摘要
采用溶胶-凝胶法合成了纯相、结晶度高、粒径为40~100 nm的钛酸锂粉体,使用X射线衍射（XRD）、扫描电镜（SEM）和投射电子显微镜（TEM）技术对样品进行了物相分析和形貌表征。优化条件为：反应物摩尔比Li/Ti=4.2/5~4.4/5、煅烧温度700~750℃、煅烧时间9~12 h。对钛酸锂进行石墨烯掺杂改性的方法是,将自制的钛酸锂粉体、氧化石墨粉体和水合肼按比例混合在一起,经100℃油浴加热24 h即可得到的石墨烯掺杂改性钛酸锂的复合材料,此材料仍为尖晶石型结构,结晶度高、分散性好且无杂质生成。经测试,Li4Ti5O12样品首次放电比容量达到163 mAh/g,改性后Li4Ti5O12复合材料首次放电比容量提高,达到175 mAg/h。
The phase pure and well-crystallized Li4Ti5O12 powder with 40-100 nm particle size was synthesized by sol-gel method using tetrabutyl titanate,lithium hydroxide monohydrate（LiOH·H2O） as raw materials.XRD,SEM,and TEM techniques were used to characterize the phase and morphology.The optimal synthetic conditions for preparation of Li4Ti5O12 were as follows： the molar ratio of Li to Ti is 4.2/5-4.4/5,the calcination temperature is 700-750 ℃,and the calcination time is 9-12 h.The modification process was that the synthesized Li4Ti5O12 powder,graphite oxide powder and hydrazine hydrate were mixed in proportion and were heated in an oil bath at 100 ℃ for 24 h.The composites after doping modification with graphene were still spinel type with high crystallization and better dispersity.The composites possessed no impurities as was observed from the XRD.The initial discharge specific capacity of Li4Ti5O12 was close to 163 mAh/g,while the initial discharge specific capacity of ones modified was 175 mAh/g.
出处
《电源技术》
CAS
CSCD
北大核心
2013年第1期28-31,共4页
Chinese Journal of Power Sources
