阴极材料Li_1.2Cr_0.4Mn_0.4O₂的制备及其电化学性能

阴极材料Li 1.2 Cr 0.4 Mn 0.4 O 2 的制备及其电化学性能 Preparation and Electrochemical Property of Li 1.2 Cr 0.4 Mn 0.4 O 2 as Cathode 赵勇 ZHAO Yong 1 2 first-author 王敏 WAN Min 1 2 吴智远 WU Zhi-yuan 1 2 武汉大学化学与分子科学学院 武汉大学化学与分子科学学院 College of Chemistry and Molecular Sciences, Wuhan University College of Chemistry and Molecular Sciences, Wuhan University 武汉大学化学与分子科学学院,湖北,武汉,430072 武汉大学化学与分子科学学院,湖北,武汉,430072 采用溶胶凝胶法制备层状富锂Li1.2Cr0.4Mn0.4O2阴极材料.研究煅烧温度对阴极材料的结构,及电化学性能的影响.利用X 射线衍射（XRD）、扫描电镜（SEM）、X 射线光电子能谱（XPS）等方法对阴极材料的晶体结构、充放电过程中价态的变化、表观形貌、粒径大小等进行分析.结果表明850 ℃时煅烧后的阴极材料层状结构明显,电化学性能优良.以小放电速度进行恒流（10 mA/g）充放电循环,首次放电比容量可以达到280 mAh/g,经过40次循环后仍可以达到190 mAh/g.研究发现在整个充放电过程中Mn始终保持+4价态, 部分Cr作为活性离子价态在+6和+3之间可逆变化.Li1.2 Cr0.4 Mn0.4 O2 经过镀银后以大放电速度进行恒流（80 mA/g）放电可以达到100 mAh/g的比容量. Layered Li 1.2 Cr 0.4 Mn 0.4 O 2 was derived from sol-gel method as cathode. The effects of different calcination temperatures on structure and electrochemical property were studied. Crystalline structure, changes of valence during charge and discharge, morphology of particles, crystalline size were investigated by X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy. It is shown that Li 1.2 Cr 0.4 Mn 0.4 O 2 treated at 850 ℃ exhibits excellently layered structure and electrochemical property. Chromium is changing reversibly between +6 and +3 during charge and discharge, but Manganese remains +4. It can exhibit a perfect initial discharge capacity of 280 mAh/g at a little current rate（10 mA/g）, also keeping capacity of 190 mAh/g after 40 th cycle. This material dealing with Ag can exhibit good capacity of 100 mAh/g at a large current rate（80 mA/g）. 溶胶凝胶法 富锂层状阴极材料 Li1.2Cr0.4Mn0.4O2 sol-gel method layered rich lithium cathode Li1.2Cr0.4Mn0.4O2 TM911 国家自然科学基金资助项目（20077020） 2005-02-01 2021-04-01 2