Li4Ti5O12 nanosheets as high-rate and long-life anode materials for sodium-ion batteries
Li4Ti5O12 nanosheets as high-rate and long-life anode materials for sodium-ion batteries
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Li4Ti5O12纳米片作为钠离子电池高倍率、长寿命负极材料
DOI：
10.1039/c5ta07403g
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发表时间：
2015-01-01
影响因子：
11.9
通讯作者：
Lei, Ming
中科院分区：
文献类型：
--
作者：
Yang, Lin Yu;Li, Hui Zhong;Lei, Ming
根据最近的报道，多相设计可以提供一种新的方法来提高锂离子电池（lib）的L4T5O12-TiO2阳极的性能。但在钠离子电池（sib）中，很少有人关注TiO2相是否具有与锂离子电池相似的效应。本文通过简单的水热反应，成功地大规模制备了均匀原始的Li4Ti5O12 （LTO）和Li4Ti5O12-金红石型TiO2 （LTO- rt）纳米片。首次比较了它们作为sib阳极的电化学性能。结果表明，LTO-TiO2复合材料中TiO2相的存在对sib阳极的容量有积极影响，但对循环性有消极影响，这与之前报道的LTO-TiO2复合材料中TiO2相作为lib阳极的影响有很大不同。此外，通过我们的合成方法制备的LTO纳米片在1C下提供高达145 mA h g（-1）的可逆容量，并且在400次循环后保持91%的容量保留率。据我们所知，这是迄今为止使用LTO作为阳极材料的sib的最长循环寿命。基于扫描速率相关的循环伏安测试，首次提出了在原始LTO电极中存储na离子的赝电容电荷存储机制，这有助于LTO电极在sib中具有优异的速率容量和高循环稳定性。
According to recent reports, a multiphase design can provide a new method to improve the performance of L4T5O12-TiO2 anodes for lithium-ion batteries (LIBs). But in the case of sodium-ion batteries (SIBs), little attention is paid to the investigation of whether TiO2 phases have similar effects as they have in LIBs. In this paper, uniform pristine Li4Ti5O12 (LTO) and Li4Ti5O12-rutile TiO2 (LTO-RT) nanosheets were successfully fabricated on a large scale via a simple hydrothermal reaction. Their electrochemical performance as anodes for SIBs was carefully compared for the first time. The results show that the existence of TiO2 phases in LTO-TiO2 composites has a positive effect on the capacity but a negative effect on the cyclability as anodes for SIBs, which is very different from the previously reported effects of TiO2 phases in LTO-TiO2 composites as anodes for LIBs. Moreover, LTO nanosheets fabricated by our synthesis method deliver a reversible capacity up to 145 mA h g(-1) at 1C and keep 91% capacity retention after 400 cycles. As far as we know, this is the longest cycle life to date for SIBs using LTO as anode materials. Based on a scan rate-dependent cyclic voltammetry test, a pseudocapacitive charge storage mechanism has been firstly proposed for Na-ion storage in a pristine LTO electrode, which contributes to the excellent rate capacity and such high cycling stability of LTO electrodes for SIBs.