Operando APXPS for direct probing of Li ion battery LCO electrode/electrolyte interface chemistry during lithiation/delithiation
(2025) In Journal of Materials Chemistry A 13(26). p.20568-20577- Abstract
The real-time interface chemistry between the lithium cobalt oxide (LCO) working electrode and the LiClO4/propylene carbonate (PC) electrolyte is investigated during lithiation/delithiation using dip-and-pull ambient pressure photoelectron spectroscopy (APXPS). The APXPS results appear to exhibit the seldom discussed Co2+ state in the LCO structure, where the operando measurements indicate electron transfer among Co2+, Co3+, and Co4+ states. Specifically, the lithiation of LCO reduces the Co4+ state to both Co3+ and Co2+ states, where, as a function of voltage, reduction to the Co2+ state is initially more pronounced followed by... (More)
The real-time interface chemistry between the lithium cobalt oxide (LCO) working electrode and the LiClO4/propylene carbonate (PC) electrolyte is investigated during lithiation/delithiation using dip-and-pull ambient pressure photoelectron spectroscopy (APXPS). The APXPS results appear to exhibit the seldom discussed Co2+ state in the LCO structure, where the operando measurements indicate electron transfer among Co2+, Co3+, and Co4+ states. Specifically, the lithiation of LCO reduces the Co4+ state to both Co3+ and Co2+ states, where, as a function of voltage, reduction to the Co2+ state is initially more pronounced followed by Co3+ formation. In addition, a delay in surface delithiation is observed during the reverse potential steps. This is discussed in terms of overpotential at the interface measurement position as a consequence of the dip-and-pull setup for this experiment. Finally, the shifts in the apparent binding energies of the spectral features corresponding to the electrolyte and LCO at their interface show that the electrochemical potentials at delithiation voltage steps are different from the lithiation steps at the same applied voltages. This further explains the non-responsive delithiation. The BE shift observed from the LCO surface is argued to be dominantly due to the semi-conductive nature of the sample. Overall, this article shows the importance of operando APXPS for probing non-equilibrium states in battery electrodes for understanding electron transfer in the reactions.
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- author
- organization
- publishing date
- 2025-05-21
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Materials Chemistry A
- volume
- 13
- issue
- 26
- pages
- 10 pages
- publisher
- Royal Society of Chemistry
- external identifiers
-
- scopus:105007444373
- ISSN
- 2050-7488
- DOI
- 10.1039/d5ta01654a
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2025 The Royal Society of Chemistry.
- id
- 2f910de8-0b39-47d1-b8fe-a505e6d13033
- date added to LUP
- 2025-12-18 13:43:59
- date last changed
- 2025-12-18 13:44:44
@article{2f910de8-0b39-47d1-b8fe-a505e6d13033,
abstract = {{<p>The real-time interface chemistry between the lithium cobalt oxide (LCO) working electrode and the LiClO<sub>4</sub>/propylene carbonate (PC) electrolyte is investigated during lithiation/delithiation using dip-and-pull ambient pressure photoelectron spectroscopy (APXPS). The APXPS results appear to exhibit the seldom discussed Co<sup>2+</sup> state in the LCO structure, where the operando measurements indicate electron transfer among Co<sup>2+</sup>, Co<sup>3+</sup>, and Co<sup>4+</sup> states. Specifically, the lithiation of LCO reduces the Co<sup>4+</sup> state to both Co<sup>3+</sup> and Co<sup>2+</sup> states, where, as a function of voltage, reduction to the Co<sup>2+</sup> state is initially more pronounced followed by Co<sup>3+</sup> formation. In addition, a delay in surface delithiation is observed during the reverse potential steps. This is discussed in terms of overpotential at the interface measurement position as a consequence of the dip-and-pull setup for this experiment. Finally, the shifts in the apparent binding energies of the spectral features corresponding to the electrolyte and LCO at their interface show that the electrochemical potentials at delithiation voltage steps are different from the lithiation steps at the same applied voltages. This further explains the non-responsive delithiation. The BE shift observed from the LCO surface is argued to be dominantly due to the semi-conductive nature of the sample. Overall, this article shows the importance of operando APXPS for probing non-equilibrium states in battery electrodes for understanding electron transfer in the reactions.</p>}},
author = {{Liu, Qianhui and Ericson, Tove and Temperton, Robert and Källquist, Ida and Lindgren, Fredrik and King, Laura and Križan, Alenka and Browning, Katie L. and Crumlin, Ethan J. and Veith, Gabriel M. and Hahlin, Maria}},
issn = {{2050-7488}},
language = {{eng}},
month = {{05}},
number = {{26}},
pages = {{20568--20577}},
publisher = {{Royal Society of Chemistry}},
series = {{Journal of Materials Chemistry A}},
title = {{Operando APXPS for direct probing of Li ion battery LCO electrode/electrolyte interface chemistry during lithiation/delithiation}},
url = {{http://dx.doi.org/10.1039/d5ta01654a}},
doi = {{10.1039/d5ta01654a}},
volume = {{13}},
year = {{2025}},
}