Stabilisation of the superoxide anion in bis(fluorosulfonyl)imide (FSI) ionic liquid by small chain length phosphonium cations: Voltammetric, DFT modelling and spectroscopic perspectives
Artikel i vetenskaplig tidskrift, 2021

Ionic liquids (ILs) containing the bis(fluorosulfonyl)imide anion, FSI, have been investigated as electrolytes for metal-air batteries. Full chemical reversibility is found for the reduction of oxygen to superoxide at 60 degrees C under short time scale conditions of cyclic voltammetry at a glassy carbon electrode when the IL contains the small chain length triisobutyl(methyl)phosphonium rather than a pyrrolidinium cation. DFT calculations suggest that this is a consequence of the higher ion pair association energy and shorter intermolecular distance associated with the interaction of the superoxide anion with the phosphonium cation. Stabilization on longer timescales was also established by spectroscopic techniques when the phosphonium based ILs were exposed to KO2. Studies on superoxide stability in related ionic liquids containing the triisobutyl(methyl)phosphonium cation with the fluorosulfonyl(trifluoromethanesulfonyl)imide, FTFSI, or bis(trifluoromethanesulfonyl)imide, TFSI, anions are also reported.Y

Phosphonium cation

Oxygen reduction reaction

Ionic liquids

Enhancement of superoxide stability

Metal-air batteries

Författare

Laura Garcia-Quintana

Deakin University

Erlendur Jonsson

Chalmers, Fysik, Materialfysik

Ruhamah Yunis

Deakin University

Queensland University of Technology (QUT)

Douglas R. MacFarlane

Monash University

Maria Forsyth

Deakin University

Alan M. Bond

Monash University

Patrick C. Howlett

Deakin University

Cristina Pozo-Gonzalo

Deakin University

Electrochemistry Communications

1388-2481 (ISSN)

Vol. 127 107029

Ämneskategorier

Oorganisk kemi

Fysikalisk kemi

Annan kemi

DOI

10.1016/j.elecom.2021.107029

Mer information

Senast uppdaterat

2021-06-29