高温固相反应中锂锰氧的结构及性能

Structure and electrochemical performance of spinel Li_xMn_2O_4 synthesized under different temperature

用高温固相法合成了不同n(Li)/n(Mn)含量的尖晶石型锂锰氧化合物,并对其进行XRD分析及充放电测试。实验表明:当锂、锰物质的量比为0.525,在700℃下煅烧36h时,可合成纯的尖晶石相,其首次放电容量达119.7mAh/g。尖晶石型锂锰氧的热稳定性与工艺过程、反应温度有关;非化学计量LixMn2O4材料中的Mn平均氧化价态随其中Li含量的变化而变化;锂锰氧中锂含量对充电过程的电极电势有较大影响。

Different n(Li)/n(Mn) spinel LixMn2O4 was synthesized by solid phase reaction at high temperature.Structure and electrochemical performance of the material were investigated by Xray diffraction and chargedischarge tests. The experimental results showed that pure spinel structure was formed,when the material was calcined at 700?℃ for 36?h with the mole ratio of 0.525 of Li to Mn. The first discharge capacity of the material was up to 119.7?mAh/g.The thermostability of spinel LixMn2O4 was related to process engineering and reaction temperature.The average chemical valence of Mn in LixMn2O4 varied with the content of Li.The content of Li in LixMn2O4 had large influence on electrode potential during discharge.