The performance of a novel pseudo-bipolar bi-cell piezoelectric proton exchange membrane fuel cell with a smaller nozzle and diffuser

Previous studies of a bi-cell piezoelectric proton exchange membrane fuel cell with a nozzle and diffuser (PZT-PEMFC-ND bi-cell), using a novel pseudo-bipolar design, have shown that the performance of the bi-cell could be 1.6 times greater than that of the single cell. In this study, this novel design, using a reduced nozzle and diffuser, contains two cells with two outside anodes and two inside cathodes that share a common PZT vibrating device for pumping air flow. The results show that the bi-cell should be operated with a larger stoichiometric ratio of 1.5 and a cell temperature of 50 °C to prevent concentration loss. Furthermore, the performance of the bi-cell using one degraded membrane electrode assembly (MEA) and one normal MEA is investigated to understand the current flow characteristic of the bi-cell. Although an internal current is observed, the bi-cell can still deliver a non-negative power. This finding will help reinforce the viability of using a PZT-PEMFC-ND bi-cell for future stack designs. Moreover, the power consumption of the PZT device is temperature-dependant and this should be taken into consideration when determining the net power of the PZT-PEMFC-ND bi-cell. The maximum net power of the bi-cell is found to be 0.7 W.