Infrared Spectroscopy Studies on Stability of Dimethyl Sulfoxide for Application in Li-air Battery

MOZHZHUKHINA, NATALIIA; MÉNDEZ DE LEO, LUCILA P.; CALVO, ERNESTO J.

JOURNAL OF PHYSICAL CHEMISTRY C

AMER CHEMICAL SOC

Lugar: Washington; Año: 2013 vol. 117 p. 18375 - 18380

1932-7447

In-situ infrared subtractive normalized Fourier transform infrared spectroscopy (SNIFTIRS) experiments simultaneous to the electro reduction of oxygen on gold and platinum cathodes in LiPF6 DMSO electrolyte have shown that the solvent is stable with respect to nucleophillic attack by the electro generated superoxide radical anion. However, long term experiments with KO2 solutions in DMSO have shown a slow formation of dimethyl sulfone. Evidence of dimethyl sulfone formation by anodic oxidation of DMSO above 4.2 V (Li/Li+) in the presence of traces of water has been obtained on gold. On platinum this unwanted reaction in the charging cycle of lithium air battery takes place at lower potentials, i.e. 3.5 V.