Crosslinked electrolyte networks with enhanced ionic transport and stability for alkaline fuel cells

Crosslinked electrolyte networks were developed and systematically investigated as membranes for alkaline fuel cells. The networks were constructed through direct backbone crosslinking followed by quaternization with N-heterocycle ammonium groups, forming ion-conducting pathways with improved structural stability. The optimized membrane exhibited a hydroxide ion conductivity of 118.21 mS cm⁻¹ at 80 °C and retained conductivity with only minor loss after 4 weeks in 5 M NaOH at 80 °C. Molecular dynamics simulations provided qualitative insight into ion and water transport within the crosslinked framework, consistent with the experimental conductivity trends. Electrochemical testing in H₂/Air single cells demonstrated a peak power density of 81.74 mW cm⁻² at 239.7 mA cm⁻² and 80 °C, serving as an initial demonstration of the membrane's feasibility in fuel cell operation. This study presents a straightforward strategy for constructing crosslinked electrolyte networks with balanced ionic conductivity, durability, and mechanical strength, providing a basis for future optimization in alkaline fuel cell applications.