Li Salt Anion Effect on O2 Solubility in an Li–O2 Battery

Abstract

For the promising Li–O2 battery to be commercialized, further understanding of its constituents is needed. This study deals with the role of O2 in Li–O2 batteries, both its influence on electrochemical performance and its solubility in lithium-salt-containing dimethyl sulfoxide (DMSO) electrolytes. Experimentally, the electrochemical performance was evaluated using cylindrical ultramicroelectrodes. Two independent techniques, using a mass spectrometer and an optical sensor, were used to evaluate the O2 solubility, expressed as Henry’s constant. Furthermore, the ionic conductivity, dynamic viscosity, and density were also measured. Density functional theory calculations were made of the interaction energy between O2 and the different species in the electrolytes. When varying O2 partial pressure, the current was larger at high pressures confirming that the O2 concentration is of key importance when studying the kinetics of this system. Compared with neat DMSO, the O2 solubility increased with addition of Li...