In situ far-infrared spectroscopy of electrochemical interfaces within batteries

In situ spectroscopies are amongst the most important innovations for modern electrochemistry since they are able to deliver precise molecular level views of electrochemical interfaces and reactions. IR spectroscopies, in particular, have been responsible for elucidating the nature of adsorbed species and intermediates in key electrochemical processes such as H2 evolution, O2 reduction, electro-polymerisation and a host of electrocatalytic reactions such as alcohol oxidation. However, few inroads have been made into recording in situ infrared spectra at frequencies <800 cm-1, although it has been demonstrated that spectra can been recorded in the far-IR region for surface metal vibrations, chloride on silver, chloride on Pt and Hg2Cl2 on mercury. This used external reflection making such experiments technically extremely challenging. Recently we have established expertise in electrochemical ATR (attenuated total reflection) measurements (called SEIRAS – surface enhanced infrared absorption spectroscopy) and applied this to studying mechanisms of oxygen (O2) reduction reactions (ORR). ORR represents one of the most fundamental and important reactions in electrochemistry, with applications for this reaction being found in fuel cells, chlor-alkali electrolysis (in which the hydrogen-evolving electrodes are replaced by oxygen/air-depolarised electrodes) and metal-air batteries, the latter being key focus of this new PhD Project. Importantly, we have used SEIRAS to spectroscopically determine that adsorbed superoxide (O2-) exists at appreciable coverage during the ORR in both aqueous and non-aqueous environments, which have facilitated this as a key spectroscopic probe of ORR at metal-air battery cathodes. Within this PhD project the intension is to extend our spectral range below 800 cm-1 which is important since most of the metal-to-adsorbate bonds vibrate at <800 cm-1.
The objectives for the PhD project are: (1) Develop SEIRAS to probe below 800 cm-1. (2) Record and study vibrational spectra of metal-to -superoxide and -peroxide species at model metal-air batteries. (3) Record low frequency IR spectra during in situ formation of battery solid electrolyte interphase (SEI) layers. (4) Extend far-IR SEIRAS to other important electrochemical reactions such as oxide formation, Cl2 evolution (chlor-alkali) and ion adsorption.

Keywords: Energy storage; batteries; infrared spectroscopy; electrochemistry; lithium
Applications are encouraged from highly motivated candidates who have, or expect to have, at least a 2:1 degree or equivalent in Chemistry or related subject.
Applications should be made as soon as possible but no later than 30th June 2019. Informal enquiries are also encouraged and should be addressed to Professor Laurence Hardwick, [Email Address Removed] or Professor Richard Nichols [Email Address Removed].
Some teaching duties may be required.