SBIR Phase I: Ultrathin Polymer Electrolyte Composites with Exceptional Conductivity, Mechanical Strength and Chemical Durability

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) project is to produce polymer composites that enable commercialization of alkaline electrochemical devices, such fuel cells and electrolyzers. The use of fuel cell technologies will help preserve the environment, mitigate climate change, decreasing our carbon footprint and securing renewable energy supply. Electrolyzers are an increasingly attractive method of producing ultrapure hydrogen, an essential chemical feedstock and fuel. Currently, widespread adoption of these technologies is prevented by the high system costs, which are driven by the platinum catalysts. Operating under alkaline conditions with alkaline exchange membranes (AEMs) is necessary to relieve this pain point by allowing the use non-precious metal catalysts (e.g. stainless steel, nickel, cobalt, and their alloys). Moreover, AEMs will be less expensive to produce and recyclable at the end of lifetime, unlike the existing polymer electrolytes, further decreasing the cost of devices. Producing commercially viable AEMs enables the widespread deployment of fuel cell and electrolyzer systems by making the technology economically competitive with incumbent fossil fuel based energy sources. This SBIR Phase I project proposes to produce polymer electrolyte composites that meet the stringent performance criteria for a commercially viable AEM, including durability, hydroxide conductivity and mechanical strength under alkaline operating conditions. A proprietary polymer composition with unprecedented chemical stability will be incorporated into microporous polymer structural supports. Typically, cation percentage in AEMs must be kept low, otherwise the membranes swell excessively and deteriorate during operation. Incorporating polymers into structural supports permits increased cation concentration and ion exchange capacity (IEC), resulting in AEMs with high hydroxide conductivity. Furthermore, the mechanical strength of the composite is determined by the support and is not reduced by high IEC, like unsupported membranes. A polymerization method will be employed that allows fine control over cation concentration and the reaction can be conducted inside the support, simplifying composite fabrication. The combination of our unique polymer composition and a structural support that maximizes conductivity without losing mechanical strength, is a crucial milestone for the commercialization of our technology.