Reversible lithium insertion into Na2Ti6O13 structure
Reversible lithium insertion into Na2Ti6O13 structure
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DOI：
10.1016/j.elecom.2006.02.017
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发表时间：
2006-04-01
影响因子：
5.4
通讯作者：
Jamnik, J
中科院分区：
文献类型：
--
作者：
Dominko, R;Baudrin, E;Jamnik, J
用部分洗涤的（Na，H）-Ti-O纳米管制备了纯净的Na2Ti6O13相，并将其用作锂离子的插入材料。结果表明，该结构每1 mol Na2Ti6O13可容纳3 mol锂。每一个钛原子容纳0.5 mol锂对应于Ti4+部分还原为Ti3+，并且比钛在八面体氧环境（如Li4Ti5O12）中通常遇到的低几百毫伏。锂插入到这一阶段的评估使用特别的原位x射线。锂插入到Na2Ti6O13相中包括三个区域，对应于两种固溶体，并在1.5 V和1.0 V之间的电位范围内发生双相转变。这个过程是可逆的，因此在再氧化后结构被完全保存。在循环过程中观察到的容量衰减可以用寄生反应来解释，寄生反应归因于暴露的裸表面对电解质降解的催化作用。(c) 2006 Elsevier B.V.版权所有
Pure Na2Ti6O13 phase was successfully prepared from partially washed (Na,H)-Ti-O nanotubes and used as an insertion material for lithium ions. Results show that the structure can accommodate upto 3 mol of lithium per I mol of Na2Ti6O13. Accommodation of 0.5 mol of lithium per one titanium atom corresponds to the partial reduction of Ti4+ to Ti3+ and occurs several 100s of millivolts lower than typically encountered for titanium in an octahedral oxygen environment such as Li4Ti5O12. Lithium insertion into this phase was evaluated using especially in situ X-ray. Lithium insertion into Na2Ti6O13 phase includes three domains corresponding to two solid-solutions and a biphasic transition in the potential range between 1.5 V and 1.0 V vs. lithium. The process is very reversible so that after reoxidation the structure is completely preserved. Capacity fading observed during the cycling is explained by parasitic reactions attributed to a catalytic effect of the exposed bare surface on the electrolyte degradation. (c) 2006 Elsevier B.V. All rights reserved.