不同形貌LiMn2O4的电化学及Li+扩散性能

合成了球形和立方体形貌的MnCO3前驱体,再用熔融浸渍和程序升温法煅烧,得到两种LiMn2O4正极材料.XRD和SEM分析表明:两种LiMn2O4均为纯净立方尖晶石型,颗粒形貌保持完好.球形材料的性能优于立方体形材料,在3.50～4.30 V充放电,0.1C首次放电比容量为133.4 mAh/g,5.0C平均放电比容量...

Electrochemical and Li + diffusion performance of LiMn2O4 with different morphology

MnCO3 precursors with spherical and cubic morphology were synthesized and subsequently transformed to two kinds of LiMn2O4 cathode material through meltimpregnation and temperature programmed process.XRD and SEM analyses showed that both of the two kinds of LiMn2O4 had pure phase of cubic spinel structure,the morphology was well retained during the calcination process.The spherical material had better electrochemical performance than the cubic one,which delivered an initial specific discharge capacity of 133.4 mAh/g at 0.1 C and remained average specific discharge capacity of 104.3 mAh/g at 5.0 C when charged-discharged in 3.50～4.30 V.The diffusion coefficients of Li+(DLi)varied from 10-10～10-12 cm2/s in 3.80～4.30 V were tested by potentiostatic intermittent titration technique(PITT),appeared two minimum values at around 4.00 V and 4.15 V.