%0 Journal Article
%T Friedel¨CCrafts Crosslinked Highly Sulfonated Polyether Ether Ketone (SPEEK) Membranes for a Vanadium/Air Redox Flow Battery
%A G¨¦raldine Merle
%A Filipoi Carmen Ioana
%A Dan Eugen Demco
%A Michel Saakes
%A Seyed Schwan Hosseiny
%J Membranes
%D 2014
%I MDPI AG
%R 10.3390/membranes4010001
%X Highly conductive and low vanadium permeable crosslinked sulfonated poly(ether ether ketone) (cSPEEK) membranes were prepared by electrophilic aromatic substitution for a Vanadium/Air Redox Flow Battery (Vanadium/Air-RFB) application. Membranes were synthesized from ethanol solution and crosslinked under different temperatures with 1,4-benzenedimethanol and ZnCl 2 via the Friedel¨CCrafts crosslinking route. The crosslinking mechanism under different temperatures indicated two crosslinking pathways: (a) crosslinking on the sulfonic acid groups; and (b) crosslinking on the backbone. It was observed that membranes crosslinked at a temperature of 150 ˇăC lead to low proton conductive membranes, whereas an increase in crosslinking temperature and time would lead to high proton conductive membranes. High temperature crosslinking also resulted in an increase in anisotropy and water diffusion. Furthermore, the membranes were investigated for a Vanadium/Air Redox Flow Battery application. Membranes crosslinked at 200 ˇăC for 30 min with a molar ratio between 2:1 (mol repeat unit:mol benzenedimethanol) showed a proton conductivity of 27.9 mS/cm and a 100 times lower VO 2+ crossover compared to Nafion.
%K cation exchange membrane
%K redox flow battery
%K membrane technology
%U http://www.mdpi.com/2077-0375/4/1/1