尖晶石锰酸锂粒度和离子改性对其循环性能的影响

Influence of Particle Sizes and Modification on Cycle Performance of Spinel LiMn_2O_4

以电解二氧化锰(EMD)和碳酸锂为原料采用固相法合成了尖晶石结构锰酸锂,锰酸锂和原材料电解二氧化锰的颗粒粒度和形貌具有相似性。在试验范围内,降低锰酸锂中超细颗粒,其循环稳定性得到了明显的改善;过量的锂对锰酸锂改性,随着锂加入量的增大,50℃下改性锰酸锂材料循环稳定性呈逐渐上升趋势,同时比容量有所下降。通过粒度调整、离子改性,合成了比容量为92.2mAh.g-1的改性锰酸锂材料,50℃下循环170次容量保持88%,显示出较好的循环稳定性。

Spinel LiMn204 was synthesized by solidstate reaction with starting materials of MnO2 （EMD） and Li2CO3, and the as-prepared the LiMn2O4 inherited the particle size and morphology of MnO2. The cycle performance of LiMn2O4 was greatly improved by reducing the amount of ultrafine particles in experimental region; LiMn2O4 was modified with excess lithi-um, the cycle stability of the modified LiMn2O4 at 50 ℃ was improved sequentially, whereas the specific capacity decreased with increasing the content of lithium. The modified LiMn2O4 was synthesized by adjusting particle size and secondary modifying, and it had specific capacity of 92.2 mAh· g^-1 and very good capacity retention of 88% after 170 cycles at 50 ℃.