---
_id: '7275'
abstract:
- lang: eng
text: Aprotic alkali metal–oxygen batteries require reversible formation of metal
superoxide or peroxide on cycling. Severe parasitic reactions cause poor rechargeability,
efficiency, and cycle life and have been shown to be caused by singlet oxygen
(1O2) that forms at all stages of cycling. However, its formation mechanism remains
unclear. We show that disproportionation of superoxide, the product or intermediate
on discharge and charge, to peroxide and oxygen is responsible for 1O2 formation.
While the overall reaction is driven by the stability of peroxide and thus favored
by stronger Lewis acidic cations such as Li+, the 1O2 fraction is enhanced by
weak Lewis acids such as organic cations. Concurrently, the metal peroxide yield
drops with increasing 1O2. The results explain a major parasitic pathway during
cell cycling and the growing severity in K–, Na–, and Li–O2 cells based on the
growing propensity for disproportionation. High capacities and rates with peroxides
are now realized to require solution processes, which form peroxide or release
O2via disproportionation. The results therefore establish the central dilemma
that disproportionation is required for high capacity but also responsible for
irreversible reactions. Highly reversible cell operation requires hence finding
reaction routes that avoid disproportionation.
article_processing_charge: No
article_type: original
author:
- first_name: Eléonore
full_name: Mourad, Eléonore
last_name: Mourad
- first_name: Yann K.
full_name: Petit, Yann K.
last_name: Petit
- first_name: Riccardo
full_name: Spezia, Riccardo
last_name: Spezia
- first_name: Aleksej
full_name: Samojlov, Aleksej
last_name: Samojlov
- first_name: Francesco F.
full_name: Summa, Francesco F.
last_name: Summa
- first_name: Christian
full_name: Prehal, Christian
last_name: Prehal
- first_name: Christian
full_name: Leypold, Christian
last_name: Leypold
- first_name: Nika
full_name: Mahne, Nika
last_name: Mahne
- first_name: Christian
full_name: Slugovc, Christian
last_name: Slugovc
- first_name: Olivier
full_name: Fontaine, Olivier
last_name: Fontaine
- first_name: Sergio
full_name: Brutti, Sergio
last_name: Brutti
- first_name: Stefan Alexander
full_name: Freunberger, Stefan Alexander
id: A8CA28E6-CE23-11E9-AD2D-EC27E6697425
last_name: Freunberger
orcid: 0000-0003-2902-5319
citation:
ama: Mourad E, Petit YK, Spezia R, et al. Singlet oxygen from cation driven superoxide
disproportionation and consequences for aprotic metal–O2 batteries. Energy
& Environmental Science. 2019;12(8):2559-2568. doi:10.1039/c9ee01453e
apa: Mourad, E., Petit, Y. K., Spezia, R., Samojlov, A., Summa, F. F., Prehal, C.,
… Freunberger, S. A. (2019). Singlet oxygen from cation driven superoxide disproportionation
and consequences for aprotic metal–O2 batteries. Energy & Environmental
Science. RSC. https://doi.org/10.1039/c9ee01453e
chicago: Mourad, Eléonore, Yann K. Petit, Riccardo Spezia, Aleksej Samojlov, Francesco
F. Summa, Christian Prehal, Christian Leypold, et al. “Singlet Oxygen from Cation
Driven Superoxide Disproportionation and Consequences for Aprotic Metal–O2 Batteries.”
Energy & Environmental Science. RSC, 2019. https://doi.org/10.1039/c9ee01453e.
ieee: E. Mourad et al., “Singlet oxygen from cation driven superoxide disproportionation
and consequences for aprotic metal–O2 batteries,” Energy & Environmental
Science, vol. 12, no. 8. RSC, pp. 2559–2568, 2019.
ista: Mourad E, Petit YK, Spezia R, Samojlov A, Summa FF, Prehal C, Leypold C, Mahne
N, Slugovc C, Fontaine O, Brutti S, Freunberger SA. 2019. Singlet oxygen from
cation driven superoxide disproportionation and consequences for aprotic metal–O2
batteries. Energy & Environmental Science. 12(8), 2559–2568.
mla: Mourad, Eléonore, et al. “Singlet Oxygen from Cation Driven Superoxide Disproportionation
and Consequences for Aprotic Metal–O2 Batteries.” Energy & Environmental
Science, vol. 12, no. 8, RSC, 2019, pp. 2559–68, doi:10.1039/c9ee01453e.
short: E. Mourad, Y.K. Petit, R. Spezia, A. Samojlov, F.F. Summa, C. Prehal, C.
Leypold, N. Mahne, C. Slugovc, O. Fontaine, S. Brutti, S.A. Freunberger, Energy
& Environmental Science 12 (2019) 2559–2568.
date_created: 2020-01-15T07:18:04Z
date_published: 2019-08-01T00:00:00Z
date_updated: 2021-01-12T08:12:41Z
day: '01'
ddc:
- '530'
- '541'
- '540'
doi: 10.1039/c9ee01453e
extern: '1'
file:
- access_level: open_access
checksum: 94d4cfb2ab0b4c90ef76a7f3cc811feb
content_type: application/pdf
creator: dernst
date_created: 2020-01-30T16:11:05Z
date_updated: 2020-07-14T12:47:55Z
file_id: '7424'
file_name: 2019_EnergyEnvironScienc_Mourad.pdf
file_size: 2888027
relation: main_file
file_date_updated: 2020-07-14T12:47:55Z
has_accepted_license: '1'
intvolume: ' 12'
issue: '8'
language:
- iso: eng
license: https://creativecommons.org/licenses/by-nc/4.0/
month: '08'
oa: 1
oa_version: Published Version
page: 2559-2568
publication: Energy & Environmental Science
publication_identifier:
issn:
- 1754-5692
- 1754-5706
publication_status: published
publisher: RSC
quality_controlled: '1'
status: public
title: Singlet oxygen from cation driven superoxide disproportionation and consequences
for aprotic metal–O2 batteries
tmp:
image: /images/cc_by_nc.png
legal_code_url: https://creativecommons.org/licenses/by-nc/4.0/legalcode
name: Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
short: CC BY-NC (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 12
year: '2019'
...
---
_id: '7302'
abstract:
- lang: eng
text: Understanding charge carrier transport in Li2O2, the storage material in the
non-aqueous Li-O2 battery, is key to the development of this high-energy battery.
Here, we studied ionic transport properties and Li self-diffusion in nanocrystalline
Li2O2 by conductivity and temperature variable 7Li NMR spectroscopy. Nanostructured
Li2O2, characterized by a mean crystallite size of less than 50 nm as estimated
from X-ray diffraction peak broadening, was prepared by high-energy ball milling
of microcrystalline lithium peroxide with μm sized crystallites. At room temperature
the overall conductivity σ of the microcrystalline reference sample turned out
to be very low (3.4 × 10−13 S cm−1) which is in agreement with results from temperature-variable
7Li NMR line shape measurements. Ball-milling, however, leads to an increase of
σ by approximately two orders of magnitude (1.1 × 10−10 S cm−1); correspondingly,
the activation energy decreases from 0.89 eV to 0.82 eV. The electronic contribution
σeon, however, is in the order of 9 × 10−12 S cm−1 which makes less than 10% of
the total value. Interestingly, 7Li NMR lines of nano-Li2O2 undergo pronounced
heterogeneous motional narrowing which manifests in a two-component line shape
emerging with increasing temperatures. Most likely, the enhancement in σ can be
traced back to the generation of a spin reservoir with highly mobile Li ions;
these are expected to reside in the nearest neighbourhood of defects generated
or near the structurally disordered and defect-rich interfacial regions formed
during mechanical treatment.
article_processing_charge: No
article_type: original
author:
- first_name: A.
full_name: Dunst, A.
last_name: Dunst
- first_name: V.
full_name: Epp, V.
last_name: Epp
- first_name: I.
full_name: Hanzu, I.
last_name: Hanzu
- first_name: Stefan Alexander
full_name: Freunberger, Stefan Alexander
id: A8CA28E6-CE23-11E9-AD2D-EC27E6697425
last_name: Freunberger
orcid: 0000-0003-2902-5319
- first_name: M.
full_name: Wilkening, M.
last_name: Wilkening
citation:
ama: Dunst A, Epp V, Hanzu I, Freunberger SA, Wilkening M. Short-range Li diffusion
vs. long-range ionic conduction in nanocrystalline lithium peroxide Li2O2—the
discharge product in lithium-air batteries. Energy & Environmental Science.
2014;7(8):2739-2752. doi:10.1039/c4ee00496e
apa: Dunst, A., Epp, V., Hanzu, I., Freunberger, S. A., & Wilkening, M. (2014).
Short-range Li diffusion vs. long-range ionic conduction in nanocrystalline lithium
peroxide Li2O2—the discharge product in lithium-air batteries. Energy &
Environmental Science. RSC. https://doi.org/10.1039/c4ee00496e
chicago: Dunst, A., V. Epp, I. Hanzu, Stefan Alexander Freunberger, and M. Wilkening.
“Short-Range Li Diffusion vs. Long-Range Ionic Conduction in Nanocrystalline Lithium
Peroxide Li2O2—the Discharge Product in Lithium-Air Batteries.” Energy &
Environmental Science. RSC, 2014. https://doi.org/10.1039/c4ee00496e.
ieee: A. Dunst, V. Epp, I. Hanzu, S. A. Freunberger, and M. Wilkening, “Short-range
Li diffusion vs. long-range ionic conduction in nanocrystalline lithium peroxide
Li2O2—the discharge product in lithium-air batteries,” Energy & Environmental
Science, vol. 7, no. 8. RSC, pp. 2739–2752, 2014.
ista: Dunst A, Epp V, Hanzu I, Freunberger SA, Wilkening M. 2014. Short-range Li
diffusion vs. long-range ionic conduction in nanocrystalline lithium peroxide
Li2O2—the discharge product in lithium-air batteries. Energy & Environmental
Science. 7(8), 2739–2752.
mla: Dunst, A., et al. “Short-Range Li Diffusion vs. Long-Range Ionic Conduction
in Nanocrystalline Lithium Peroxide Li2O2—the Discharge Product in Lithium-Air
Batteries.” Energy & Environmental Science, vol. 7, no. 8, RSC, 2014,
pp. 2739–52, doi:10.1039/c4ee00496e.
short: A. Dunst, V. Epp, I. Hanzu, S.A. Freunberger, M. Wilkening, Energy &
Environmental Science 7 (2014) 2739–2752.
date_created: 2020-01-15T12:17:43Z
date_published: 2014-08-01T00:00:00Z
date_updated: 2021-01-12T08:12:53Z
day: '01'
doi: 10.1039/c4ee00496e
extern: '1'
intvolume: ' 7'
issue: '8'
language:
- iso: eng
month: '08'
oa_version: Published Version
page: 2739-2752
publication: Energy & Environmental Science
publication_identifier:
issn:
- 1754-5692
- 1754-5706
publication_status: published
publisher: RSC
quality_controlled: '1'
status: public
title: Short-range Li diffusion vs. long-range ionic conduction in nanocrystalline
lithium peroxide Li2O2—the discharge product in lithium-air batteries
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 7
year: '2014'
...