Effects of the Electrolyte Concentration on the Nature of the Solid Electrolyte Interphase of a Lithium Metal Electrode

Justine Touja (1) , Parnian Salembier Peyrovi (2) , Yann Tison (2) , Hervé Martinez (2) , Olinda Gimello (1) , Nicolas Louvain (1) , Lorenzo Stievano (1, 3) , L. Monconduit (1, 3)

1 ICGM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier
2 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux
3 RS2E - Réseau sur le stockage électrochimique de l'énergie

The need of more powerful systems with higher energy density raises a lot of interest in lithium metal batteries (LMBs). As LMBs suffer from safety concerns due to the dendrite growth, several strategies have been studied to limit this growth. Using a highly concentrated electrolyte allows a homogeneous lithium plating that delays the formation of dendrites. Herein, different techniques are used in order to better understand the beneficial role of the salt concentration in the lithium plating/stripping. Operando Fourier transform infrared spectroscopy highlights the better reversibility of the Li+ solvation in the 5 M lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in 1,2-dioxolane/1,3-dimethoxyethane electrolyte in comparison with the 1 M electrolyte. This obviously leads to different electrolyte decompositions during the lithium plating/stripping and changes the nature of the electrode solid electrolyte interphase (SEI) depending on the salt concentration. Gas chromatography coupled with mass spectrometry as well as X-ray photoelectron spectroscopy confirms that with the 5 M LiTFSI electrolyte the salt is preferentially reduced during the plating/stripping, leading to a more inorganic SEI on the lithium metal electrode.

Mots clés: electrolytes; lithium anodes; lithium batteries; metal anodes; solid electrolyte interphase

Domaines: Matériaux; Chimie analytique; Polymères; Chimie théorique et/ou physique

Justine Touja, Parnian Salembier Peyrovi, Yann Tison, Hervé Martinez, Olinda Gimello, et al.. Effects of the Electrolyte Concentration on the Nature of the Solid Electrolyte Interphase of a Lithium Metal Electrode. Energy Technology, 2023, 11 (1), pp.2201037. ⟨10.1002/ente.202201037⟩. ⟨hal-03884752⟩