Study on hydrocarbon based polymer electrolyte membranes for polymer electrolyte membrane water electrolysis application

Abstract

Polymer electrolyte membrane water electrolysis (PEMWE) splits water into hydrogen and oxygen through electrochemical processes. In PEMWE, the membrane, crucial for separating gaseous reaction products and transporting protons, must exhibit excellent stability, strength, thermal resistance, proton conductivity, and gas crossover resistance. Despite being vulnerable to long-term performance issues, the membrane's degradation is primarily linked to contamination or chemical breakdown. This thesis explores the correlation between structural and physicochemical properties of sulfonated hydrocarbon-based polymer electrolyte membranes (PEM) in PEMWE. Divided into three chapters, Chapter 1 introduces PEMWE, PEM, and related research. Chapter 2 delves into the physicochemical properties and chemical durability of PEM, aiming to enhance stability by introducing a thioether linkage. Confirming the transition of the linkage in the water electrolysis environment, it was found to impact PEM's chemical stability. Chapter 3 proposes a multi-block copolymer synthesis with hydrophilic-hydrophobic nanophase separation, aiming to improve ion transport and mechanical properties. Consequently, the multi-block copolymer membrane outperforms commercial membranes.