The Net Discharge Mechanism of the VB2/Air Battery
Date
2014-11
Authors
Stuart, Jessica
Hohenadel, Amelia
Li, Xuguang
Xiao, Han
Parkey, Jeff
Rhodes, Christopher P.
Licht, Stuart
Journal Title
Journal ISSN
Volume Title
Publisher
IOP Science
Abstract
The electrochemical discharge of VB2</sub> is a unique process that involves the multiple electron per molecule oxidation of the tetravalent transition metal ion, V (+4 → +5), and each of the two borons 2×B (−2 → +3), corresponding to a net 11 electron discharge mechanism of the VB2/air cell as described by the overall cell reaction: VB2 + 11/4O2 → B2O3 + ½ V2O5. However, in the presence of alkaline electrolytes, the discharge products include alkali salts associated with vanadaic and boric acid. In this study, we used FTIR, XRD, and coulombic efficiency measurements to probe the discharge products of high capacity cells and isolate KVO3 as the principal vanadium discharge product. Additionally, we show that K2B4O7 is the probable borate product. From FTIR analysis in KOH electrolyte, it is evident that the alkaline VB2/air discharge reaction is: VB2 + 11/4O2 + 2KOH → ½ K2B4O7 + KVO3 + H2O. XPS shows that the surface structure of nanoscopic VB2 is very different from macroscopic VB2, which may contribute to the improved electrochemical properties of the nanoscopic material. The understanding of the discharge process and factors affecting performance contribute to furthering the development of extremely high capacity VB2/air batteries that utilize multi-electron processes.
Description
Keywords
electrochemical discharge, multi-electron processes, VB2air/battery, Chemistry and Biochemistry
Citation
Stuart, J., Hohenadel, A., Li, X., Xiao, H., Parkey, J., Rhodes, C., & Licht, S. (2014). The net discharge mechanism of the VB2/air battery. Journal of The Electrochemical Society, 162(1), A192.
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Rights Holder
© 2014 The Author(s).
Rights License
This work is licensed under a Creative Commons Attribution 4.0 International License.