Rb掺杂Li4Ti5O12作为锂离子电池负极材料的合成及电化学性能

合成了不同Rb掺杂量的钛酸锂（Li_4-xRb_xTi₅O₁₂; 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（Li_3.99Rb_0.01Ti₅O₁₂; x = 0.010）表现出最优的电化学性能。Li_3.99Rb_0.01Ti₅O₁₂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Li_3.99Rb_0.01Ti₅O₁₂ // 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%。

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

Rb-doped lithium titanates with different doping levels (Li_4-xRb_xTi₅O₁₂; 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 (Li_3.99Rb_0.01Ti₅O₁₂; 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. Li_3.99Rb_0.01Ti₅O₁₂ with the optimized Rb-doping level delivered an initial capacity of 161.2 mA∙h/g with capacity retention of 90.9% after 1 000 cycles at 1 C. The full cell of Li_3.99Rb_0.01Ti₅O₁₂//LiFePO₄ delivered a discharge capacity of 144 mA∙h/g, retaining 78.8% of the initial capacity after 150 cycles at 0.5 C.