Development of a PEFC with serpentine hybrid pattern gas channels (1st report, design and performance of the PEFC)

We have developed hybrid pattern gas channel consisting of high and low pressure gas channels for polymer electrolyte fuel cells (PEFCs). The pressure difference between them gives rise to in-plane flow in the gas diffusion layer (GDL) under the rib. This hybrid pattern gas channel allows to configure both parallel and serpentine gas channels for the high pressure channels. The low pressure channel is a serpentine gas channel to improve water exhaust ability by its large flow velocity. By taking advantage of the hybrid pattern gas channels, stability of the cell voltage is improved by increase in the flow velocity of the high pressure gas channel when it is switched to the serpentine gas channel. Moreover, atmospheric air introduced into the low pressure gas channel without humidification can dry and exhaust product water extruded to the GDL under the low pressure gas channel. However, flow rate of this air should be optimized to avoid output voltage drop due to the drying of the membrane electrode assembly.