New High Performance Water Vapor Membranes to Improve Fuel Cell Balance of Plant Efficiency and Lower Costs

Durability and cost have been identified as the 2 main needed improvement opportunities for vibrant commercialization of fuel cell vehicles by the DOE sponsored US Drive Fuel Cell Technical Team, with the humidifier and PEM membrane performance and cost being among the key concerns. During Phase II, Tetramer Technologies has developed new water vapor transport (WVT) membranes which significantly outperformed the current perfluorosulfonic acid (PFSA-Nafion) and other WVT membrane competitors at ~50% lower projected cost. Optimization of this new technology during Phase IIB, which will involve improved block copolymers, support structures, and IEC improvements will positively affect the fuel cell balance of plant efficiency and lower costs. These new polymer structures also showed no detrimental anhydride formation at the higher (120oC) cathode inlet temperatures required by fuel cell OEMs. This anhydride formation of conventional PSFA membranes has caused >60% reduction of water vapor performance at 85oC cathode inlet temperatures, and at the much higher required stack temperatures anhydride formation will only accelerate. Engineering an automotive fuel cell system to compensate for such significant losses would be complicated and expensive (in addition to the high cost of the PFSA WVT polymer), since a larger humidifier would have to be built to compensate for this WVT variation. This variation could also affect the durability and cost of the proton exchange membrane (PEM) stack. In addition to the power optimization, lower cost, and lower weight impacts afforded by a WVT system for fuel cell vehicles, these membranes are excellent enthalpy candidates for the high potential energy savings (~ 40%) achieved by conditioning air for the large HVAC market which currently uses billions of btus. The primary focus of the proposed Phase IIB research will be to take advantage of the new technologies discovered during the delayed Phase II development to increase the commercial value proposition by further lowering manufacturing cost, optimizing polymer molecular architecture, extending durability, and performance (which will further decrease fuel cell engine cost, durability, and weight). Additionally, the Phase IIB research will include building of a commercial prototype humidification system by Dana Corporation (headquartered in Maumee, Ohio), which had worldwide sales of $6.6 billion in drive train components to the auto industry in 2014. The Phase IIB durability target will be 10% performance loss over a 500 hour accelerated test and 5000 hours over the operating life of the vehicle. We have strong support letters from Dana, GM, MTR, and Fumatech, providing significant in-kind product device testing and development cost with a goal of providing a prototype cathode humidifier for commercial vehicles and HVAC systems by 2018. By 2022, an estimated 120,000 m2 of membrane will be needed from Tetramer.