CC BY 4.0Tsehaye, Misgina TilahunMisgina TilahunTsehayeGebreslassie, Getachew TeklayGetachew TeklayGebreslassieChoi, Nak HeonNak HeonChoiMilian, DiegoDiegoMilianMartin, VincentVincentMartinFischer, PeterPeterFischerTübke, JensJensTübkeKissi, Nadia ElNadia ElKissiDonten, Mateusz L.Mateusz L.DontenAlloin, FannieFannieAlloinIojoiu, CristinaCristinaIojoiu2022-03-0617.11.20212021https://publica.fraunhofer.de/handle/publica/27011310.3390/molecules26134062The membrane is a crucial component of Zn slurry-air flow battery since it provides ionic conductivity between the electrodes while avoiding the mixing of the two compartments. Herein, six commercial membranes (CellophaneTM 350PØØ, Zirfon®, Fumatech® PBI, Celgard® 3501, 3401 and 5550) were first characterized in terms of electrolyte uptake, ion conductivity and zincate ion crossover, and tested in Zn slurry-air flow battery. The peak power density of the battery employing the membranes was found to depend on the in-situ cell resistance. Among them, the cell using Celgard® 3501 membrane, with in-situ area resistance of 2 O cm2 at room temperature displayed the highest peak power density (90 mW cm−2). However, due to the porous nature of most of these membranes, a significant crossover of zincate ions was observed. To address this issue, an ion-selective ionomer containing modified poly(phenylene oxide) (PPO) and N-spirocyclic quaternary ammonium monomer was coated on a Celgard® 3501 membrane and crosslinked via UV irradiation (PPO-3.45 + 3501). Moreover, commercial FAA-3 solutions (FAA, Fumatech) were coated for comparison purpose. The successful impregnation of the membrane with the anion-exchange polymers was confirmed by SEM, FTIR and Hg porosimetry. The PPO-3.45 + 3501 membrane exhibited 18 times lower zincate ions crossover compared to that of the pristine membrane (5.2 × 10−13 vs. 9.2 × 10-12 m2 s−1). With low zincate ions crossover and a peak power density of 66 mW cm−2, the prepared membrane is a suitable candidate for rechargeable Zn slurry-air flow batteries.enChemical Sciencesmaterial chemistrymembrane coatingpower densityUV irradiationZinc slurry-air flow batteryZincate crossover660547journal article