双相碳改性硅酸铁锂正极材料研究  

Research on Two-Phase Carbon Modified Li_2FeSiO_4 as Cathode Material

作　　者：段松[1] 张露露[1] 杨学林[1] 彭刚[1] 黄云辉[2] 覃磊[1] 李明[1] 倪世兵[1] 

机构地区：[1]三峡大学材料与化工学院,宜昌443002 [2]华中科技大学材料科学与工程学院,武汉430074

出　　处：《无机化学学报》2014年第2期345-352,共8页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.51302153;51302152;51272128);湖北省教育厅重点(No.D20131303);湖北省杰出青年基金(No.2011CDA093);宜昌市科学技术研究与开发项目(No.A2011-302-8);三峡大学人才科研启动基金(No.KJ2012B043)资助项目

摘　　要：以活化的天然石墨为碳源,采用固相辅助回流法成功合成了双相碳改性的Li2FeSiO4复合材料。采用XRD、SEM、HRTEM和Raman光谱分析了Li2FeSiO4/(C+G)复合材料的物相、形貌及其微观结构;并研究了活化石墨用量对Li2FeSiO4/(C+G)复合材料的电化学性能的影响。结果表明:活化石墨以石墨微晶和无定形碳的形态共存于Li2FeSiO4/(C+G)材料中,活化石墨用量为5%时所得样品的首次放电容量较高(170.3 mAh·g-1),循环50次后其容量保持率为88.7%,表现出了良好的电化学性能。Two-phase carbon modified Li2FeSiO4 composites （Li2FeSiO4/（C＋G）） were synthesized via solid-state reaction assisted with refluxing. Activated natural graphite was chosen as carbon source. The phase and the microstructure of Li2FeSiO4/（C＋G） were characterized by X-ray diffraction （XRD）, scanning electron microscope （SEM）, transmission electron microscopy （TEM） and Raman spectrometry （Raman）. The effect of activated graphite content on the electrochemical performance of Li2FeSiO4/（C＋G） was also investigated. The results show that activated graphite exists in Li2FeSiO4/（C＋G） samples in the form of amorphous carbon as well as graphite crystallite. Li2FeSiO4/（C＋G） composite prepared with 5wt% activated graphite achieved the excellent electrochemical performance with a higher initial discharge capacity of 170.3 mAh·g-1 and with a capacity retention ratio of 88.7% after 50 cycles.

关 键 词：正极材料 硅酸铁锂 活化石墨 电化学性能 

分 类 号：O613.72[理学—无机化学] O614.122[理学—化学]