In situ hard X-ray photoelectron spectroscopy on the origin of irreversibility in electrochromic LixWO3 thin films
In situ hard X-ray photoelectron spectroscopy on the origin of irreversibility in electrochromic LixWO3 thin films
复制标题
DOI：
10.1016/j.apsusc.2021.150898
复制
发表时间：
2021-12
影响因子：
6.7
通讯作者：
M. Takayanagi;T. Tsuchiya;S. Ueda;T. Higuchi;K. Terabe
中科院分区：
文献类型：
--
作者：
M. Takayanagi;T. Tsuchiya;S. Ueda;T. Higuchi;K. Terabe
已知电致变色WO_3(LixWO_3)中Li+的插入有三种成分：(I)可逆的Li+，(Ii)不可逆的Li2WO_4形成和(Iii)不可逆的Li+俘获。为了研制基于LixWO_3的电致变色器件，进行了原位硬X射线光电子能谱(HAXPES)、原位拉曼光谱和电化学测试。原位HAXPES可以定量区分(I)可逆Li+和(III)不可逆Li+陷阱作为W离子氧化状态的变化，而电化学测量可以评估(I)可逆Li+和(II)不可逆Li_2WO_4生成和(III)不可逆Li+陷阱的总和。此外，原位拉曼光谱还检测到了Li+掺杂对结晶度的提高，并具有较高的灵敏度。原位HAXPES和电化学测量的结合使得(I)、(II)和(III)的分离和定量评价成为可能。阐明了(I)可逆Li+、(Ii)不可逆Li_2WO_4形成和(Iii)不可逆Li+捕获对整个插入Li+的插入Li+转化率。(即分别为41.4%、50.9%和7.7%)。
Three kinds of components are known in the insertion of Li+into electrochromic WO3(LixWO3): (i) reversible Li+, (ii) irreversible Li2WO4formation and (iii) irreversible Li+trapping. To develop LixWO3-based electrochromic devices, in situ hard X-ray photoelectron spectroscopy (HAXPES), in situ Raman spectroscopy and electrochemical measurements were performed. In situ HAXPES can quantitatively distinguish (i) reversible Li+and (iii) irreversible Li+trapping as the variation in the oxidation state of the W ion whereas the electrochemical measurements can evaluate (i) reversible Li+and the sum of (ii) irreversible Li2WO4formation and (iii) irreversible Li+trapping. Furthermore, in situ Raman spectroscopy detected the enhancement of crystallinity due to Li+insertion with high sensitivity. The combination of the in situ HAXPES and the electrochemical measurements enables the separation and quantitative evaluation of (i), (ii) and (iii). The inserted Li+conversion ratios of (i) reversible Li+, (ii) irreversible Li2WO4formation and (iii) irreversible Li+trapping to the entire inserted Li+were clarified. (i.e., 41.4 %, 50.9 %, and 7.7 %, respectively).