【摘要】 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平均放电比容量达104.3 mAh/g。用恒电位间歇滴定技术(PITT)测得Li+扩散系数(DLi)在3.80～4.30 V为10-10～10-12cm2/s,在4.00 V和4.15 V左右出现两个极小值。更多还原

【Abstract】 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.更多还原