Modular Fuel Cell Stacks Using 3D-Printed Resin-Based Frames

Abstract This study presents the design, fabrication, and performance evaluation of modular fuel cell stacks using 3D-printed resin-based frames, targeting portable and decentralized energy storage applications. The innovative design prioritizes low cost, mechanical robustness, and ease of component replacement, making it suitable for deployment in harsh environments such as agricultural settings. Unlike conventional graphite-based bipolar plates, the resin structures offer printability and modularity, enabling rapid prototyping and field-level maintenance. Electrochemical characterization of single cells and stacks demonstrated high reproducibility, with optimal current densities of 150–165 mA·cm–2 and peak power densities above 55 mW·cm–2 at 20 °C. Series and parallel configurations of up to five cells were tested, revealing that stack performance is highly sensitive to the quality of the membrane electrode assemblies (MEAs). Variability in MEA electrocatalytic properties led to significant differences in polarization resistance and power output, underscoring the importance of component uniformity. Series connections increased voltage, while parallel configurations enhanced current density, although both reached similar maximum power densities. Current densities at which the maximums are obtained are very different, being around 20–30 mA·cm–2 for the series connection and 80–100 mA·cm–2 for the parallel connection. The stack of 5 MEAs reached up to 6.05 W while the stack of 3 MEAs reached 4.15 W. Operational tests under realistic conditions (using air as the oxidant and hydrogen from pressurized canisters) confirmed the system’s robustness. During the test, the stack of three MEAs was sequentially supplied with the gas contained in five 1-L canisters pressurized at 4 bar and it maintained a stable 0.5 A output over 3.29 h, with a hydrogen utilization efficiency of 0.6 Wh·mg–1 H2. These results are obtained in the frame of a project about smart irrigation of crops and values obtained have validated the feasibility of 3D-printed fuel cell stacks for integration into these renewable energy systems, particularly for irrigation in water-scarce regions. Compared to conventional batteries, this approach offers a promising scalable, cost-effective, and field-serviceable alternative for sustainable energy storage.