Multifunctional imidazolium-based ionic liquid crystal as a catalytic additive for enhancing Li-O2 battery performance

Résumé fourni par la source

The lithium–oxygen ( ) battery offers an exceptional energy density but suffers from poor reversibility and electrolyte degradation due to large charge overpotentials. In this work, these challenges are addressed by introducing the ionic liquid crystal (ILC) 1-hexadecyl-3-methylimidazolium bromide, , as a multifunctional additive in an electrolyte composed of dimethyl sulfoxide (DMSO) with 0.100 M lithium perchlorate (LiClO 4 ). The ILC is a soluble catalyst that functions simultaneously as a stabilizing agent and redox mediator, reducing charge overpotentials and suppressing side reactions. This multifunction enhances catalytic activity and battery life. At a diluted ILC concentration of 0.035 M and fixed capacity of 1 000 mA⋅h/g, the cyclability of the battery improves significantly over 50 cycles. In comparison, cells using DMSO/LiClO 4 and with lithium bromide (LiBr) as redox mediator achieve only 18 and 7 cycles, respectively. In addition, is observed to promote the protection of the Li anode through the formation of a solid electrolyte interphase (SEI) layer. To support these experimental findings, molecular dynamics and density functional theory simulations elucidate the species distribution and structure of the electrode–electrolyte interphase. In general, this study provides information on electrolyte engineering for batteries, highlighting the potential of redox active, long-alkyl-chain additives in advanced energy-storage systems.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.