Synthesis and electrochemical properties of nanosized carbon-coated Li_1?xLa_xFePO₄ composites

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• 作者：Dan Li ; Yudai Huang ; Dianzeng Jia ; Zaiping Guo and Shu-Juan Bao
• 关键词：LiFePO4 ; Lanthanum doping ; Carbon coating ; Lithium ion batteries ; Cathode materials
• 刊名：Journal of Solid State Electrochemistry
• 出版年：2010
• 出版时间：May, 2010
• 年：2010
• 卷：14
• 期：5
• 页码：889-895
• 全文大小：515.0 KB

文摘

Nanosized carbon-coated Li_1−3x La _x FePO₄ composites were synthesized using a fast, easy, microwave assisted, room-temperature, solid-state method. A lanthanum precursor was used to improve the electronic conductivity of LiFePO₄. The particle structure of the as-synthesized samples was observed using transmission electron microscopy. The results indicated that a uniform and continuous carbon layer was formed on the surface of Li_1−3x La _x FePO₄ particles. Electrochemical techniques, such as cyclic voltammetry, charge/discharge test, and electrochemical impedance spectroscopy were used to investigate the electrochemical performance of the samples. The results of electrochemical measurements revealed that the carbon coating and lanthanum doping provided an initial discharge capacity of 145 mA h/g with excellent rate capacity and long cycling stability. These advantages, coupled with the low cost, the high thermal stability, and the environmental friendliness of the raw materials, render Li_1−3x La _x FePO₄/C composites attractive for practical and large-scale applications.