Operando Observation of the Gold–Electrolyte Interface in Li–O2 Batteries

Observing the cathode interface in Li–O2 batteries during cycling is necessary to improve our understanding of discharge product formation and evolution in practical cells. In this work a gold electrode surface is monitored by operando surface-enhanced Raman spectroscopy during typical discharge and...

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Bibliographic Details
Published in:ACS applied materials & interfaces 2014-11, Vol.6 (21), p.19017-19025
Main Authors: Gittleson, Forrest S, Ryu, Won-Hee, Taylor, André D
Format: Article
Language:English
Online Access:Get full text
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Summary:Observing the cathode interface in Li–O2 batteries during cycling is necessary to improve our understanding of discharge product formation and evolution in practical cells. In this work a gold electrode surface is monitored by operando surface-enhanced Raman spectroscopy during typical discharge and charge cycling. During discharge, we observe the precipitation of stable and reversible lithium superoxide (LiO2), in contrast to reports that suggest it is a mere intermediate in the formation of lithium peroxide (Li2O2). Some LiO2 is further reduced to Li2O2 producing a coating of insulating discharge products that renders the gold electrode inactive. Upon charging, a superficial layer of these species (∼1 nm) are preferentially oxidized at low overpotentials (
ISSN:1944-8244
1944-8252
DOI:10.1021/am504900k