Radjenovic, Petar M and Hardwick, Laurence J ORCID: 0000-0001-8796-685X
(2018)
Time-resolved SERS study of the oxygen reduction reaction in ionic liquid electrolytes for non-aqueous lithium-oxygen cells.
FARADAY DISCUSSIONS, 206.
pp. 379-392.
Text
Hardwick_Faraday_IL.pdf - Author Accepted Manuscript Download (3MB) |
Abstract
Superoxide (O<sub>2</sub>˙<sup>-</sup>) is the key intermediate formed during oxygen reduction in non-aqueous electrolytes. One significant obstacle towards the realisation of a practical lithium-oxygen (Li-O<sub>2</sub>) battery is electrolyte instability in the presence of radical oxides, principally superoxide. Here we use the Raman active bands of O<sub>2</sub>˙<sup>-</sup> as a diagnostic molecule for probing the influence of the electrolyte on reaction processes and intermediaries at the electrode surface. In situ surface enhanced Raman studies of the interface at a roughened Au electrode with controlled and dynamic surface potentials were performed in two ionic liquids with differing properties: 1-butyl-1-methyl-azepenium bis(trifluoromethanesulfonyl)imide (Aze<sub>14</sub>TFSI), which has a large/soft cation, and triethylsulfonium bis(trifluoromethanesulfonyl)imide (TESTFSI), which has a relatively small/hard and e<sup>-</sup> accepting cation. The counter-cation and potential were seen to significantly influence the radical nature, or Lewis basicity of O<sub>2</sub>˙<sup>-</sup>. The analysis of peak intensities and Stark shifts in O<sub>2</sub>˙<sup>-</sup> related spectral bands allowed for key information on its character and electrolyte interactions to be elucidated. Time-resolved studies of dynamic surface potentials permitted real time observation of the flux and reorientation of ions at the electrode/electrolyte interface.
Item Type: | Article |
---|---|
Depositing User: | Symplectic Admin |
Date Deposited: | 06 Jun 2017 15:29 |
Last Modified: | 19 Jan 2023 07:03 |
DOI: | 10.1039/c7fd00170c |
Related URLs: | |
URI: | https://livrepository.liverpool.ac.uk/id/eprint/3007837 |