title: Chemical vs Electrochemical Formation of Li2CO3as a Discharge Product in Li-O2/CO2Batteries by Controlling the Superoxide Intermediate.
abstract: The Li-O2/CO2battery with high capacity has recently been proposed as a new protocol to convert CO2. However, the fundamental mechanism for the reaction still remains hazy. Here, we investigated the discharge processes of Li-O2/CO2(70%/30%) batteries in two solvents, dimethyl sulfoxide (DMSO) and 1,2-dimethoxyethane (DME). During discharge, both solvents initially show the reduction of oxygen. However, afterward, the solvent affects the reaction pathways of superoxide species by solvating Li+with different strength, depending on the so-called donor number. More precisely, the initial formation of CO4•-is favored in DMSO at the expense of lithium superoxide formation that we observed in DME. Despite the different intermediate processes, X-ray diffraction showed that Li2CO3was the final discharge product in both solvents. Moreover, we observed that CO2cannot be reduced within the electrochemical stability window of DMSO and DME.
authors.affiliation: Chimie du Solide et de l'Energie, UMR 8260, Collège de France , 75231, Paris Cedex 05, France.|Sorbonne Universités - UPMC Université Paris 06 , F-75005 Paris, France.
authors.forename: Wei
authors.identifier: http://orcid.org/0000-0002-5496-4097
authors.initials: W
authors.lastname: Yin
authors.affiliation: Chimie du Solide et de l'Energie, UMR 8260, Collège de France , 75231, Paris Cedex 05, France.|Réseau sur le Stockage Electrochimique de l'Energie (RS2E), CNRS FR 3459 , 33 rue Saint Leu, 80039, Amiens Cedex, France.
authors.forename: Alexis
authors.initials: A
authors.lastname: Grimaud
authors.affiliation: Chimie du Solide et de l'Energie, UMR 8260, Collège de France , 75231, Paris Cedex 05, France.|Sorbonne Universités - UPMC Université Paris 06 , F-75005 Paris, France.
authors.forename: Florent
authors.initials: F
authors.lastname: Lepoivre
authors.affiliation: Chimie du Solide et de l'Energie, UMR 8260, Collège de France , 75231, Paris Cedex 05, France.
authors.forename: Chunzhen
authors.identifier: http://orcid.org/0000-0002-0487-0420
authors.initials: C
authors.lastname: Yang
authors.affiliation: Chimie du Solide et de l'Energie, UMR 8260, Collège de France , 75231, Paris Cedex 05, France.|Sorbonne Universités - UPMC Université Paris 06 , F-75005 Paris, France.|Réseau sur le Stockage Electrochimique de l'Energie (RS2E), CNRS FR 3459 , 33 rue Saint Leu, 80039, Amiens Cedex, France.|ALISTORE-European Research Institute , FR CNRS 3104, 80039 Amiens, France.
authors.forename: Jean Marie
authors.initials: JM
authors.lastname: Tarascon