source. The doping effects of rare earth ions, such as La3＋, Ce3＋, Nd3＋, on the structure and electrochemical properties of LiFePO4/C cathode material were systematically investigated. The as-prepared samples were characterized by means of X-ray diffraction （XRD）, scanning electron microscopy （SEM） and particle size analysis. The electrochemical properties were investigated in terms of constant-current charge/discharge cycling tests. The XRD results showed that the rare earth ions doping did not change the olivine structure of LiFePO4, and all the doped samples were of single-phase with high crystallinity. SEM and particle size analysis results showed that the doping of La3＋, Ce3＋ and Nds＋ led to the decrease of particle size. The electrochemical results exhibited that the doping of La3＋ and Ce3＋ could improve the high-rate capability of LiFePO4/C cathode material, among which, the material doped with 1% Ce3＋ exhibited the optimal electrochemical properties, whose specific discharge capacities could reach 128.9, 119.5 and 104.4 mAh/g at 1C, 2C and 5C rates, respectively.