Durable and Efficient PTFE Sandwiched SPEEK Membrane for Vanadium Flow Batteries
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Updated: Mar 15, 2026

A Protocol for Electrochemical Evaluations and State of Charge Diagnostics of a Symmetric Organic Redox Flow Battery
Published on: February 13, 2017
1School of Applied Chemistry and Biological Technology, Shenzhen Polytechnic , Shenzhen 518055, China.
Abstract:
To overcome the poor cycling stability of sulfonated poly(ether ether ketone) (SPEEK) membrane in vanadium flow batteries (VFB), we demonstrate a facile and effective sandwich design by using hydrophilic porous poly(tetrafluoroethylene) (PTFE) films as a stress protective and electrolyte buffer layer for SPEEK membrane. VFB based on this novel sandwich PTFE/SPEEK/PTFE membrane exhibits super long-life properties, which can steadily run (98.5% of Coulombic efficiency and 85.0% of energy efficiency @ 80 mA cm(-2)) with 2.0 M vanadium electrolyte for more than 1000 cycles. This simple and powerful strategy may also be applied to other nonfluoride membranes.
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