(1. 中南大學(xué) 化學(xué)化工學(xué)院，長沙 410083；
2. 吉首大學(xué) 化學(xué)化工學(xué)院，吉首 416000)
摘 要: 以LiMn2O4、醋酸鋰和鈦酸四丁酯為原料，乙醇為溶劑，采用原位復(fù)合法制備LiMn2O4/Li4Ti5O12復(fù)合材料。采用X射線衍射分析、紅外光譜、掃描電鏡和電化學(xué)測試等手段對復(fù)合材料進(jìn)行表征。結(jié)果表明，在LiMn2O4/Li4Ti5O12復(fù)合材料中晶態(tài)的LiMn2O4表面被無定形結(jié)構(gòu)的Li4Ti5O12包覆，但Li4Ti5O12的存在并沒有改變LiMn2O4的晶體結(jié)構(gòu)。由于Li4Ti5O12的包覆，LiMn2O4的倍率性能和高溫性能都得到顯著提高：室溫下2.0C放電時20次循環(huán)后LiMn2O4/Li4Ti5O12復(fù)合材料的可逆容量達(dá)到108.4mA∙h/g，平均每次循環(huán)的容量損失只有0.053%；而55 ℃ 1.0C放電時，經(jīng)60次循環(huán)后LiMn2O4/Li4Ti5O12的放電容量為109.9 mA∙h/g，平均每次循環(huán)的容量損失為0.036%。
關(guān)鍵字: 鈦酸鋰；錳酸鋰；原位復(fù)合法；鋰離子電池
LiMn2O4/Li4Ti5O12 composite
（1. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;
2. College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, China）
Abstract:LiMn2O4/Li4Ti5O12 composite was synthesized by in-situ composite technique using LiMn2O4, lithium acetate, tetrabutyl titanate as starting materials and was characterized by various electrochemical methods in combination with X-ray diffractometry (XRD), infrared (IR) spectroscopy and scanning electron microscopy (SEM). The results show that the amorphous Li4Ti5O12 is coated on the surface of crystalline LiMn2O4 to form the LiMn2O4/Li4Ti5O12 composite. The structure of LiMn2O4 does not change due to introduction of Li4Ti5O12. Coated with Li4Ti5O12, the rate capability and high temperature cyclability of LiMn2O4 are improved greatly. At room temperature, the discharge capacity of LiMn2O4/Li4Ti5O12 composite is more than 108.4 mA∙h/g and the capacity loss per cycle is only 0.053% after cycling 20 times at 2.0C. While at 55 ℃, the discharge capacity of LiMn2O4/Li4Ti5O12 composite is more than 109.9 mA∙h/g and the capacity loss per cycle is only 0.036% after cycling 60 times at 1.0C.
Key words: Li4Ti5O12; LiMn2O4; in-situ composite technique; lithium ion batteries
