摘要
采用固相法制备锆掺杂的钛酸锂Li4ZrxTi(5-x)O12(nTi∶nZr=25,50,75,100,125)材料,并优化了最佳的掺杂量(nTi∶nZr=100∶1)。对材料进行XRD、SEM、充放电和电化学阻抗谱测试结果表明:Zr掺杂使材料的晶胞参数略微增大,但并不影响立方尖晶石型Li4Ti5O12的颗粒度和形貌。在适量掺杂情况下,材料的电荷转移电阻明显减小,表现出了较好的倍率性能和循环稳定性。0.1 C时Li4Zr0.05Ti4.95O12的首次放电比容量为158.6 mAh/g,高于纯钛酸锂的放电比容量(142.9mAh/g),50次循环后的容量保持率为97.6%;1.0 C和3.0 C倍率下首次放电比容量为137.8,103.2 mAh/g,比纯钛酸锂分别提高了18.3,23.1 mAh/g,容量保持率分别为98.1%和93.3%。
A series of Li4ZrxTi（5-x）O12 （n_Ti：n_Zr=25,50,75,100,125） were prepared by solid-state reaction. The optimized zirconium doping amount is n_Ti： n_Zr=100 ： 1. XRD, SEM, charge-discharge tests and AC impedance techniques were used to investigate the effects of zirconium doping. Results show that the lattice parameter increases with the increase amount of Zr-doping. But there is nearly no effects on the particle size and feature. Charge transfer resistance of the prepared materials decreases with the appropriate doping amount, and show enhanced rate performance and cycling stability. The discharge specific capacity of Li4Zr0.05Ti4.95O12 at 0.1 C reaches 158.6 mAh/g, which is higher than that of the pure Li4Ti5O12（ 142.9 mAh/g ）. And the capacity retention is 97.6% after 50 cycles. At 1 C and 3 C, the discharge specific capacities are 137.8 mAh/g and 103.2 mAh/g, respectively, which increase 18.3 mAh/g and 23.1 mAh/g than that of the pure Li4Ti5O12. And the capacity retention is 98.1% and 93.3%.
出处
《电源技术》
CAS
CSCD
北大核心
2013年第6期924-927,共4页
Chinese Journal of Power Sources
基金
国家自然科学基金(21001041)
河南省教育厅自然科学基础研究计划项目(2010B430017)
关键词
LI4TI5O12
固相法
锆掺杂
电化学性能
Li4Ti5O12
solid-state synthesis
zirconium doping
electrochemical properties
