Lactone-Based Liquid Electrolytes for Fluoride Shuttle Batteries

Rechargeable secondary batteries operating through fluoride-ion shuttling between the positive and negative electrodes, referred to as fluoride shuttle (FSBs), offer a potentially promising solution overcoming energy-density limitations of current lithium-ion battery systems. However, there are many technical issues that need be resolved achieve high-quality fluoride-carrying electrolytes ensure reversible transformations metal its counterpart at both electrodes. Here, we introduce novel lactone-based liquid consisting either CsF or KF, which prepared by solvent substitution method. Although maximum concentration achieved method is approximately 0.05 M, these systems behave strong where CsF(KF) almost fully dissociated into Cs + (K ) F ? ions give ionic conductivity 0.8 mS.cm ?1 . Hence, supports electrochemically active can drive metal/metal-fluoride room temperature for wide range irreversible reductive reactions solvent, also promoted ions, limit currently potential window ?1.5 V vs standard hydrogen electrode.