Operando X-ray photoelectron spectroscopy of solid electrolyte interphase formation and evolution in Li2S-P2S5 solid-state electrolytes
Operando X-ray photoelectron spectroscopy of solid electrolyte interphase formation and evolution in Li2S-P2S5 solid-state electrolytes
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DOI：
10.1038/s41467-018-04762-z
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发表时间：
2018-06-27
影响因子：
16.6
通讯作者：
Teeter, Glenn
中科院分区：
文献类型：
--
作者：
Wood, Kevin N.;Steirer, K. Xerxes;Teeter, Glenn
固态电解质如Li 2S-P2 S5化合物是可以实现Li金属阳极的有前景的材料。然而，许多固态电解质对金属锂不稳定，并且对这些界面在循环过程中的化学演变知之甚少，阻碍了这些材料的合理设计。在这项工作中，operando X射线光电子能谱和实时原位俄歇电子能谱映射的开发，以探测在电化学循环过程中的Li/Li 2S-P2 S5固体电解质界面的形成和演变，并测量与特定的界面成分相关的个人过电位。Li/Li 2S-P2 S5体系的结果表明，电化学驱动Li+到表面导致相分解成Li 2S和Li 3 P。此外，Li 2S-P2 S5中的氧污染最初导致Li 3 PO 4相分离，随后导致Li 2 O形成。这些相的空间非均匀分布，加上它们的离子电导率的差异，对固体电解质界面的整体性质和性能具有重要意义。
Solid-state electrolytes such as Li2S-P2S5 compounds are promising materials that could enable Li metal anodes. However, many solid-state electrolytes are unstable against metallic lithium, and little is known about the chemical evolution of these interfaces during cycling, hindering the rational design of these materials. In this work, operando X-ray photoelectron spectroscopy and real-time in situ Auger electron spectroscopy mapping are developed to probe the formation and evolution of the Li/Li2S-P2S5 solid-electrolyte interphase during electrochemical cycling, and to measure individual overpotentials associated with specific interphase constituents. Results for the Li/Li2S-P2S5 system reveal that electrochemically driving Li+ to the surface leads to phase decomposition into Li2S and Li3P. Additionally, oxygen contamination within the Li2S-P2S5 leads initially to Li3PO4 phase segregation, and subsequently to Li2O formation. The spatially non-uniform distribution of these phases, coupled with differences in their ionic conductivities, have important implications for the overall properties and performance of the solid-electrolyte interphase.