Effect of CeO2-coating on the electrochemical performances of LiFePO4/C cathode material
Effect of CeO2-coating on the electrochemical performances of LiFePO4/C cathode material
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DOI：
10.1016/j.electacta.2011.03.141
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发表时间：
2011-06
影响因子：
6.6
通讯作者：
Jingwen Yao;Feng Wu;X. Qiu;Ning Li;Yuefeng Su
中科院分区：
文献类型：
--
作者：
Jingwen Yao;Feng Wu;X. Qiu;Ning Li;Yuefeng Su
重点：→首次研究了CeO 2涂层对LiFePO 4/C低温性能的影响。→涂层阴极在高倍率和低温下表现出更好的容量。→ CeO 2涂层降低了电极极化，提高了电荷转移反应活性。-翻译后摘要：CeO 2涂层上的LiFePO 4/C正极材料的效果进行了研究。采用XRD、SEM、TEM等手段对合成粉体的结构和形貌进行了表征，并通过循环伏安（CV）、交流阻抗（EIS）和恒流充放电测试对合成粉体的室温和低温电化学性能进行了评价。研究发现，纳米CeO 2颗粒分布在LiFePO 4表面，没有破坏块体材料的晶体结构。CeO 2包覆的LiFePO 4/C阴极材料显示出改善的锂嵌入/提取容量和电极动力学，特别是在高速率和低温下。在-20 deg.在0.1C倍率下放电容量为99.7mAh/g，在不同充放电倍率下循环30次后容量保持率为98.6%。结果表明，表面处理是提高锂离子电池正极材料综合性能的有效途径。
Highlights:→ The first study the effect of CeO2 coating on LiFePO4/C at low temperature.→ Coated cathode shows improved capacities at high rates and low temperature.→ CeO2-coating decreases electrode polarization and increases charge-transfer reaction activity.-Abstract: The effect of CeO2 coating on LiFePO4/C cathode material has been investigated. The crystalline structure and morphology of the synthesized powders have been characterized by XRD, SEM, TEM and their electrochemical performances both at room temperature and low temperature are evaluated by CV, EIS and galvanostatic charge/discharge tests. It is found that, nano-CeO2 particles distribute on the surface of LiFePO4 without destroying the crystal structure of the bulk material. The CeO2-coated LiFePO4/C cathode material shows improved lithium insertion/extraction capacity and electrode kinetics, especially at high rates and low temperature. At-20 deg. C, the CeO2-coated material delivers discharge capacity of 99.7 mAh/g at 0.1 C rate and the capacity retention of 98.6% is obtained after 30 cycles at various charge/discharge rates. The results indicate that the surface treatment should be an effective way to improve the comprehensive properties of the cathode materials for lithium ion batteries.