锂离子二次电池正极材料LiAl_yCo_(0.2)Ni_(0.8-y)O_2的合成及其电化学性能研究  

Preparation and Electrochemical Properties Studies of Al-doped LiNi_(0.8)Co_(0.2)O_2 Cathode Materials

作　　者：江卫军[1] 其鲁[1] 柯克[1] 王银杰[1] 晨晖 

机构地区：[1]北京大学化学与分子工程学院应用化学系新能源材料与技术实验室,北京100871

出　　处：《无机化学学报》2003年第12期1280-1284,共5页Chinese Journal of Inorganic Chemistry

摘　　要：用固相反应法合成了锂离子二次电池正极材料LiAlyCo0.2Ni0.8-yO2(y=0,0.001,0.005,0.01,0.03),采用XRD、SEM、ICP-AES、差分计时电位法和充放电循环等对合成的材料的物理化学性质以及电化学性能进行了测试分析。结果表明所合成的产物均为α-NaFeO2型的层状结构,产物无杂质相,产物的表面形貌规则,颗粒大小均匀。实验结果证明经过Al掺杂后的材料的放电电压平台有所提高,容量也有所上升。并且随着Al含量的增加,材料在电化学充放电过程的结构稳定性在上升,因此电化学稳定性得到了提高。实验结果还表明低含量Al元素的掺杂既提高了LiNi0.8Co0.2O2的放电容量,又提高了其循环可逆性,使材料的容量保持率显著提高。Al-doped LiAlgammaNi0.8-gammaCo0.2O2(gamma=0-001, 0.005, 0.01, 0.03) cathode materials were synthesized by the solid-state method. The materials were characterized by XRD, SEM, ICP-AES, differential chronopotentiometry and galvanostatic cycling. The results showed that the products, without impurities, had typical alpha-NaFeO2 layered structures, uniform morphology and moderate grain size. The discharge voltage plateau as well as discharge capacity of the Al-doped materials was higher than that of the undoped ones. And with the amount of Al increasing to a certain extent, the structure stability of the materials was improved during the charge-discharge process. Therefore the electrochemical stability was improved. The results also indicated that low Al-dopant could not only improve the cyclability but also gain high discharge capacity.

关 键 词：锂离子二次电池 正极材料 LiAlyCo0.2Ni0.8-yO2 合成 电化学性能 AL掺杂 氧化钴锂 

分 类 号：TM912.2[电气工程—电力电子与电力传动]