【摘要】 以电解二氧化锰和碳酸锂为原料用高温固相法合成了尖晶石锰酸锂,在锂与锰的原子比从0.95:2到1.1:2范围内,其结构为单一尖晶石相,品格常数和比容量随着锂锰比的增加呈现出先增大后降低的变化规律.在锂锰比为1.0:2和1.02:2附近,晶格常数和比容量分别达到最大.这种变化规律与锂离子在晶格中的位置有关.在锂锰比从1.0:2到1.1:2的范围内,随着锂锰比的增加,尖晶石锰酸锂嵌脱锂反应过程的动力学极化逐渐降低,大电流性能逐渐提高.以尖晶石锰酸锂为正极,MCMB为负极组装了423048型电池,锂锰比从1.0:2到1.1:2,电池循环稳定性随锰酸锂的锂锰比的增大而提高.更多还原

【Abstract】 Lithium manganese oxides with different amount of Li/Mn molar ratio were synthesized by solid state reaction of EMD and Li2CO3. The influence of Li/Mn molar ratio on the structure and electrochemical characteristics of spinel LiMn2O4 is analyzed. The results show that all the synthesized products are single spinel phases with Li/Mn molar ratio ranging from 0.95/2 to 1.1/2. The lattice parameter and the discharge specific capacity increase along with the increase of the Li/Mn molar ratio, and then decrease with increasing amount of Li/Mn molar ratio. This phenomenon may be attributed to the site occupancy of lithium in the lattice. The results also reveal that the kinetic polarization during the intercalation /de-intercalation of lithium ion decrease with increasing Li/Mn molar ratio. The 423048-type battery was assembled with LiMn2O4 as cathode and MCMB as anode . Increasing the Li/Mn ratio leads to an improvement of the cycle performance (Li/Mn=1.0/2 to 1.1/2).更多还原