Li Salt Anion Effect on O2 Solubility in an Li-O2 Battery
Journal article, 2018

For the promising Li-O 2 battery to be commercialized, further understanding of its constituents is needed. This study deals with the role of O 2 in Li-O 2 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 O 2 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 O 2 and the different species in the electrolytes. When varying O 2 partial pressure, the current was larger at high pressures confirming that the O 2 concentration is of key importance when studying the kinetics of this system. Compared with neat DMSO, the O 2 solubility increased with addition of LiTFSI and decreased with addition of LiClO 4 , indicating that the salt influences the solubility. This solubility trend is best explained in terms of apparent molar volume and interaction energy between O 2 and the salt anion. In conclusion, this study shows the importance of O 2 concentration, not just its partial pressure, and that the choice of Li salt can make this concentration increase or decrease.

Author

Jonas Lindberg

Royal Institute of Technology (KTH)

Balázs Endródi

Royal Institute of Technology (KTH)

University of Szeged / Szegedi Tudományegyetem

Gustav Åvall

Chalmers, Physics, Condensed Matter Physics

Patrik Johansson

Chalmers, Physics, Condensed Matter Physics

Ann Cornell

Royal Institute of Technology (KTH)

Göran Lindbergh

Royal Institute of Technology (KTH)

Journal of Physical Chemistry C

1932-7447 (ISSN) 1932-7455 (eISSN)

Vol. 122 4 1913-1920

Subject Categories

Condensed Matter Physics

DOI

10.1021/acs.jpcc.7b09218

More information

Latest update

2/28/2018