Impact of dual-layer solid-electrolyte interphase inhomogeneities on early-stage defect formation in Si electrodes

Chunguang Chen (1, 2) , Tao Zhou (3, 4) , Dmitri L Danilov (1, 2) , Lu Gao (2) , Svenja Benning (1, 5) , Nino Schön (1, 5) , S. Tardif (6) , Hugh Simons (7) , Florian Hausen (1, 5) , Tobias Schülli (3) , R.-A. Eichel (1, 5) , Peter H L Notten (1, 2, 8)

1 IEK-9 - Institute of Energy and Climate Research - Fundamental Electrochemistry
2 TU/e - Eindhoven University of Technology [Eindhoven]
3 ESRF - European Synchrotron Radiation Facility
4 ANL - Argonne National Laboratory [Lemont]
5 RWTH - Rheinisch-Westfälische Technische Hochschule Aachen University
6 NRS - Nanostructures et Rayonnement Synchrotron
7 DTU - Danmarks Tekniske Universitet = Technical University of Denmark
8 UTS - University of Technology Sydney

While intensive efforts have been devoted to studying the nature of the solid-electrolyte interphase (SEI), little attention has been paid to understanding its role in the mechanical failures of electrodes. Here we unveil the impact of SEI inhomogeneities on early-stage defect formation in Si electrodes. Buried under the SEI, these early-stage defects are inaccessible by most surface-probing techniques. With operando full field diffraction X-ray microscopy, we observe the formation of these defects in real time and connect their origin to a heterogeneous degree of lithiation. This heterogeneous lithiation is further correlated to inhomo-geneities in topography and lithium-ion mobility in both the inner-and outer-SEI, thanks to a combination of operando atomic force microscopy, electrochemical strain microscopy and sputter-etched X-ray photoelectron spectroscopy. Our multi-modal study bridges observations across the multi-level interfaces (Si/Li x Si/inner-SEI/outer-SEI), thus offering novel insights into the impact of SEI homogeneities on the structural stability of Si-based lithium-ion batteries.

Domains: Chemical Sciences; Material chemistry; Physics [physics]; Condensed Matter [cond-mat]; Materials Science [cond-mat.mtrl-sci]

Chunguang Chen, Tao Zhou, Dmitri L Danilov, Lu Gao, Svenja Benning, et al.. Impact of dual-layer solid-electrolyte interphase inhomogeneities on early-stage defect formation in Si electrodes. Nature Communications, 2020, 11, pp.3283. ⟨10.1038/s41467-020-17104-9⟩. ⟨cea-02888302⟩