以硝酸锂、钛酸正丁酯和糠醇为反应物,采用糠醇聚合凝胶法制备了纳米LiaT5O12粉体.利用XRD、SEM和BET比表面测试对产物进行了表征,并研究了纳米Li4T5O12粉体作为锂离子电池负极材料的电化学性能.在700℃或更高温度烧结时产物为纯相的尖晶石型.通过柠檬酸、聚乙烯吡咯烷酮、十六烷基三甲基溴化铵(CTAB)表面活性剂的加入能够减少产物颗粒的团聚程度,增大粉体的比表面积,提高其电化学性能.加入0.5gCTAB、700℃烧结12h的Li4T5O12粉体展示出最高的比容量和最佳的循环性能,10C下充电比容量高达156.7mAh/g.
Nanosized Li4Ti5O12 powders are synthesized by a polymerization-based method using ti- tanium butoxide and lithium nitrate as precursors and furfuryl alcohol as a polymerizable solvent. The prepared samples are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Braunauer-Emmett-Teller (BET) analysis. The electrochemical performances of these Li4Ti5O12 powders are also studied. The effect of different surfactants including citric acid, polyvinylpyrrolidone, and cetyltrimethyl ammonium bromide on the structure and properties is also investigated. It is found that pure spinel phase of Li4Ti5O12 is obtained at an annealing temperature of 700 ℃ or higher. The use of surfactants can improve the powder morphology of nanosized particles with less agglomeration. With suitable annealing temperature and the addition of surfaetant, Li4Ti5O12 powders with high BET surface area and favorable electrochemical performance can be obtained.