Depth profiling the solid electrolyte interpahase on lithium titanate (Li4Ti5O12) using synchrotron-based photoelectron spectroscopy
2015 (English)In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 294, 173-179 p.Article in journal (Refereed) Published
The presence of a surface layer on lithium titanate (Li4Ti6O12, LTO) anodes, which has been a topic of debate in scientific literature, is here investigated with tunable high surface sensitive synchrotron-based photoelectron spectroscopy (PES) to obtain a reliable depth profile of the interphase. Li vertical bar vertical bar LTO cells with electrolytes consisting of 1 M lithium hexafluorophosphate dissolved in ethylene carbonate:diethyl carbonate (LiPF6 in EC:DEC) were cycled in two different voltage windows of 1.0-2.0 V and 1.4-2.0 V. LTO electrodes were characterized after 5 and 100 cycles. Also the pristine electrode as such, and an electrode soaked in the electrolyte were analyzed by varying the photon energies enabling depth profiling of the outermost surface layer. The main components of the surface layer were found to be ethers, P-O containing compounds, and lithium fluoride.
Place, publisher, year, edition, pages
2015. Vol. 294, 173-179 p.
Li-ion batteries, LTO, PES, XPS, Surface layer, SEI
Energy Engineering Chemical Sciences
IdentifiersURN: urn:nbn:se:uu:diva-261214DOI: 10.1016/j.jpowsour.2015.06.038ISI: 000358968400022OAI: oai:DiVA.org:uu-261214DiVA: diva2:852181
FunderSwedish Energy Agency