X-ray photoelectron spectroscopic investigation of atomic-layer-deposited spinel Li4Ti5O12: Calcination under reducing atmosphere

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Alireza M. Kia - , Fraunhofer Institute for Photonic Microsystems, Freiberg University of Mining and Technology (Author)
  • Jan Speulmanns - , Fraunhofer Institute for Photonic Microsystems (Author)
  • Jennifer Emara - , Fraunhofer Institute for Photonic Microsystems (Author)
  • Pavel Potapov - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Axel Lubk - , CEOS- Endowed Chair of Electron Optics (with IFW), Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Nora Haufe - , Fraunhofer Institute for Photonic Microsystems (Author)

Abstract

Across all material candidates used as anodes in lithium-ion batteries, lithium titanate (Li4Ti5O12) (LTO) is an excellent replacement for conventional electrode materials, such as graphite or silicon. Compares to commercial graphite anodes, LTO offers a higher charging rate and safer operation, and compares to silicon, it undergoes almost no volume expansion during intercalation of lithium ions into the crystal lattice, so-called zero-strain material. However, the LTO performance still suffers from low conductivity due to the oxidation of titanium (Ti) in spinel-LTO and low ionic kinetics diffusion while cycling, which largely limits its application in solid-state batteries. Modifying the LTO lattice or crystal structure is one way to mitigate this problem. This study shows the coexistence of two main components, Ti4+ and Ti3+, in the crystal structure of LTO developed with a modified atomic layer deposition. The X-ray photoelectron spectroscopy analysis shows calcination under reducing gas, introduces Ti3+ and oxygen vacancies into the Li4Ti5O12 crystal, which can affect the electronic conductivity of LTO. Furthermore, we show how different substrates acting as diffusion barriers affect the film properties.

Details

Original languageEnglish
Article number139694
JournalThin solid films
Volume768
Publication statusPublished - 1 Mar 2023
Peer-reviewedYes

Keywords

Sustainable Development Goals

Keywords

  • Anode material, Atomic layer deposition (ALD), Diffusion barrier, Lithium titanate (LTO), Spinel-LTO, X-ray photoelectron spectroscopy (XPS)