高温固相法一步合成碳包覆钛酸锂

摘要

以纳米二氧化钛(TiO2)、碳酸锂(Li2CO3)、蔗糖(C12H22O11)为原料,以去离子水作混合溶剂,以氩气(Ar)作为保护气,高温固相合成了碳包钛酸锂(Li4Ti5O12/C)材料.采用XRD、SEM和电化学测试等方法分别对合成材料的结构、形貌和电化学性能进行了表征.结果表明:与传统的高温固相法合成的钛酸锂相比,碳包覆钛酸锂的颗粒明显减小,一次颗粒平均粒度为82 nm;碳包覆钛酸锂放电比容量明显提高,0.1 C、1.0 C、5.0 C倍率下的放电质量比容量分别为171.3、162.3、157.8 mAh/g,循环20周后的容量保持率为100％.%The Li4Ti5O12/C material was synthesized by high temperature solid state with Li2CO3,TiO2 and sucrose (C12H22O11) as raw material,with deionized water as mixed solvent,with argon as protective gas.The crystalline structure,morphology and electrochemical performances of the sample were investigated by X-ray diffraction,scanning electron microscope and charge discharge test.The results show,compared with lithium titanate synthesized by traditional high temperature solid state,the particle size of carbon coating lithium titanate is obviously smaller.The average particle size of the primary particle is only 82 nm.The discharge specific capacity of carbon coating lithium titanate is obviously higher,and the discharge specific capacity are 171.3,162.3,157.8 mAh/g by the charge-discharge rate of 0.1 C,1 C,5 C respectively,and the capacity retention rate is 100％ after 20 cycles.