Development of a novel pseudo bipolar piezoelectric proton exchange membrane fuel cell with nozzle and diffuser

Previous studies of a piezoelectric proton exchange membrane fuel cell with nozzle and diffuser (PZT-PEMFC-ND) have shown that a PZT device could solve the cathode flooding problems and improve cell performance. In this study, an innovative design for a PZT-PEMFC-ND bi-cell with pseudo bipolar electrodes is developed to achieve a higher power in the stack design to solve water-flooding problems and improve cell performance. This new design, with a reaction area of 8 cm2, contains two cells with two outside anodes and two inside cathodes that share a common PZT vibrating device for pumping air flow. The influence of the varying aspect ratio (AR) of the diffuser elements on the unit cell-flow rate is investigated using a three-dimensional transitional model. The simulation results show that a proper AR value of 11.25 for the diffuser, with a smaller diffuser angle of 5°, could ensure a smoother intake of the air and, thus, better cell performance. The experimental results show that the performance of the PZT-PEMFC-ND bi-cell can be 1.6 times greater than that of the single cell.

Research highlights▶ In this study, an innovative design for a PZT-PEMFC-ND bi-cell with pseudo bipolar electrodes is developed to achieve a higher power in the stack design to solve water-flooding problems and improve cell performance. This innovative design, with a reaction area of 8 cm2, contains two cells with two outside anodes and two inside cathodes that share a common PZT vibrating device for pumping air flow. ▶ The PZT vibration frequency and cell temperature are the important operating parameters for increasing the performance of the PZT-PEMFC-ND module. The optimal PZT vibration frequency is f = 180 Hz at a temperature of 40 °C. And, the optimal geometry parameters are AR at 11.25 under θ = 5°. ▶ The PZT-PEMFC-ND bi-cell generates 1 W at T = 40 °C, f = 180 Hz, AR = 11.25, and θ = 5°. When compared with the single cell, the performance of the PZT-PEMFC-ND bi-cell was 1.6 times greater. The net power output of the bi-cell is about 0.8 W, due to the power consumption of 0.2 W for the PZT device at 180 Hz.