A new method based on a solution-grafting technique was used to prepare poly(vinylidene fluoride) grafted polystyrene sulfonated acid (PVDF-g-PSSA) proton exchange membrane. Polystyrene is easily grafted into PVDF, which has been treated in KOH solution. There is a linear relationship between the degree of grafting and the treatment time in KOH solution. Fourier transform infrared spectroscopy and differential scanning calorimetry were used to characterize the changes of the membrane’s microstructure after grafting and sulfonation. The conductivity of the solution-grafted PVDF-g-PSSA membranes was investigated by the four-probe dc technique and reached 1.119×10−1 S cm−1 at 25°C. Gas chromatographic studies show that the methanol permeability of the PVDF-g-PSSA membrane is almost one order of magnitude lower than that of a Nafion-112 membrane. © 2003 The Electrochemical Society. All rights reserved.

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Water loss of the gel polymer electrolytes (GPEs) and dendrites growth on Zn anode are overriding obstacles to applying flexible zinc‐air batteries (ZABs) for wearable electronic devices. Nearly all previous efforts aim at developing novel GPEs with enhanced water retention and therefore elongate their lifespan. Herein, a facile interface engineering strategy is proposed to retard the water loss of GPE from the half‐open structured air cathode. In detail, the poly(ethylene vinyl acetate)/carbon powder (PEVA‐C) nanofiber composite interface layer with features of hydrophobicity, high conductivity, air permeability, and flexibility are prepared on the carbon cloth and set up between the GPE and electrode. The as‐assembled ZAB with simple alkaline PVA GPE exhibits an impressive cycle life of 230 h, which outperforms ZAB without the PEVA‐C nanofibers interface layer by 14 times. Additionally, the growth of Zn dendrites can be suppressed due to the tardy water loss of GPE.

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