A high-rate and high-efficiency molten-salt sodium–oxygen battery
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d2ee01774a.pdf
Description
Published version
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Checksum (MD5)
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Author(s)
Zhu, Yun Guang
Leverick, Graham
Accogli, Alessandra
Gordiz, Kiarash
Zhang, Yirui
Shao-Horn, Yang
Date Issued
September 27, 2022
Journal
Energy & Environmental Science
Publisher
Royal Society of Chemistry (RSC)
Citation
Zhu, Yun Guang, Leverick, Graham, Accogli, Alessandra, Gordiz, Kiarash, Zhang, Yirui et al. 2022. "A high-rate and high-efficiency molten-salt sodium–oxygen battery." Energy & Environmental Science.
Version
Final published version
Abstract
Alkali metal–oxygen batteries can provide greater specific energy than Li-ion batteries but often suffer
from low power density, cycleability, and energy efficiency due to the sluggish kinetics of the oxygen
electrode and parasitic reactions at both the oxygen and alkali metal electrodes. In this study, we
demonstrated a molten-salt Na–O2 battery operating at 443 K with high areal energy (33 mW h
cm2
geo) and power densities (19 mW cm2
geo), with high energy efficiency (B90% at 5 mA cm2
geo),
and stable cycling (400 cycles with no capacity loss). Raman, pressure tracking and titration measurements were used to show that the dominant discharge product is Na2O2. Moreover, the redox activity of
nitrate anions in the molten salt was found to be critical to enable the formation of Na2O2. Through
18O-labeling experiments as well as discharging Na–Ar cells, we demonstrated that the discharge
reaction occurs via the electrochemical reduction of NaNO3 to Na2O and NaNO2, where chemical reactions with O2 lead to the formation of Na2O2 from Na2O, and the regeneration of NaNO3 from NaNO2.
MIT Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Massachusetts Institute of Technology. Department of Mechanical Engineering
Massachusetts Institute of Technology. Research Laboratory of Electronics
Massachusetts Institute of Technology. Electrochemical Energy Laboratory
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Creative Commons Attribution NonCommercial License 3.0
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DOI of Published Version
https://doi.org/10.1039/d2ee01774a
