正极材料LiNi_(0.5)Mn_(0.5-x)Cr_xO_2的低温燃烧合成  

Low Temperature Combustion Synthesis of Cathode Materials LiNi_(0.5)Mn_(0.5-x)Cr_xO_2

作　　者：马真[1] 叶乃清[1] 温汉涛[1] 钟卓洪[1] 吴保明[1] 

机构地区：[1]桂林理工大学材料科学与工程学院有色金属及材料加工新技术教育部重点实验室,桂林541004

出　　处：《化学通报》2012年第9期856-859,共4页Chemistry

基　　金：广西自然科学基金项目(0832256);广西研究生教育创新计划项目(2011105960805M16)资助

摘　　要：以LiNO3、Ni(NO3)2.6H2O、50%Mn(NO3)2溶液、Cr(NO3)3.9H2O和尿素为原料,采用低温燃烧法合成了LiNi0.5Mn0.5-xCrxO2,研究了回火温度、回火时间、锂过量和掺铬量对正极材料电化学性能的影响。结果表明,采用低温燃烧法合成LiNi0.5Mn0.5-xCrxO2的优化条件为:回火温度850℃、回火时间16h、锂过量15%,适宜掺铬量x=0.02。在优化条件下合成的正极材料具有α-NaFeO2型层状结构、球状形貌和良好的电化学性能,以0.1C速率在2.5～4.6V之间充放电,首次放电容量为179.9mAh/g,第50次循环放电容量仍保有171.0mAh/g,容量保持率达到95.1%。The cathode materials LiNi0.5Mn0.5-xCrxO2 were synthesized by low temperature combustion process using LiNO3, Ni（ NO3 ） 2·6H2 O, 50% solution of Mn（ NO3 ） 2, Cr（ NO3 ） 3·9H2O and urea as starting materials. The effects of reheat temperature, reheat time, excess lithium and the amount of Cr substituting for Mn on the electrochemical performance of the cathode materials were investigated. The results indicated that the optimum preparation conditions of the cathode materials by low temperature combustion process were： to reheat the combustion product at 850℃ for 16h, with 15% excess lithium in the starting materials, and the optimum amount of Cr substituting for Mn is x = 0.02. The products synthesized under such conditions had α-NaFeO2-like layered structure, spherical morphology and excellent electrochemical performance. When charge-discharged at 0. 1C between 2. 5V and 4.6V, its discharge capacity was 179.9mAh/g in first cycle and remained 171.0mAh/g in the 50th cycle, with capacity retention of 95.1%.

关 键 词：锂离子电池 正极材料 LiNi0.5Mn0.5-xCrxO2 低温燃烧合成 

分 类 号：TM912[电气工程—电力电子与电力传动]