Thermal-shock-processed thin proton exchange membranes for efficient and durable water electrolysis with reduced hydrogen crossover

This work presents a Joule-heating strategy to create thin proton exchange membranes (PEMs) with high proton conductivity and low H₂ crossover. The treated PEMs assembled electrolyzer achieves a record current density of 3.72 A cm^-2 at 1.9 V with 1250 h durability at 2 A cm^-2 for water electrolysis.