以偏钛酸锂(Li2TiO3)和二氧化钛(TiO2)为原料,采用固相法合成钛酸锂(Li4Ti5O12),通过XRD、SEM和电化学测试等方法对合成的钛酸锂材料的结构、形貌和电化学性能进行表征,同时研究一次颗粒长大规律和反应机理。结果表明:Li2TiO3是传统固...以偏钛酸锂(Li2TiO3)和二氧化钛(TiO2)为原料,采用固相法合成钛酸锂(Li4Ti5O12),通过XRD、SEM和电化学测试等方法对合成的钛酸锂材料的结构、形貌和电化学性能进行表征,同时研究一次颗粒长大规律和反应机理。结果表明:Li2TiO3是传统固相法合成Li4Ti5O12的中间产物,用Li2TiO3为原料在720、750℃保温10 h可合成纯的Li4Ti5O12,制备的一次颗粒粒径分别为270、278 nm,较用Li2CO3和TiO2为原料合成纯相的温度更低,一次颗粒粒径更小。反应期间,一次颗粒粒径随着反应分数的增大呈快速增长势头;反应结束后,一次颗粒粒径增长缓慢。750℃合成的Li4Ti5O12在充放电倍率为0.1C、1C、5C、9C时,比容量分别为170、164、149、126 m A·h/g,在0.1C时循环200次容量保持率大于97%,显示制备的Li4Ti5O12具有良好的电化学性能。展开更多
Conventional cathode material （LiCoO2） was modified by coating with a thin layer of La2O3/Li2O/TiO2 for improving its performance for lithium ion battery. The morphology and structure of the modified cathode materia...Conventional cathode material （LiCoO2） was modified by coating with a thin layer of La2O3/Li2O/TiO2 for improving its performance for lithium ion battery. The morphology and structure of the modified cathode material was characterized by SEM, XRD, and Auger electron spectroscopy. The performance of the cells with the modified cathode material was examined, including the cycling stability, the diffusion coefficient under different voltages, and the C-rate discharge. The results showed that the cell composed of the coated cathode material discharged at a large current density, and possesses a stable cycle performance in the range from 3.0 to 4.4 V. It was explained that the rate of Li ion diffusion increased in the cell while using La2O3/Li2O/TiO2-coated LiCoO2 as the cathode and the coating layer may act as a faster ion conductor （La2O3/Li2O/TiO2）.展开更多
基金Project(2008BAB35B04) supported by the National Key Technologies R&D Program of ChinaProject(2010QZZD003) supported by Central South University Advanced Research Program,China
文摘以偏钛酸锂(Li2TiO3)和二氧化钛(TiO2)为原料,采用固相法合成钛酸锂(Li4Ti5O12),通过XRD、SEM和电化学测试等方法对合成的钛酸锂材料的结构、形貌和电化学性能进行表征,同时研究一次颗粒长大规律和反应机理。结果表明:Li2TiO3是传统固相法合成Li4Ti5O12的中间产物,用Li2TiO3为原料在720、750℃保温10 h可合成纯的Li4Ti5O12,制备的一次颗粒粒径分别为270、278 nm,较用Li2CO3和TiO2为原料合成纯相的温度更低,一次颗粒粒径更小。反应期间,一次颗粒粒径随着反应分数的增大呈快速增长势头;反应结束后,一次颗粒粒径增长缓慢。750℃合成的Li4Ti5O12在充放电倍率为0.1C、1C、5C、9C时,比容量分别为170、164、149、126 m A·h/g,在0.1C时循环200次容量保持率大于97%,显示制备的Li4Ti5O12具有良好的电化学性能。
基金Key Program Project of Natural Science Foundation of Guangdong Province (06105562)
文摘Conventional cathode material （LiCoO2） was modified by coating with a thin layer of La2O3/Li2O/TiO2 for improving its performance for lithium ion battery. The morphology and structure of the modified cathode material was characterized by SEM, XRD, and Auger electron spectroscopy. The performance of the cells with the modified cathode material was examined, including the cycling stability, the diffusion coefficient under different voltages, and the C-rate discharge. The results showed that the cell composed of the coated cathode material discharged at a large current density, and possesses a stable cycle performance in the range from 3.0 to 4.4 V. It was explained that the rate of Li ion diffusion increased in the cell while using La2O3/Li2O/TiO2-coated LiCoO2 as the cathode and the coating layer may act as a faster ion conductor （La2O3/Li2O/TiO2）.
