Fuel cells with an operational range of –20 °C to 200 °C enabled by phosphoric acid-doped intrinsically ultramicroporous membranes

Conventional proton exchange membrane fuel cells (PEMFCs) operate within narrow temperature ranges. Typically, they are run at either 80‒90 °C using fully humidified perfluorosulfonic acid membranes, or 140‒180 non-humidified phosphoric (PA)-doped to avoid water condensation-induced PA leaching. However, the ability function over a broader range of and humidity could simplify heat management, thus reducing costs. Here we present PA-doped intrinsically ultramicroporous membranes constructed from rigid, high free volume, Tröger’s base-derived polymers, which allow operation −20 200 °C. Membranes with an average ultramicropore radius 3.3 Å show syphoning effect that allows retention even under highly conditions more than three orders magnitude higher conductivity conventional dense polybenzimidazole membranes. The resulting PEMFCs display 95% peak power density after 150 start-up/shut-down cycles 15 can accomplish 100 cycles, Most designed few tens degrees, but functioning in be advantageous. authors use ultramicroporous, acid-doped cell