期刊
ACS APPLIED MATERIALS & INTERFACES
卷 13, 期 2, 页码 2547-2557出版社
AMER CHEMICAL SOC
DOI: 10.1021/acsami.0c17936
关键词
SnO2; operando XPS; in situ XAS; Li2SnO3; Li8SnO6; SnO; LixSn
资金
- PSI CROSS initiative
Based on experimental observations, redox reactions were identified during the cycling of the SnO2 electrode, including conversion and alloying reactions during lithiation and delithiation processes. The theoretical predictions for the reactions were validated, resolving previous uncertainties about the reaction mechanisms.
We experimentally determine the redox reactions during (de-)lithiation of the SnO2 working electrode cycled in (Li2S)(3)-P2S5 solid electrolyte by combining operando X-ray photoelectron spectroscopy and in situ X-ray absorption spectroscopy. Specifically, we have accurately determined the composition changes in the SnO2 working electrode upon cycling and identified the onset voltage formation of the various phases. Starting from the open-circuit potential, we find that, on lithiation, the Sn M-edge absorption spectra reveal unequivocally the formation of SnOx (x <= 1) and Li2SnO3 already at a potential of 1.6 V vs Lip/Li, while Sn 3d/Sn 4d, O 1s, and Li is core-level spectra show the formation of Sn degrees and Li2 0 along the first potential plateau at 0.8 V vs Li+/Li and of Li8SnO6 at lower potentials. Below 0.6 V vs Li+/Li, an alloying reaction takes place until the end of the lithiation process at 0.05 V vs Li+/Li, as shown by the formation of LixSn. During delithiation, both the conversion and alloying reactions are found to be partially reversible, starting by the re-formation of Sn-0 at 0.3 V vs Li+/Li and followed by the re-formation of Li8SnO6 and SnOx above 0.5 V vs Li+/Li. The conversion and alloying reactions are found to overlap during both lithiation and delithiation. Finally, we validate the theoretical prediction for the SnO2 conversion and alloy (de-)lithiation reactions and clarify the open questions about their reaction mechanism.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据