【摘要】 采用溶胶凝胶法合成一种新型的Li₅Cr₉Ti₄O₂₄钛酸盐材料,用X射线粉末衍射（XRD）、扫描电子显微镜（SEM）、循环伏安（CV）、充放电测试和阻抗测试等方法研究了样品的结构和电化学性能。结果表明,Li₅Cr₉Ti₄O₂₄粒径大小约为100²00 nm,具有同LiCrTiO₄相似的晶格结构;循环伏安曲线表在1.227 V/1.772 V和1.334 V/1.761 V处出现氧化还原峰;在不同倍率下充放电时,Li₅Cr₉Ti₄O₂₄有较好的放电比容量和倍率性能,大倍率充放电曲线表明Li₅Cr₉Ti₄O₂₄材料具有很高的循环稳定性;阻抗图表明循环后的Li₅Cr₉Ti₄O₂₄材料生成SEI膜。更多还原

【Abstract】 A new titanate material Li₅Cr₉Ti₄O₂₄ was prepared by a simple sol-gel method. The structure and electrochemical performance of the materials were investigated by X-ray diffractometry（ XRD）,scanning electron microscope（ SEM）,cyclic voltammetry（ CV）,charge-discharge tests and electro chemical impedance spectroscopy（ EIS）. The results show that Li₅Cr₉Ti₄O₂₄ material has similar lattice structure with LiCrTiO₄ and the particle size of Li₅Cr₉Ti₄O₂₄ material is about 100—200 nm.Cyclic voltammetry curves indicate that there are reversible redox peaks at 1. 227 V/1. 772 V and 1. 334 V/1. 761 V. Charge-discharge tests exhibit that the Li₅Cr₉Ti₄O₂₄ material has good specific discharge capacity and rate capability at different rates. Charge-discharge curves at high rates show that Li₅Cr₉Ti₄O₂₄ material has high cycling stability. EIS patterns show that the solid electrolyte interphase（ SEI） film on the surface of Li₅Cr₉Ti₄O₂₄ material can be found after cycling.更多还原