Experimental study on the effect of flow channel parameters on the durability of PEMFC stack and analysis of hydrogen crossover mechanism. (1st February 2023)

• Record Type: Journal Article
• Authors: Chu, Tiankuo; Tang, Qianwen; Wang, Qinpu; Wang, Yanbo; Du, Hong; Guo, YuQing; Li, Bing; Yang, Daijun; Ming, Pingwen; Zhang, Cunman
• Is Part Of: Energy. Volume 264(2023)
• Publication Date: 2023-02-01
• Subjects: Polymer electrolyte membrane fuel cell -- Flow field depth -- Hydrogen crossover -- Membrane degradation -- Free radical attack; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Energy consumption -- Periodicals; 333.7905
• DOI: 10.1016/j.energy.2022.126286
• Languages: English
• ISSNs: 0360-5442

Abstract

Abstract: Polymer electrolyte membrane fuel cell (PEMFC) is a leading technology with a bright future in the field of transportation. The bipolar plate structure has a profound impact on the mass and heat transfer of PEMFC. In this study, the durability tests of two stacks with different channel depths are carried out for 1000 h respectively on the 1 kW fuel cell stack test platform. We detect the overall performance change of the stack and characterize the membrane electrode assembly at the end of the test. Based on the first principle calculation, the mechanism of membrane degradation and hydrogen crossover is analyzed, and some durability experimental results are explained. The results show that the durability of the PEMFC with a shallow flow channel is worse, the voltage drops significantly, and the hydrogen crossover increases significantly after 500 h. The first principle calculation results reveal that the chemical structure change of the membrane is caused by the free radical attack. Hydrogen crossover promotes ∙ H to attack carbon-fluorine bonds. This paper reveals the mechanism of hydrogen crossover and its influence on the catalyst layer, which is helpful to improve the durability of PEMFC. Highlights: Shallow channel are prone to hydrogen crossover and poor durability of PEMFC. Hot spots accelerates the PEM degradation and increases hydrogen crossover. The chemical structure of membrane changes with the generation of bubbles. The ∙ H radical is easy to destroy the carbon-fluorine bond.