(湘潭大學 化學學院 環(huán)境友好化學與應用教育部重點實驗室，湘潭 411105)
摘 要: 以廉價原材料FeSO4·7H2O為鐵源，以蔗糖為碳源，采用固相法合成了鋰離子電池正極材料——LiFePO4/C復合材料。用X射線衍射(XRD)、掃描電鏡(SEM)和電化學測試技術對不同鐵源合成的LiFePO4/C復合材料的結構、形貌和電化學性能進行研究。結果表明：合成的樣品具有均一的橄欖石型結構，以FeSO4·7H2O為鐵源合成的LiFePO4/C復合材料的循環(huán)性能和高倍率放電性能均優(yōu)于以FeC2O4·2H2O為鐵源合成的LiFePO4/C復合材料的；由FeSO4·7H2O合成的LiFePO4/C復合材料的5C倍率放電比容量為105.9 mA∙h/g，經(jīng)循環(huán)30次后，容量仍高達105.2 mA∙h/g。
關鍵字: LiFePO4/C復合材料；鐵源；鋰離子電池；正極材料
synthesized by solid-state reaction
PEI Fu, WANG Yan-sheng, AN Hong-fang, ZHENG Li-ping , CHEN Quan-qi
（Key Laboratory of Environmentally Friendly Chemistry and Applications,
Ministry of Education, School of Chemistry, Xiangtan University, Xiangtan 411105, China）
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.
Key words: LiFePO4/C composite; iron source; lithium ion battery; cathode material
