High-rate characteristics of novel anode Li4Ti5O12/polyacene materials for Li-ion secondary batteries
High-rate characteristics of novel anode Li4Ti5O12/polyacene materials for Li-ion secondary batteries
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DOI：
10.1016/j.electacta.2007.12.052
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发表时间：
2008-05
影响因子：
6.6
通讯作者：
Haiying Yu;Xianfa Zhang;A. Jalbout;Xuedong Yan;X. Pan;Haiming Xie;Rongshun Wang
中科院分区：
文献类型：
--
作者：
Haiying Yu;Xianfa Zhang;A. Jalbout;Xuedong Yan;X. Pan;Haiming Xie;Rongshun Wang
近年来，尖晶石型钛酸锂（Li 4 Ti 5 O 12）作为一种上级的储能电池负极材料，因其优异的锂离子嵌入和脱嵌可逆性而备受关注。然而，如果将其用作大型电池中的活性材料，则应改善该材料的高倍率特性。实现这一点的一种有效方法是制备涂覆有碳的电极材料。采用原位碳化法制备了Li 4 Ti 5 O 12/聚并苯（PAS）碳基复合材料。SEM分析表明，复合材料中的Li 4 Ti 5 O 12颗粒比未复合材料中的Li 4 Ti 5 O 12颗粒更圆、更小。PAS均匀地分散在Li 4 Ti 5 O 12颗粒之间，这改善了相应的Li 4 Ti 5 O 12颗粒之间的电接触，从而改善了复合材料的电子导电性。Li 4 Ti 5 O 12/PAS复合材料的电子电导率为10− 1 Scm −1，远高于原始Li 4 Ti 5 O 12的10− 9 Scm − 1。该Li 4 Ti 5 O 12/PAS电极材料实现了高比容量，特别是更好的高倍率性能。样品在3C下的初始比容量为144 mAh/g，循环200次后仍为126.2mAh/g。通过增加电流密度，样品仍然保持优异的循环性能。
In recent years, spinel lithium titanate (Li4Ti5O12) as a superior anode material for energy storage battery has attracted a great deal of attention because of the excellent Li-ion insertion and extraction reversibility. However, the high-rate characteristics of this material should be improved if it is used as an active material in large batteries. One effective way to achieve this is to prepare electrode materials coated with carbon. A Li4Ti5O12/polyacene (PAS) composite were first prepared via an in situ carbonization of phenol–formaldehyde (PF) resin route to form carbon-based composite. The SEM showed that the Li4Ti5O12particles in the composite were more rounded and smaller than the pristine one. The PAS was uniformly dispersed between the Li4Ti5O12particles, which improved the electrical contact between the corresponding Li4Ti5O12particles, and hence the electronic conductivity of composite material. The electronic conductivity of Li4Ti5O12/PAS composite is 10−1Scm−1, which is much higher than 10−9Scm−1of the pristine Li4Ti5O12. High specific capacity, especially better high-rate performance was achieved with this Li4Ti5O12/PAS electrode material. The initial specific capacity of the sample is 144mAh/g at 3C, and it is still 126.2mAh/g after 200 cycles. By increasing the current density, the sample still maintains excellent cycle performance.