Bioinspired supramolecular macrocycle hybrid membranes with enhanced proton conductivity

Abstract Enhancing the proton conductivity of exchange membranes (PEMs) is essential to expand applications membrane fuel cells (PEMFCs). Inspired by conduction mechanism bacteriorhodopsin, cucurbit[ n ]urils (CB[ ], where number glycoluril units, = 6, 7, or 8) are introduced into sulfonated poly(ether ether ketone) (SPEEK) matrix fabricate hybrid PEMs, employing a nature-inspired chemical engineering (NICE) methodology. The carbonyl groups CB[ ] act as proton-conducting sites, while host–guest interaction between and water molecules offers extra pathways. Additionally, molecular size aids in their dispersion within SPEEK matrix, effectively bridging unconnected sulfonic group domains membrane. Consequently, all exhibit significantly enhanced conductivity. Notably, incorporating 1 wt.% CB[8] (CB[8]/SPEEK-1%) demonstrates highest 198.0 mS·cm −1 at 60 °C 100% relative humidity (RH), which 228% greater than that pure under same conditions. Moreover, superior cell performance. CB[8]/SPEEK-1% achieves maximum power density 214 mW·cm −2 , representing 140% improvement over (89 ) 50 RH. These findings serve foundation for constructing continuous pathways utilizing supramolecular macrocycles electrolytes other applications.