Anion conducting poly(vinyl alcohol)/poly(diallyldimethylammonium chloride) membranes with high durable alkaline stability for polymer electrolyte membrane fuel cells

Novel and highly durable alkaline anion-exchange membranes, PVA/PDDA–OH−, are synthesized using a combined thermal and chemical cross-linking method. In the synthesis, poly(vinyl alcohol) (PVA) is used as polymer matrix and poly(diallyldimethylammonium chloride) (PDDA) as anion charge carriers. The resulting membrane exhibits a high hydroxide conductivity of 0.025 S cm−1 at a polymer composition PVA/PDDA being 1:0.5 by mass. A promising H2/O2 fuel cell peak power density of 32.7 mW cm−2 is reached for MEA fabricated with this PVA/PDDA–OH− at 25 °C. The membrane also shows a strong alkaline stability in 8 M KOH at 80 °C for 360 h. This is considered a new record for the fully cation-free hydrocarbon membranes for the use in alkaline fuel cell, seeing that PVA/PDDA–OH− is made simply of aliphatic skeletons.

► Anion conducting PVA/PDDA–OH− membranes are prepared. ► The membrane exhibits high OH− conductivity of 0.025 S cm−1 at 25 °C. ► The membrane shows a strong alkaline stability in 8 M KOH at 80 °C for 360 h. ► A H2/O2 fuel cell power density of 35.1 mW cm−2 is reached at 25 °C.