Low-cost high-volume durable coating method for bipolar plates

C56-18j-273158One of the main challenges to the large-scale commercialization of Proton Exchange Membrane Fuel Cells for high power applications is the faster protective coating of the component bipolar plates. Applications such as large trucks, buses, and marine vehicles require long term durability. The bipolar plates need to be corrosion resistant under thermal cycling over the fuel cell lifetime. Therefore, for bipolar plate protective coating, innovations in materials and coating methods are required. Various methods have been used for coating purposes, such as spray coating, Physical Vapor Deposition, Chemical Vapor Deposition, and magnetron sputtering. In several of these methods, the operating temperatures are over 600 °C, which could cause deterioration of the metal bipolar plates. These traditional coating methods also suffer from lower deposition rates. While Plasma Enhanced Chemical Vapor Deposition method provides a way to coat bipolar plates faster at temperatures below 600 °C, the deposition rates need to be further increased. To address this challenge, we propose to develop a novel Plasma-Assisted Chemical Vapor Deposition method for quality coatings on Bipolar Plates with faster deposition rate, by developing a novel megahertz rate nanosecond burst power supply to generate more intense plasma efficiently. The coating material will be carbon-based which is cost -effective for large scale implementation. The electric circuit of the power supply is designed to dump all the input energy into the plasma rather than dissipation in current limiting resistances and can be operated in a pulsed mode. This will enable multilayer amorphous carbon- titanium carbide composite coatings fabricated at a faster rate to achieve the Department of Energy’s near-term manufacturing target of 20,000 stacks/year at a production scale target system cost of $80/kW. The Phase I project efforts will involve development and demonstration of the proposed plasma coating technology of burst mode megahertz nanosecond discharge. Experiments will be conducted characterizing durability, interfacial electrical resistance, and stability with thermal cycling in acidic environments. The coated bipolar plates will be tested in a fuel cell stack. Preliminary Techno-Economic and Life Cycle Analysis for scaling, and implementation, will be conducted. Phase II of the project will study more detailed plasma coating recipes including variations in morphology of multi-layers, material composition, pressure, temperature, and coating layer thickness, along with detailed techno-economic and lifecycle analyses. The development of such innovative high deposition rate and efficient technology will have many applications in other fields of micro electro-mechanical systems, solar array fabrication, protective coatings, flexible electronics, quantum computing and biomedical.