Rb掺杂Li4Ti5O12作为锂离子电池负极材料的合成及电化学性能

Synthesis and Electrochemical Performances of Rb-Doped Li4Ti5O12 as Anode Material for Lithium-Ion Batteries

合成了不同Rb掺杂量的钛酸锂(Li4-xRbxTi5O12;x=0.010,0.015,0.020)作为锂离子电池的负极材料。测试结果显示,Rb离子掺杂有效增强了钛酸锂的电子电导率。相同的测试条件下,相比于未掺杂样品和高Rb含量掺杂样品(x=0.015,0.020),适量的Rb掺杂钛酸锂(Li3.99Rb0.01Ti5O12;x=0.010)表现出最优的电化学性能。Li3.99Rb0.01Ti5O12材料表现出161.2 mA∙h/g的初始容量,且在1 C下经过1000次循环后容量保持率可达90.9%。此外,全电池Li3.99Rb0.01Ti5O12//LiFePO4在0.5 C条件下首次放电容量为144 mA∙h/g,经过150次循环后,容量保持率为78.8%。

Rb-doped lithium titanates with different doping levels(Li4-xRbxTi5O12;x=0.010,0.015,0.020)as anode materials for lithium-ion batteries were synthesized.Results showed that the electronic conductivity of lithium titanates was enhanced by Rb doping.The low Rb-doping level sample(Li3.99Rb0.01Ti5O12;x=0.010)showed better electrochemical performances than those with higher doping levels(x=0.015,0.020)and neat lithium titanate prepared under the same conditions.Li3.99Rb0.01Ti5O12 with the optimized Rb-doping level delivered an initial capacity of 161.2 mA∙h/g with capacity retention of 90.9%after 1000 cycles at 1 C.The full cell of Li3.99Rb0.01Ti5O12//LiFePO4 delivered a discharge capacity of 144 mA∙h/g,retaining 78.8%of the initial capacity after 150 cycles at 0.5 C.