锂离子电池用LixMn2O4的高温性能研究

采用固相反应法以工业级原料合成了不同Li/Mn比的 3种锂锰尖晶石氧化物 ,并以循环伏安实验及 5 5℃下的恒流充放电实验考察了Li/Mn比对材料结构和性能的影响。高Li/Mn比的样品具有较好的高温循环性能 ,原因是①Mn3 +的含量降低 ,锰溶解及Jahn -Teller效应受到抑制 ,②充放电过程中结构变化平缓 ,保持了材料结构的稳定性 ;③可逆工作的Li+减少使得充放电过程中晶格体积变化减小 ,同时也提高了材料的抗过充电能力

High temperature performance of LixMn2O4 as cathode material for lithium- ion batteries

Three spinel Lix Mn2O4 oxides with different Li/Mn ratio were synthesized by solid state reaction from industrial grade precursors. Galvanostatic charge/discharge tests at 55℃ and cyclic voltammetry experiments were conducted to evaluate the effect of Li/Mn ratio on the material structure and the electrochemical performance of the oxides. Sample with high Li/Mn ratio exhibited best cycling performance at elevated temperature, owing to: 1 suppression of manganese dissolution and Jahn Teller effect due to the decreased Mn3+ content;2 structural stability due to less abrupt structural evolution during homogeneous intercalation/deintercalation process;3 reduced cell volume change and increased resistance against overcharge during cycling as a result of the presence of residual lithium in fully charged state.