Solid Electrolyte Interphase (SEI) at TiO2 Electrodes in Li-Ion Batteries: Defining Apparent and Effective SEI Based on Evidence from X-ray Photoemission Spectroscopy and Scanning Electrochemical Microscopy

2026-04-17T20:42:01Zhttps://riubu.ubu.es/oai/request

oai:riubu.ubu.es:10259/113772026-02-18T01:05:43Zcom_10259_5822com_10259_5086com_10259_2604col_10259_5823

Solid Electrolyte Interphase (SEI) at TiO2 Electrodes in Li-Ion Batteries: Defining Apparent and Effective SEI Based on Evidence from X-ray Photoemission Spectroscopy and Scanning Electrochemical Microscopy Ventosa Arbaizar, Edgar Madej, Edyta Zampardi, Giorgia Mei, Bastian Weide, Philipp Antoni, Hendrik La Mantia, Fabio Muhler, Martin Schuhmann, Wolfgang Li-on batteries Solid electrolyte interphase X-ray photoemission Scanning electrochemical microscopy Titanium dioxide The high (de)lithiation potential of TiO2 (ca. 1.7 V vs Li/Li+ in 1 M Li+) decreases the voltage and, thus, the energy density of a corresponding Li-ion battery. On the other hand, it offers several advantages such as the (de)lithiation potential far from lithium deposition or absence of a solid electrolyte interphase (SEI). The latter is currently under controversial debate as several studies reported the presence of a SEI when operating TiO2 electrodes at potentials above 1.0 V vs Li/Li+. We investigate the formation of a SEI at anatase TiO2 electrodes by means of X-ray photoemission spectroscopy (XPS) and scanning electrochemical microscopy (SECM). The investigations were performed in different potential ranges, namely, during storage (without external polarization), between 3.0–2.0 V and 3.0–1.0 V vs Li/Li+, respectively. No SEI is formed when a completely dried and residues-free TiO2 electrode is cycled between 3.0 and 2.0 V vs Li/Li+. A SEI is detected by XPS in the case of samples stored for 6 weeks or cycled between 3.0 and 1.0 V vs Li/Li+. With use of SECM, it is verified that this SEI does not possess the electrically insulating character as expected for a “classic” SEI. Therefore, we propose the term apparent SEI for TiO2 electrodes to differentiate it from the protecting and effective SEI formed at graphite electrodes. 2026-02-17 2026-02-17 2016-12 info:eu-repo/semantics/article 1944-8244 https://hdl.handle.net/10259/11377 10.1021/acsami.6b13306 1944-8252 eng ACS Applied Materials & Interfaces. 2016, V. 9, n. 3, p. 3123-3130 https://doi.org/10.1021/acsami.6b13306 info:eu-repo/semantics/openAccess American Chemical Society