Polytetrafluoroethylene Modified Nafion Membranes by Magnetron Sputtering for Vanadium Redox Flow Batteries

Commercial Nafion membranes have been widely used for vanadium redox flow batteries (VRFB) but with relatively low ion selectivity. A chemical method is commonly employed to modify the organic membranes, whereas physical approaches are rarely reported in view of less compatibility species. In this study, an ultrathin polytetrafluoroethylene (PTFE) film than 30 nm deposited onto substrates by radio frequency magnetron sputtering form PTFE@Nafion composite membranes. The PTFE layer hydrophobic and inert feature enhances dimensional stability selectivity VRFB single cell optimized membrane exhibits a better self-discharge property that 212 (i.e., 201.2 vs. 18.6 h), due higher 21.191 × 104 11.054 S min cm–3). also show discharge capacity retention over entire 100 cycles. results indicate alternative feasible route tailor via surface modification functionalization.