Flow-Channel Shape Design of Stamped Bipolar Plate for PEM Fuel Cell by Micro-Forming Simulation

PEM fuel cells are promising candidate as most environmentally friendly power source for transport and stationary cogeneration applications due to its high efficiency, high power density, fast startup and system robustness. But the PEM fuel cell is still too expensive for widespread commercialization. Bipolar plate is one of the most important and costliest components of PEM fuel cells and accounts to more than 80% of the weight and 30% of the total cost in a fuel cell stack. To reduce the cost and weight of fuel cell stacks and at the same time meeting several technical requirements for mass production, a prototype of low-cost stamped bipolar plates made of stainless steel 316 sheets has been introduced in this paper. Base on micro sheet forming process simulation experiments, the influence of some key dimensions of the flow channel to the formability of the stamped polar plate is also detailedly studied. Micro-forming simulation results show that relative punch radius r/t (punch radius r, sheet thickness t) and the ration of the width of coolant channel to channel depth w/h (width of coolant channel w, channel depth h) are import factors that decide the final formability of the whole polar plate. Large r/t is recommended for compact flow channel design and larger w/t is recommended for safer forming process.