【作者】 何则强； 熊利芝； 吴显明； 陈上； 黄可龙；

【Author】 HE Ze-qiang~(1,2) XIONG Li-zhi~(1,2) WU Xian-ming~2 CHEN Shang~2 HUANG Ke-long~1 (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)

【机构】 中南大学化学化工学院； 吉首大学化学化工学院；

【摘要】 以 LiMn₂O₄、醋酸锂和钛酸四丁酯为原料,乙醇为溶剂,采用原位复合法制备 LiMn₂O₄/Li₄Ti₅O₁₂复合材料。采用 X 射线衍射分析、红外光谱、扫描电镜和电化学测试等手段对复合材料进行表征。结果表明,在 LiMn₂O₄/Li₄Ti₅O₁₂复合材料中晶态的 LiMn₂O₄表面被无定形结构的 Li₄Ti₅O₁₂包覆,但 Li₄Ti₅O₁₂的存在并没有改变 LiMn₂O₄的晶体结构。由于 Li₄Ti₅O₁₂的包覆,LiMn₂O₄的倍率性能和高温性能都得到显著提高:室温下2.0C 放电时20次循环后 LiMn₂O₄/Li₄Ti₅O₁₂复合材料的可逆容量达到108.4mA·h/g,平均每次循环的容量损失只有 0.053%;而55℃ 1.0C 放电时,经60次循环后 LiMn₂O₄/Li₄Ti₅O₁₂的放电容量为109.9 mA·h/g,平均每次循环的容量损失为0.036%。更多还原

【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.更多还原