(湘潭大學(xué) 化學(xué)學(xué)院 環(huán)境友好化學(xué)與應(yīng)用教育部重點(diǎn)實(shí)驗(yàn)室，湘潭 411105)
摘 要: 采用高溫固相法合成Ni2+、Mn2+共摻雜的LiFe0.95Ni0.02Mn0.03PO4/C正極材料。通過X射線衍射(XRD)、掃描電鏡(SEM)、電化學(xué)阻抗譜(EIS)和電化學(xué)測試技術(shù)等研究材料的結(jié)構(gòu)、形貌和電化學(xué)性能。結(jié)果表明：Ni2+和Mn2+共摻雜后的LiFe0.95Ni0.02Mn0.03PO4/C材料仍然具有LiFePO4/C橄欖石型晶體結(jié)構(gòu)，且摻雜后材料的放電比容量和循環(huán)性能都得到顯著改善。在0.1C和1C下放電時(shí)，未摻雜LiFePO4/C的首次放電比容量僅分別為153和140 mA∙h/g，而Ni2+、Mn2+共摻雜的LiFe0.95Ni0.02Mn0.03PO4/C材料首次放電比容量分別為165和145 mA∙h/g，且在1C下循環(huán)100次后容量保持率仍然為97.6%。
關(guān)鍵字: 鋰離子電池；正極材料；金屬離子共摻雜；電化學(xué)性性能
YANG Xiu-kang, BAI Yan-song, WEI Qi-liang
（School of Chemistry, Key Laboratory of Environmentally Friendly Chemistry and Applications,
Ministry of Education, Xiangtan University, Xiangtan 411105, China）
Abstract:LiFe0.95Ni0.02Mn0.03PO4/C cathode material co-doped by Ni2+ and Mn2+ ions, was prepared by high temperature solid phase method. The structure, morphology and electrochemical properties of the as-prepared material were characterized by XRD, SEM, EIS and charge-discharge methods. The results show that the as-prepared LiFe0.95Ni0.02Mn0.03PO4/C keeps the olivine structure of LiFePO4/C, and the discharge specific capacity and cyclic stability are obviously enhanced. The initial discharge capacities of LiFePO4/C without doping are only 153 and 140 mA∙h/g at 0.1C and 1C, respectively. While the initial discharge capacities of LiFe0.95Ni0.02Mn0.03PO4/C co-doped with Ni2+ and Mn2+ are 160 and 145 mA∙h/g at 0.1C and 1C, respectively. Besides, the capacity retention still has 97.6% after 100 cycles.
Key words: lithium-ion battery; cathode material; metal ions co-doping; electrochemical properties
