Effect of pressure on through-plane proton conductivity of polymer electrolyte membranes

► An improved 2-electrode cell is developed for through-plane EIS analyses. ► The cell is designed to reproduce the actual suppressing pressure to a membrane. ► Significant thickness changes of the membrane under a pressure are defined. ► An electrochemical EIS analogy is presented based on the equivalent circuit model. ► Through-plane proton conductivity of a polymer electrolyte membrane is analyzed.