@article{bibcite_36778,
  author = {Andrew Dopilka and Jonathan M Larson and Robert Kostecki},
  title = {<i>Operando</i> Infrared Nanospectroscopy of the Silicon/Electrolyte Interface during Initial Stages of Solid-Electrolyte-Interphase Layer Formation},
  abstract = {<p>The solid electrolyte interphase (SEI) is a critical component in Li-ion batteries; however, its nanoscale structure and composition and unstable nature make it difficult to characterize and ascertain primary functional mechanisms. We use <em>operando</em> nanoscale Fourier transform infrared spectroscopy (nano-FTIR) with a broadband synchrotron IR source to study the SEI formation on a thin-film Si electrode at nanometer-scale spatial resolution as a function of time and voltage. By probing the Si/carbonate electrolyte interface through a 25 nm-thick amorphous Si window/electrode, we detect molecular vibrational modes within a 10s of nanometers region adjacent to the Si surface and observe that PF<sub>6</sub><sup>{\textendash}</sup> anions react to form LiF at 0.5 V. Spatially resolved nano-FTIR spectra showcase subtle nanoscale heterogeneities in the initial solid/liquid interface and the resulting deposited LiF. With its nanoscale resolution and high chemical specificity, <em>operando</em> nano-FTIR provides unique insights into the dynamics and heterogeneous formation of SEIs and opens opportunities for connecting nanoscale interfacial properties to bulk performance metrics.</p>},
  year = {2025},
  booktitle = {ACS Energy Letters},
  journal = {ACS Energy Letters},
  series = {ACS Energy Letters},
  volume = {10},
  pages = {410-419},
  month = {10/01/2025},
  institution = {American Chemical Society (ACS)},
  publisher = {American Chemical Society (ACS)},
  issn = {2380-8195, 2380-8195},
  url = {https://doi.org/10.1021/acsenergylett.4c03255},
  doi = {10.1021/acsenergylett.4c03255},
}