Economical High Performance Thermoplastic Composite Bipolar Plates

79274 Current fuel cell bipolar plate technology requires costly, time consuming fabrication steps that result in a high cost per unit energy. Typically, metallic-based materials are used, which are heavy and limited by corrosion and chemical resistance, and graphite-based materials, which are limited by mechanical strength and structural integrity. Composite materials have been recently investigated as a potential bipolar plate platform, but current technology is limited by two fabrication processes: (1) an expensive chemical vapor infusion process, and (2) a slow, expensive machining process to generate flow channels. This project will develop novel thermoplastic composite materials, along with a manufacturing process, produce composite material sheets that can be compression molded into high performance, mechanically robust bipolar plates. The resulting plates will be lightweight for reduced vehicle payload, have high mechanical strength for structural durability, and offer high electrical conductivity in both the in-plane and through-plane directions. The manufacturing process will eliminate the need for chemical vapor infusion and flow channel machining, resulting in a significantly reduced cost over current technology. Phase I will produce wet-lay composite sheets containing varied conductive filler loading levels, which will be compression molded and/or stamped to form bipolar plates with high in-plane and through-plane conductivities, mechanical properties, and appropriate physical properties. The structure and processability of wet-lay sheets, the molding and/or stamping conditions, and the properties of bipolar plates and their relationships will be investigated to develop a continuous manufacturing model for cost analysis. Commercial Applications and Other Benefits as described by the awardee: High performance fuel cell bipolar plates are primarily targeted for automobile use, but it is likely that fuel-cells will first find applications in businesses and homes before use is widespread in transportation. The high-reliability power market, for digital data centers, hospitals, etc., by itself is estimated at $10 Billion. Additionally, there is a big demand for longer lasting power sources for portable equipment such as laptops, PDAs, cell phones, etc. Fuel cells would be an ideal candidate as they are expected to last 10 times longer than conventional rechargeable batteries. However, to make fuel cells truly competitive, the cost of bipolar plates needs to be significantly reduced.