# Monitoring and quantifying morphological and structural changes in electrode materials under operando conditions

Fehse, Marcus, Hogan, Matteo P., Pang, Sally Hiu-Tung, Blackman, Oliver, Kelder, Erik M., Longo, Alessandro, Alfredsson, Maria (2020) Monitoring and quantifying morphological and structural changes in electrode materials under operando conditions. Journal of Power Sources, 478 . Article Number 228685. ISSN 0378-7753. (doi:10.1016/j.jpowsour.2020.228685) (KAR id:83325)

X-ray absorption and small-angle x-ray scattering spectra were simultaneously acquired under operando conditions in a joined technique approach, for the first time applied in the field of energy storage materials. This approach allows one to closely follow the electronic and local structure evolution, as well as monitor and quantify the morphological and nanostructural changes occurring during electrochemical cycling. Here we demonstrate its potential on the example of doped and non-doped Fe$$_2$$O$$_3$$ anode material vs. Li. Our results reveal that upon discharge Fe$$^{3+}$$ is gradually reduced to the metallic state and segregated as nanoparticles. For the relithiation reaction, upon subsequent charge, we observe improved reversibility for the Sr-doped compared to non-doped and Ca-doped Fe$$_2$$O$$_3$$. We highlight that this combined technique approach is a reliable, facile and powerful tool to investigate electrode materials under realistic cycling condition. It provides an unbiased and holistic picture of the morphological and structural changes occurring during operation, which allows for adequate material tailoring.
Item Type: Article 10.1016/j.jpowsour.2020.228685 Conversion reaction; Small-angle x-ray scattering; X-ray absorption spectroscopy; Operando characterization; Fe$$_2$$O$$_3$$ Q Science Divisions > Division of Natural Sciences > School of Physical Sciences Maria Alfredsson 08 Oct 2020 10:18 UTC 16 Feb 2021 14:15 UTC https://kar.kent.ac.uk/id/eprint/83325 (The current URI for this page, for reference purposes) https://orcid.org/0000-0002-2843-1641