Silsesquioxane Composite Membrane for High-Temperature Fuel Cells

The patent employs composite materials by combining silsesquioxane cage structures with conductive polymers (such as polybenzimidazole) and phosphoric acid-based materials. This composite approach allows the membrane to simultaneously achieve high temperature stability from the silsesquioxane framework, proton conductivity from the phosphoric acid-doped conductive polymer, and mechanical durability from the synergistic interaction between components, thereby resolving the contradiction between temperature operation and reliability

The patent changes the chemical and physical parameters of the electrolyte membrane by introducing phosphoric acid doping into the silsesquoxane-conductive polymer composite. This parameter change (adding phosphoric acid) fundamentally alters the membrane's properties, enabling it to maintain high proton conductivity and structural stability at middle and high operating temperatures, thus improving reliability without sacrificing temperature capability

The patent creates a composite material system where silsesquioxane provides thermal stability through its rigid cage structure, while conductive polymers and phosphoric acid-based materials contribute mechanical flexibility and proton transfer pathways. The composite structure allows each component to compensate for the weaknesses of others, maintaining both thermal stability and mechanical/protonic functionality at high temperatures

The patent applies local quality by creating distinct functional regions within the membrane structure. The silsesquioxane cages provide localized thermal stability, while the phosphoric acid-doped conductive polymer regions provide localized proton conduction pathways. This spatial differentiation of functions allows the membrane to simultaneously exhibit high thermal stability in certain regions and excellent proton transfer ability in other regions