含铝富锂正极材料xLi_2MnO_3·(1-x)LiNi_(0.8)Co_(0.15)Al_(0.05)O_2的制备和电化学性能  

Synthesis and electrochemical performance of Al-doped Li-rich layered xLi_2MnO_3·(1-x)LiNi_(0.8)Co_(0.15)Al_(0.05)O_2 cathode materials

作　　者：葛龙[1] 杨秀康[1] 余睿智[1] 王迪[1] 王先友[1] 舒洪波[1] 邹贵山[1] 鞠博伟[1] 温伟城 

机构地区：[1]湘潭大学化学学院,湘潭411105

出　　处：《中国有色金属学报》2015年第5期1236-1243,共8页The Chinese Journal of Nonferrous Metals

基　　金：湖南省重大科技成果转化项目(2012CK1006);湖南省战略性新兴产业项目(2013GK4018)

摘　　要：通过溶胶？凝胶法合成了含铝富锂正极材料xLi 2 MnO 3·（1？x）LiNi 0.8 Co 0.15 Al 0.05 O 2，探讨了化学组分（x=0.5，0.6，0.7，摩尔分数）和煅烧温度（850，900，950℃）对材料形貌、结构和性能的影响。采用XRD、SEM和电池充放电测试仪对材料进行物理表征和电性能测试。结果表明：所制备的材料具有典型的α-NaFeO 2层状结构。当x=0.6、煅烧温度为900℃时，所合成的材料具有较好的形貌和优良的电化学性能；在2.0-4.6 V、0.1C充放电条件下，0.6Li2MnO3·0.4LiNi0.8Co0.15Al0.05O2的首次放电比容量可达229.9 mA？h/g，且首次库仑效率为80.0%；在0.5C倍率下循环100次后，其放电比容量仍为192.7 mA？h/g，容量保持率达83.8%，显示了优良的循环性能。此外，材料显示了良好的倍率性能，在2.0C倍率下，其放电比容量仍为173.1 mA？h/g。Al-doped Li-rich layeredxLi 2MnO3·（1？x）LiNi0.8Co0.15Al0.05O2cathode materials were synthesized via sol-gel method, and the influence of chemical component （x=0.5, 0.6, 0.7, mole fraction） and calcination temperature （850, 900 and 950℃） on the morphology, structure and performance of the as-prepared materials were discussed. The physical characterization and electrochemical performance test of the as-prepared materials were conducted by means of XRD, SEM and electrochemical measurements. The results demonstrate that the prepared material has a typicalα-NaFeO2 layered structure, and thexLi2MnO3·（1？x）LiNi0.8Co0.15Al0.05O2exhibits the optimal electrochemical performance when the Li contentx is equals to 0.6 and sintering temperature at 900℃. The resultant 0.6Li2MnO3·0.4LiNi0.8Co0.15Al0.05O2sampleshows an high initial discharge capacity of 229.9 mA？h/g and coulomb efficiency of 80.0% for the first time when cycled in the voltage range of 2.0~4.6 V at 0.1C. In addition, the material exhibits good cycling stability with capacity retention of 83.8 % after 100 cycles at 0.5C. Furthermore, the material also shows good rate capability, delivering high discharge capacity of 173.1 mA？h/g at 2.0C.

关 键 词：锂离子电池 含铝富锂正极材料 溶胶-凝胶法 电化学性能 

分 类 号：TG139.7[一般工业技术—材料科学与工程]