Averting H + -Mediated Charge Storage Chemistry Stabilizes the High Output Voltage of LiMn 2 O 4 -Based Aqueous Battery.

Autor: Bhadra A; School of Chemical Engineering, UNSW Sydney, Kensington, NSW, 2052, Australia., Swathilakshmi S; Department of Materials Engineering, Indian Institute of Science, Bengaluru, 560012, India., Mittal U; School of Chemistry, UNSW Sydney, Kensington, NSW, 2052, Australia., Sharma N; School of Chemistry, UNSW Sydney, Kensington, NSW, 2052, Australia., Sai Gautam G; Department of Materials Engineering, Indian Institute of Science, Bengaluru, 560012, India., Kundu D; School of Chemical Engineering, UNSW Sydney, Kensington, NSW, 2052, Australia.; School of Mechanical and Manufacturing Engineering, UNSW Sydney, Kensington, NSW, 2052, Australia.
Jazyk: angličtina
Zdroj: Small methods [Small Methods] 2024 Apr 19, pp. e2400070. Date of Electronic Publication: 2024 Apr 19.
DOI: 10.1002/smtd.202400070
Abstrakt: H + co-intercalation chemistry of the cathode is perceived to have damaging consequences on the low-rate and long-term cycling of aqueous zinc batteries, which is a critical hindrance to their promise for stationary storage applications. Herein, the thermodynamically competitive H + storage chemistry of an attractive high-voltage cathode LiMn 2 O 4 is revealed by employing operando and ex-situ analytical techniques together with density functional theory-based calculations. The H + electrochemistry leads to the previously unforeseen voltage decay with cycling, impacting the available energy density, particularly at lower currents. Based on an in-depth investigation of the effect of the Li + to Zn 2+ ratio in the electrolyte on the charge storage mechanism, a purely aqueous and low-salt concentration electrolyte with a tuned Li + /Zn 2+ ratio is introduced to subdue the H + -mediated charge storage kinetically, resulting in a stable voltage output and improved cycling stability at both low and high cathode loadings. Synchrotron X-ray diffraction analysis reveals that repeated H + intercalation triggers an irreversible phase transformation leading to voltage decay, which is averted by shutting down H + storage. These findings unveiling the origin and impact of the deleterious H + -storage, coupled with the practical strategy for its inhibition, will inspire further work toward this under-explored realm of aqueous battery chemistry.
(© 2024 The Authors. Small Methods published by Wiley‐VCH GmbH.)
Databáze: MEDLINE
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