Random quaternary ammonium Diels-Alder poly(phenylene) copolymers for improved vanadium redox flow batteries

Timothy D. Largier, Christopher J Cornelius

Research output: Contribution to journalArticle

17 Scopus citations

Abstract

This study analyzes the effect of quaternary ammonium homopolymer (AmPP) and ionic and non-ionic random unit copolymerization (AmPP-PP) of Diels-Alder poly(phenylene)s on electrochemical and transport properties, vanadium redox flow battery performance, and material stability. AmPP-PP materials were synthesized with IEC's up to 2.2 meq/g, displaying a carbonate form ion conductivity of 17.3 mS/cm and water uptake of 57.3%. Vanadium ion permeability studies revealed that the random copolymers possess superior charge carrier selectivity. For materials of comparable ion content, at 10 mA/cm2 the random copolymer displayed a 14% increase in coulombic efficiency (CE) corresponding to a 7% increase in energy efficiency. All quaternary ammonium materials displayed ex situ degradation in a 0.5 M V5+ + 5 M H2SO4 solution, with the rate of degradation appearing to increase with IEC. Preliminary studies reveal that the neutralizing counter-ion has a significant effect on VRB performance, proportional to changes in vanadium ion molecular diffusion.

Original languageEnglish (US)
Pages (from-to)149-155
Number of pages7
JournalJournal of Power Sources
Volume352
DOIs
Publication statusPublished - Jan 1 2017

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Keywords

  • Ionomer degradation
  • Quaternary ammonium polyphenylene
  • VO transport
  • Vanadium flow-battery

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Energy Engineering and Power Technology
  • Physical and Theoretical Chemistry
  • Electrical and Electronic Engineering

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