Visarn Lilavivat

Novel Current Distribution Board for PEM Devices

Distribution Board is only 1.5mΩ for a 50cm 2 cell. The printed board circuit designed consists of a Kapton base layer, copper deposit, nickel deposit, and gold flash to prevent oxidation. The design is based on a tripleserpentine flow field plate such that a negligible amount of material interferes with the flow channels. The only material that interferes with the flow field is that of thin copper strips that run perpendicular to the flow pattern. This small amount of material is added to prevent overheating from occuring. The Current Distribution Board consists of 10 individual current collecting areas that match the triple serpentine flow field separated by thin sections of Kapton from the base layer. Adaptors are attached to both sides of the board which collect the current through 12 AWG wires threaded thru hall-effect sensors. By using somewhat thick wires in the adaptors, the external resistances are minimized such that an internal resistance from an MEA will be detected. The hall-effect sensors output an analog signal that is proportional to the amount of current detected. This analog signal is routed to a Data Acquisition Board which is connected to a computer in order to collect and record data. During use, the Current Distribution Board is separated from the MEA by a Gas Diffusion Layer (GDL) which contains continuous conductive fibers. This means some of the current will smear throughout the 10 individual current collecting areas thus giving a false current reading. However, this is effect is compensated for by applying a set of mathematical equations for each of the sections in order to collect and record the true current. Additionally, a mathematical model is being developed based on experimental results. This model will help determine the fuel cell’s performance based on different testing conditions but ultimately be used as a tool for water management of the cell. Acknowledgement