【摘要】 采用有机溶剂醇热法,以异丙醇铝为原材料对LiCoO2进行表面处理。通过XRD、SEM对包覆前后正极材料的微观结构进行表征,对包覆前后正极材料的电化学性能进行测试。结果表明:包覆后正极材料的充放电效率明显提高,循环30次后容量保持率由包覆前的84.1%提高到包覆后的93.2%。这归因于包覆后LiCoO2表面形成的Al2O3或LiAlxCo1-xO2层,该层起到阻挡层的作用,有效地抑制Co4+与电解液反应,稳定了LiCoO2结构,提高了电化学循环性能。更多还原

【Abstract】 The organic solvent alcohol-heating method was used to modify LiCoO₂ cathode material’s surface with aluminium isopropoxide. The structures of surface-modified LiCoO₂ cathode material were characterized with X-ray diffraction（XRD） and scanning electron microscope（SEM）.The electrochemical measurement results show that the charge/discharge efficiency of coated LiCoO₂ is improved significantly and the capacity retention is increased from 84.1% to 93.2% after 30 cycle times. The improvements are attributed to the Al₂O₃ or solid solution LiAl_xCo_1-xO₂ layer on the LiCoO₂ surface. The coating layer is effective in stopping reactions of Co⁴⁺ ions with electrolyte, and stabilizes the structure of LiCoO₂, so improving the electrochemical cycle performance.更多还原