Soluble TTF catalyst for the oxidation of cathode products in Li-Oxygen battery: A chemical scavenger

Abstract

One of the challenges for the success of electric vehicles is to achieve a non aqueous Li-O2 battery efficient in the oxidation of solid Li2O2 during battery charging. Bruce et al. have proposed that soluble tetrathiofulvalene (TTF) in the electrolyte, makes it possible to recharge the battery at high current densities and low over-potential. We disclose here a detailed study of Li2O2 and solvent degradation products oxidation on gold electrode in 0.1 M LiPF6 DMSO electrolyte with soluble TTF using a variety of techniques: rotating ring disk electrode (RRDE), scanning electrochemical microscopy (SECM), electrochemical quartz crystal microbalance (EQCM) and atomic force microscopy (AFM). The experimental evidence demonstrates that it is possible recover a clean Au surface using TTF as a soluble catalyst that titrates the surface products formed during the O2 reduction.