title: Detection of Electrochemical Reaction Products from the Sodium-Oxygen Cell with Solid-State23Na NMR Spectroscopy.
abstract: 23Na MAS NMR spectra of sodium-oxygen (Na-O2) cathodes reveals a combination of degradation species: newly observed sodium fluoride (NaF) and the expected sodium carbonate (Na2CO3), as well as the desired reaction product sodium peroxide (Na2O2). The initial reaction product, sodium superoxide (NaO2), is not present in a measurable quantity in the23Na NMR spectra of the cycled electrodes. The reactivity of solid NaO2is probed further, and NaF is found to be formed through a reaction between the electrochemically generated NaO2and the electrode binder, polyvinylidene fluoride (PVDF). The instability of cell components in the presence of desired electrochemical reaction products is clearly problematic and bears further investigation.
authors.affiliation: Department of Chemistry and Chemical Biology, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada.
authors.forename: Zoë E M
authors.initials: ZE
authors.lastname: Reeve
authors.affiliation: Department of Chemistry and Chemical Biology, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Franko
authors.affiliation: Department of Chemistry and Chemical Biology, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada.
authors.forename: Kristopher J
authors.initials: KJ
authors.lastname: Harris
authors.affiliation: Department of Mechanical and Materials Engineering, University of Western Ontario , London, Ontario N6A 5B9, Canada.
authors.forename: Hossein
authors.initials: H
authors.lastname: Yadegari
authors.affiliation: Department of Mechanical and Materials Engineering, University of Western Ontario , London, Ontario N6A 5B9, Canada.
authors.forename: Xueliang
authors.initials: X
authors.lastname: Sun
authors.affiliation: Department of Chemistry and Chemical Biology, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada.
authors.forename: Gillian R
authors.identifier: 0000-0002-7489-3329
authors.initials: GR
authors.lastname: Goward