固相法合成LiFePO₄/C正极材料的电化学性能

来源期刊：中国有色金属学报2010年第12期

论文作者：王国宝 王先友 舒洪波 王英平 杨顺毅 刘修明 裴斧 王雁生 安红芳 郑丽萍 陈权启

文章页码：2351 - 2356

关键词：LiFePO₄/C复合材料；铁源；锂离子电池；正极材料

Key words：LiFePO₄/C composite; iron source; lithium ion battery; cathode material

摘    要：以廉价原材料FeSO₄·7H₂O为铁源，以蔗糖为碳源，采用固相法合成了锂离子电池正极材料——LiFePO₄/C复合材料。用X射线衍射(XRD)、扫描电镜(SEM)和电化学测试技术对不同铁源合成的LiFePO₄/C复合材料的结构、形貌和电化学性能进行研究。结果表明：合成的样品具有均一的橄榄石型结构，以FeSO₄·7H₂O为铁源合成的LiFePO₄/C复合材料的循环性能和高倍率放电性能均优于以FeC₂O₄·2H₂O为铁源合成的LiFePO₄/C复合材料的；由FeSO₄·7H₂O合成的LiFePO₄/C复合材料的5C倍率放电比容量为105.9 mA·h/g，经循环30次后，容量仍高达105.2 mA·h/g。

Abstract: The lithium ion battery cathode material LiFePO₄/C composite was prepared by a solid-state method using the low cost FeSO₄·7H₂O as iron source and sucrose as carbon source. The structure, morphology and electrochemical performance of the LiFePO₄/C samples prepared with different iron sources were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemistry techniques. The results show that the resultant LiFePO₄/C has homogeneous olivine structure. And the capacity and cycle ability of LiFePO₄/C prepared from FeSO₄·7H₂O are higher than that of LiFePO₄/C composite synthesized by a traditional solid-state method using FeC₂O₄·2H₂O as iron source. The capacity is 105.9 mA·h/g at 5C rate and remained 105.2 mA·h/g after 30 cycles.