@article{32443,
  author = {Zachary W Lebens-Higgins and Hyeseung Chung and Mateusz J Zuba and Jatinkumar Rana and Yixuan Li and Nicholas V Faenza and Nathalie Pereira and Bryan D McCloskey and Fanny Rodolakis and Wanli Yang and M. M Stanley Whittingham and Glenn G Amatucci and Ying Shirley Meng and Tien-Lin Lee and Louis F. J Piper},
  title = {How Bulk Sensitive is Hard X-ray Photoelectron Spectroscopy: Accounting for the Cathode{\textendash}Electrolyte Interface when Addressing Oxygen Redox},
  abstract = {<p><span>Sensitivity to the {\textquotedblleft}bulk{\textquotedblright} oxygen core orbital makes hard X-ray photoelectron spectroscopy (HAXPES) an appealing technique for studying oxygen redox candidates. Various studies have reported an additional O 1s peak (530{\textendash}531 eV) at high voltages, which has been considered a direct signature of the bulk oxygen redox process. Here, we find the emergence of a 530.4 eV O 1s HAXPES peak for three model cathodes{\textemdash}Li</span><span>2</span><span>MnO</span><span>3</span><span>, Li-rich NMC, and NMC 442{\textemdash}that shows no clear link to oxygen redox. Instead, the 530.4 eV peak for these three systems is attributed to transition metal reduction and electrolyte decomposition in the near-surface region. Claims of oxygen redox relying on photoelectron spectroscopy must explicitly account for the surface sensitivity of this technique and the extent of the cathode degradation layer.</span></p>},
  year = {2020},
  booktitle = {The Journal of Physical Chemistry Letters},
  journal = {The Journal of Physical Chemistry Letters},
  series = {The Journal of Physical Chemistry Letters},
  volume = {11},
  pages = {2106 - 2112},
  month = {02/2020},
  issn = {1948-7185},
  doi = {10.1021/acs.jpclett.0c00229},
  language = {eng},
}