A reinforced composite membrane of two-layered asymmetric structure with Nafion ionomer and polyethylene substrate for improving proton exchange membrane fuel cell performance

•PE-based reinforced membrane shows a competitive performance reaching PEMFC with Nafion XL.•Annealing at 150 °C improves the mechanical property and ion conductivity.•Interfacial resistance between Nafion and PE is a major factor of performance reduction.•Immiscibility of Nafion and PE accelerates performance degradation in low humidity conditions.