Interactions among solvent, anion acceptor, and supporting electrolyte salt in fluoride shuttle battery electrolyte based on nuclear magnetic resonance

Abstract

AbstractFluoride shuttle batteries (FSBs) are promising next‐generation rechargeable batteries. To analyze the detailed local environment in the electrolytes of FSBs, the dynamics of the molecules and ions in an electrolyte, prepared using 2, 4, 6‐trimethoxyboroxine (TMBX)—a liquid‐type anion acceptor, were investigated using nuclear magnetic resonance. The results indicated that TMBX could be mixed with the solvent (bis[2‐(2‐methoxyethoxy)ethyl]ether (tetraglyme, G4)); however, it did not interact with G4. In contrast, when cesium fluoride (CsF) was added to TMBX/G4, TMBX interacted with CsF, and a TMBX‐F− ion was formed. TMBX‐F− interacted and cooperatively diffused with G4.