O₂ selective membranes based on a dextrin-nanosponge (NS) in a PVDF-HFP polymer matrix for Li-air cells

A novel oxygen selective highly hydrophobic membrane is prepared by non-solvent induced phase separation in which a dextrin-based nanosponge is incorporated into a poly(vinylidene fluoride co-hexafluoropropylene) (PVDF-HFP) matrix. The membrane presents high capability to entrap moisture from air as well as good hydrophobic behaviour. The membrane was assembled in a pouch type Li-air cell, which was cycled in a galvanostatic mode at curtailed capacity, in air with 17% relative humidity (RH). Owing to the protection of the membrane, the Li-air cell was able to discharge and re-charge for approximately 145 cycles, which correspond to about 1450 h of cell operation.