Bipolar plates for the next generation of proton exchange membrane fuel cells (PEMFCs): A review of the latest processing methods for unconventional flow channels

Abstract

The rapid, unsustainable depletion of finite fossil fuel resources and their environmental consequences demand the deployment of affordable clean and sustainable energy solutions. Polymer electrolyte membrane fuel cell (PEMFC) technology is an important pathway in decarbonization of modern energy systems, especially when fueled by high-purity green hydrogen. In PEMFCs, bipolar plates largely determine cell efficiency, longevity, and affordability, which in turn depends on both material selection and design of the embedded flow channels. Conventional manufacturing processes have long been used to fabricate standard bipolar plate designs; however, they are incompatible with unconventional, intricate geometries due to their insufficient resolution and precision in fabrication of fine features, and reliance on multi-step post-processing modifications that limit their design adaptability. This lack of design flexibility impedes the translation of innovative laboratory-scale concepts to industrial-scale production and their practical adoption. In recent years, a growing body of research publications and patent disclosures has reported advanced manufacturing methods, such as additive manufacturing, capable of producing intricate bipolar plate geometries at competitive costs. However, a discussion of these manufacturing approaches, along with an assessment of their scalability and industrial readiness, remains absent in the literature. This study aims to fill this gap. It outlines recent progress and proposes future research directions toward affordable and efficient bipolar plate solutions for advanced PEMFC systems.

Figures (10)

• Figure 1: Schematic representation of a typical PEMFC stack and its operation principle. The upper illustration depicts the electrochemical processes where hydrogen at the anode loses electrons and oxygen at the cathode accepts electrons and protons to complete the reaction. The section shows a detailed cross-sectional view of the MEA and BP, morphology and characteristic thickness of each constituent layer. Data adapted with permission from kazemi2026topology.
• Figure 2: Progression of stack-level volumetric power density (including end plates) in Toyota and Honda FCEVs. The trend highlights how thinner bipolar plates and improved flow-field architectures have enabled more compact, high-performance fuel cell stacks over time jiao2021designingkonno2015developmentsaito2009newinoue2005nextkikuchi2016development.
• Figure 3: Examples of porous BP structures: (a) three-dimensional mesh BP adopted in the first generation Toyota Mirai, reproduced with permission from zhang2022porousbao2019analysis; (b) three-dimensional mesh with non-uniform arrangement of baffles, adapted with permission from choi2022experimental; (c) representative fine mesh, wire mesh, and tetrakaidecahedron structures with localized enlargement and associated structural parameters, reproduced with permission from sun2024effects; (d) Scanning electron microscopy (SEM) images of foam plates fabricated from Ni, graphene, and copper, reproduced with permission from shin2018effectpark2019gaspark2019achievingsun2025porous; and (e) porous BP used in the Hyundai NEXO, reproduced with permission from zhang2022porous.
• Figure 4: Examples of BPs with unconventional, non-intuitive flow patterns: (a) non-interdigitated, leaf-inspired configuration with constant channel width and interdigitated design with spatially varying channel widths determined by Murray’s law, adapted with permission from guo2014bio; (b) gas channel layouts inspired by ginkgo leaf venation and net leaf patterns, reproduced with permission from kang2019performance; (c) channel geometries obtained via reduced-order two-dimensional optimization to maximize output power and current density homogeneity over the current collector, reproduced with permission from behrou2019topology; (d) flow geometries optimized to maximize mean current density while minimizing flow resistance for different inlet-outlet configurations, reproduced with permission from xia2024topology; and (e) optimized layouts derived from three-dimensional and simplified two-dimensional topology optimization, formulated to maximize reactant concentration at the catalyst layer at low power dissipation, reproduced with permission from kazemi2026topology.
• Figure 5: Comparative overview of additive manufacturing processes applicable to PEMFC production, with emphasis on technological readiness and application-specific limitations taylor2007inkjetzubkova2026advancedpiri20203dhusaini2019digitalmunoz2023engineeringniblett2022utilizationjang2022effectsyang2019novelmadheswaran2024mwcntmadheswaran2025pemfc.