( 1. 天津大學 化工學院 應(yīng)用化學系， 天津 300072;
2. 天津力神電池股份有限公司， 天津 300384)
摘 要: 采用有機溶劑醇熱法， 以異丙醇鋁為原材料對LiCoO2進行表面處理。通過XRD、 SEM對包覆前后正極材料的微觀結(jié)構(gòu)進行表征， 對包覆前后正極材料的電化學性能進行測試。結(jié)果表明： 包覆后正極材料的充放電效率明顯提高， 循環(huán)30次后容量保持率由包覆前的84.1%提高到包覆后的93.2%。 這歸因于包覆后LiCoO2表面形成的Al2O3或LiAlxCo1-xO2層，該層起到阻擋層的作用， 有效地抑制Co4+與電解液反應(yīng)，穩(wěn)定了LiCoO2結(jié)構(gòu)，提高了電化學循環(huán)性能。
關(guān)鍵字: 有機溶劑醇熱法; 表面修飾; 循環(huán)性能; 充放電效率
（ 1. School of Chemical Engineering and Technology,
Tianjin University, Tianjin 300072, China;
2. Tianjin Lishen Battery Joint-Stock Co.Ltd,
Tianjin 300384, China）
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 LiAlxCo1-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.
Key words: organic solvent alcohol-heating method； surface-modification； cycle performance; charge/discharge efficiency
