Surface Study of Lithium-Air Battery Oxygen Cathodes in Different Solvent-Electrolyte pairs

The O2/Li2O2 electrode reaction has been studied on low surface area Au electrodes in three solvent-electrolyte pairs (0.1 M LiPF6/DMSO, LiPF6/ACN, and LiBF4/ACN) using an electrochemical cell coupled to UHV XPS spectrometer, EQCM, AFM, and DEMS. The XPS spectra of the surfaces after treatment at se...

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Bibliographic Details
Authors: Marchini, Florencia, Herrera, Santiago Esteban, Torres, Walter Ramon, Tesio, Alvaro Yamil, Williams, Federico José, Calvo, Ernesto Julio
Format: article
Status:Published version
Publication Date:2015
Country:Argentina
Institution:Consejo Nacional de Investigaciones Científicas y Técnicas
Repository:CONICET Digital (CONICET)
Language:English
OAI Identifier:oai:ri.conicet.gov.ar:11336/58897
Online Access:http://hdl.handle.net/11336/58897
Access Level:Open access
Keyword:Litio
Oxigeno
Xps
Dmso
https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
Description
Summary:The O2/Li2O2 electrode reaction has been studied on low surface area Au electrodes in three solvent-electrolyte pairs (0.1 M LiPF6/DMSO, LiPF6/ACN, and LiBF4/ACN) using an electrochemical cell coupled to UHV XPS spectrometer, EQCM, AFM, and DEMS. The XPS spectra of the surfaces after treatment at selected electrode potentials for the O2 reduction and reoxidation of the surface show the presence of C and S from solvent decomposition and of F and P from electrolyte decomposition. Furthermore, Li 1s and O 1s peaks due to Li2O2 and decomposition products such as carbonate, organics, LiF, high oxidation sulfur, and phosphorus compounds were also observed. Using ACN instead of DMSO results in less solvent decomposition, whereas using LiBF4 results in less electrolyte decomposition. XPS, AFM, and EQCM show that O2 reduction products removal only takes place at very high overpotentials. In agreement with XPS which shows removal of carbonate surface species, DEMS confirms evolution of CO2 and consumption of O2 at 4.5 V, but LiF cannot be removed completely in a round trip of the Li-O2 battery cathode.