A review of high-consistency assembly and sealing structures for hydrogen fuel cell stacks

Xueming Gao, Jingsong Tan, Xiaobo Huang, Shuanglong Xu

Proton exchange membrane fuel cell (PEMFC) stacks require the precise assembly of hundreds of individual cells to achieve practical power output, making high-consistency assembly and reliable sealing critical determinants of electrochemical performance, operational safety, and long-term durability. This review examines the mechanical foundations of stack assembly, emphasizing the pivotal role of clamping force magnitude and contact pressure uniformity across the active area. It systematically analyzes sealing structures, including PEM-wrapped, MEA-wrapped, rigid frame, and direct-compression configurations, alongside gasket materials such as silicone rubber, EPDM, and fluoroelastomers, evaluating their chemical stability, compression set, and degradation mechanisms under acidic and thermal cycling conditions. Furthermore, the review explores the multiphysics coupling between assembly mechanics and sealing performance, addressing manufacturing tolerance propagation, bipolar plate misalignment, thermal-mechanical deformation, and the influence of bolt torque patterns on gas tightness. Intelligent optimization methodologies, including surrogate modeling and multi-objective genetic algorithms, are discussed as enabling tools for enhancing pressure uniformity in large-scale stacks. Finally, future research directions are identified, encompassing in-situ sensing technologies, nanocomposite gasket development, and digital twin frameworks for predictive maintenance, thereby providing a comprehensive reference for advancing the manufacturing reliability of next-generation hydrogen fuel cell systems.