(吉首大学 生物资源与环境科学学院，吉首 416000)
摘 要: 采用流变相法结合控制热处理制备添加钇(Y)的LiNi0.5Mn1.5O4材料(LiNi0.5-0.5zMn1.5-0.5zYzO4)，研究钇添加量对LiNi0.5Mn1.5O4的结构、形貌、导电率以及电化学性能的影响。结果表明：添加适量的Y可抑制LiNi0.5Mn1.5O4颗粒的长大，稳定LiNi0.5Mn1.5O4的结构，提高材料的电导率，降低循环过程中的电化学极化，最终有效地提高LiNi0.5Mn1.5O4的循环性能和倍率性能。在研究范围内，添加量z为0.02时，材料LiNi0.49Mn1.49Y0.02O4具有最好的电化学性能。在0.2C放电时，LiNi0.49Mn1.49Y0.02O4的首次放电容量达到132.7 mA？h/g，经100次循环后，平均每次循环的容量衰减仅为0.011%。而在5.0C和10.0C放电时，LiNi0.49Mn1.49Y0.02O4仍显示出优异的倍率性能，首次放电容量仍达到0.2C放电时电容量的80.9%和76.9%，分别为107.3 mA？h/g和102.1 mA？h/g。
关键字: LiNi0.5Mn1.5O4材料；流变相法；高电压；钇添加；锂离子电池
（College of Biology and Environmental Science, Jishou University, Jishou 416000, China）
Abstract:LiNi0.5Mn1.5O4 materials with Y addition (LiNi0.5-0.5zMn1.5-0.5zYzO4) were prepared using rheological phase method combining with controlled heat-treatment. The effects of Y content on the structure, surface morphology, conductivity and electrochemical properties were investigated. The results show that the cycling performance and rate capability of LiNi0.5Mn1.5O4 materials will be improved effectively because that Y addition can suppress the growth of LiNi0.5Mn1.5O4 particles, stabilize the structure of LiNi0.5Mn1.5O4, increase the electronic conductivity of the electrode materials and decrease the electrochemical polarization in cycle. The materials with z of 0.02 show the best electrochemical properties. The first discharge capacity of LiNi0.49Mn1.49Y0.02O4 is more than 132.7 mA？h/g, an average capacity loss per cycle is 0.011% after cycling at 0.2C for 100 times. Even discharging at 5C and 10C, LiNi0.49Mn1.49Y0.02O4 still delivers a discharge capacity of 107.3 mA？h/g and 102.1 mA？h/g, equaling to 80.9% and 76.9% of the discharge capacity at 0.2C, suggesting excellent rate capability of LiNi0.5Mn1.5O4 with Y addition.
Key words: LiNi0.5Mn1.5O4 material; rheological phase method; high voltage; Y addition; lithium ion batteries
