Mineral nanofibre reinforced composite polymer electrolyte membranes with enhanced water retention capability in PEM fuel cells

► For the first time palygorskite with unique nanochannels was composited with Nafion. ► Both water retention capability and mechanical property of the composite membrane was significantly enhanced. ► Proton conductivity of the composite membrane increased by 75% more than pristine Nafion membrane at 0% RH. ► Much more stable in dimensional changes and a great improvement upon a mechanical property were observed. ► Palygorskite offers a promising strategy to reinforce and hydrate Nafion membranes under harsh working condition for PEMFCs.