Cationic-Backbone Ionic Polymer-based Robust and High Hydroxide Ion Transporting Membranes for Alkaline Solar-to-Hydrogen Generators

The Department of Energy seeks the development of anion exchange polymeric membranes for solar-to-hydrogen generators that operate in alkaline aqueous electrolytes for energy production and storage applications. These membranes must function in highly alkaline pH 14) electrolytes and have: 1) high hydroxide ion conductivity/transport; 2) high resistivity to separate anode and cathode electrically; 3) high chemical and mechanical stability; 4) superior ability to prevent crossover of hydrogen and oxygen gases; and 5) a commercially viable cost of manufacturing. During the proposed project, the company will develop a novel class of phenylated-pyridinium cationic-backbone ionic polymers with alkyl and/or fluorinated side-chains to achieve robust and high performance anion exchange polymeric membranes. Overall,theproposedcationic- backbone ionic polymer-based anion exchange polymeric membranes will improve anion hydroxide ion) transport/conductivity, mechanical and chemical stability and gas barrierproperties. In Phase I, the company will synthesize, characterize and prepare proposed ionic polymers and membranes and then study them extensively to evaluate their: 1) thin-film forming capability, 2) thermal and mechanical properties, 3) electrical resistance, 4) anion/hydroxide ion conductivity/transport, 5) gas permeability behavior preventing crossover of hydrogen and oxygen gases), 6) chemical stability in strongly alkaline aqueous electrolytes, and 7) operating temperature range. These results will be compared with a commercially available anion exchange polymeric membrane as the current standard for the solar-to-hydrogen generationand anion exchange polymeric fuel cell technologies. This effort will facilitate transitioning the technology to Phase II development. The phenylated-pyridinium cationic-backbone ionic polymer-based anion exchange membranes proposed for applications in solar-to-hydrogen generators and fuel cells for transportation applications to power zero emission vehicles can be adapted for use in next generation stationary power sources, houses, businesses, portable electronics, scientific exploration and military applications.