正极材料LiNi_0.5Mn_1.5O₄的制备与性能

刘云建^{1, 2, 3}，刘志远²，陈效华²，陈龙³

(1. 江苏大学 材料科学与工程学院，江苏 镇江，212013；
2. 奇瑞汽车博士后科研工作站，安徽 芜湖，241009；
3. 江苏大学 汽车与交通工程学院，江苏 镇江，212013)

摘 要：采用共沉淀法制备Ni_0.25Mn_0.75(OH)₂，通过不同的烧结制度在高温下合成LiNi_0.5Mn_1.5O₄，并通过XRD和SEM对样品进行表征。研究结果表明：两段法和三段法合成的LiNi_0.5Mn_1.5O₄均具有良好的尖晶石结构和规则的几何外形。其首次放电容量分别为130和139 mA·h/g。80次循环后容量保持率分别为96.5%和97.5%。5C放电比容量分别为93和115 mA·h/g；两段法烧结样品的极化程度要大于三段法烧结样品的极化程度。

关键词：LiNi_0.5Mn_1.5O₄；烧结制度；电化学性能；循环伏安

Synthesis and performance of LiNi_0.5Mn_1.5O₄ cathodes

LIU Yun-jian^{1, 2, 3}, LIU Zhi-yuan², CHEN Xiao-hua², CHEN Long³

(1. School of Materials Science and Technology, Jiangsu University, Zhenjiang 212013, China;
2. Central Research Institute of Chery Automobile Co. Ltd., Wuhu 241009, China;
3. School of Automobile and Traffic Engineering, Jiangsu University, Zhenjiang 212013, China)

Abstract:LiNi_0.5Mn_1.5O₄ was synthesized by different sinter methods at high temperature with Ni_0.25Mn_0.75(OH)₂, which was synthesized by co-deposition. The sample was characterized by XRD and SEM. The results indicate that LiNi_0.5Mn_1.5O₄ synthesized by two-step and three-step have pure spinel structure and regular geometrical shape. The first-cycle discharge capacities are 130 and 139 mA·h/g, and the discharge capacities at 5C are 93 and 120 mA·h/g, respectively. The capacity retentions are 96.5% and 97.5% after 80 cycles, respectively. The polarization of two-step prepared sample is larger than that of three-step prepared sample.

Key words:LiNi_0.5Mn_1.5O₄; sinter method; electrochemical performance; cyclic voltammetry