Al^(3+)掺杂0.5Li_2MnO_3-0.5LiCo_(1/3)Ni_(1/3)Mn_(1/3)O_2正极材料的研究  

Improved Electrochemical Properties of Al^(3+)-doped 0.5Li_2MnO_3-0.5LiCo_(1/3)Ni_(1/3)Mn_(1/3)O_2 Cathode for Lithium Ion Batteries

作　　者：张文华[1,2] 何巍[2] 裴锋[1] 伍发元[1] 毛荣军[1] 艾新平[2] 杨汉西[2] 曹余良[2] 

机构地区：[1]江西省电力科学研究院,南昌330096 [2]武汉大学化学与分子科学学院,武汉430072

出　　处：《无机材料学报》2013年第11期1261-1264,共4页Journal of Inorganic Materials

基　　金：国家电网公司课题资助;国家973计划(2009CB220103)~~

摘　　要：采用聚合热解法制备了掺入3%Al3+的富锂锰基Li[Li0.2Co0.13Ni0.13Mn0.51Al0.03]O2材料,经过X射线衍射(XRD)、扫描电镜(SEM)实验表明,掺入3%Al3+样品仍然保持层状结构,没有观察到杂质相的存在。在2.0~4.8 V范围内进行恒流充放电测试表明,掺Al3+样品在30 mA/g的电流密度下,首周充放电比容量可达349.1和303.8 mAh/g(首次库仑效率87%);在100 mA/g的电流密度下,100次循环后,容量保持率为91.7%,显示出高的循环稳定性。这些结果表明掺杂Al3+能够在一定程度上提高富锂氧化物材料层状结构的稳定性,为发展高容量和高稳定性正极材料提供一种新途径。The lithium-rich cathode materials Li[Li0.2Co0.13Ni0.13Mn0.51Al0.03]O2 doped with 3% Al3＋ were synthesized by a polymer-pyrolysis method. The structure and morphology of the as-prepared material were characterized by X-ray diffraction （XRD）, scanning electron microscope （SEM）. The structural analyses exhibit that the Al3＋-doped sample maintains the layered structure of the Li-rich oxide material and no impurity is detected in XRD patterns. The charge-discharge tests show that the Al3＋-doped sample has a high charge/discharge capacity of 349.1/303.8 mAh/g （initial coulombic efficiency of 87%） at current density of 30 mA/g. Additionally, Al3＋-doped sample also exhibits excellent cyclability with 91.7% capacity retention over 100 cycles. The results demonstrate that Al3＋ doping is favorable to maintain the structural stability of the layered structure during the electrochemical lithium insertion/extraction, so as to provide a promising route to develop cathode materials with high capacity and stability.

关 键 词：锂离子电池 Li2MnO3-LiMO2 Al3+掺杂 正极材料 

分 类 号：O64[理学—物理化学]