Fe2O3包覆对Li[Li0.2Ni0.13Co0.13Mn0.54]O2正极材料性能影响  

Effect of Fe2O3 coating on performance of Li[Li0.2Ni0.13Co0.13Mn0.54]O2 cathode material

作　　者：祝天喜 万柳 任丽[1] ZHU Tian-xi;WAN Liu;REN Li(Polymer Science and Engineering Research Institute,Hebei University of Technology,Tianjin 300130,China)

机构地区：[1]河北工业大学高分子科学与工程研究所

出　　处：《电源技术》2020年第2期160-164,共5页Chinese Journal of Power Sources

基　　金：国家自然科学基金(51203041)

摘　　要：采用化学沉淀法对共沉淀法制备的富锂锰基正极材料Li[Li0.2Ni0.13Co0.13Mn0.54]O2进行Fe2O3表面包覆改性。对所制备的材料进行X射线衍射光谱法(XRD)、扫描电子显微镜法(SEM)、透射电子显微镜法(TEM)、X射线光电子能谱法(XPS)和电化学分析等测试和表征,分析Fe2O3包覆对富锂锰基正极材料的结构、形貌和电化学性能的影响。结果表明,经Fe2O3包覆的正极材料都具有典型的α-NaFeO2层状结构,少许层状结构转变为尖晶石结构;Fe2O3包覆提高了材料的首次库仑效率和循环稳定性,Fe2O3包覆量质量分数为7%的Li[Li0.2Ni0.13Co0.13Mn0.54]O2呈现出的电化学性能最好,1 C下循环50次之后,容量保持率达90.16%。同时,交流阻抗结果表明Fe2O3包覆可有效减小材料的电荷转移阻抗并提高锂离子扩散系数。Lithium ion battery cathode material Li[Li0.2Ni0.13Co0.13Mn0.54]O2 synthesized by a co-precipitation method was modified by Fe2O3 through a chemical precipitation method. The structure, morphology and electrochemical performance of the prepared materials were characterized by XRD, SEM, TEM, XPS and electrochemical performance test. The results show that Fe2O3-coated cathode materials preform a typical layer structure of the α-NaFeO2 and a little layered structure transforms to spinel structure. The initial coulombic efficiency and cycling stability are significantly improved after the Fe2O3 coating, 7% Fe2O3-coated Li[Li0.2Ni0.13Co0.13Mn0.54]O2 delivers much higher capacity retention of 90.16% after 50 cycles at 1. The electrochemical impedance spectra show that the Fe2O3 coating reduces the charge transfer resistance and effectively improves the lithium ion diffusion coefficient.

关 键 词：锂离子电池 正极材料 Li[Li0.2Ni0.13Co0.13Mn0.54]O2 Fe2O3包覆 

分 类 号：TM912.9[电气工程—电力电子与电力传动]