Design of Metallic Bipolar Plate and Stack for Air-breathing PEMFC

Abstract

This study aims to develop a metallic bipolar plate for proton exchange membrane fuel cell The DYNAFORM and LS-DYNA softwares are used to simulate the stamping process for metallic bipolar plates The optimal flow channel geometry and stamping coefficients are obtained by analyzing forming limit diagram thinning ratio and springback of the metallic bipolar plates A 5-cell air-breathing PEMFC with the metallic bipolar plates is as well assembled and tested Via the polarization curve and electrochemical impedance spectroscopy the performance and practicability of the metallic bipolar plates are verified A 5-cell air-breathing PEMFC with stamped SS316L bipolar plates of 334×72 65 mm2 is successfully developed in this work The maximum power density 131 73 mW/cm2 is obtained with forced air convection at an operating temperature of 45℃ a torque of 30 kgf-cm and a relative humidity of 100% If the back pressure is applied to the anode side of the PEMFC the power density is dramatically promoted to 253 03 mW/cm2 which is about 92% higher than that without back pressure As for the fabrication process of metallic bipolar plates the simulation results show that the optimal stamping parameters of SS316L plates are the binder force of 1500 kN the stamping speed of 250 mm/s the punch and die radiuses of 0 2 mm the blank thickness of 0 2mm and the flow channel depth of 0 65 mm Furthermore the binder force can reduce the springback effectively but the blank cracks as the force excesses 1500 kN Both the thinning rate and springback increase with increasing the channel depth With enlarging the punch and die radiuses properly the blank becomes safer and has smaller springback Additionally experiments are conducted to validate the dimension accuracy of numerical methods

Date of Award	2020
Original language	English
Supervisor	Chen-Yuan Wang (Supervisor)