Advancing electrolyzer design through additive manufacturing: A review on 3D printing in hydrogen electrolysis

Hydrogen production via water electrolysis plays a central role in advancing sustainable energy systems but is hindered by conventional fabrication methods that restrict component complexity, scalability, and cost efficiency. This review connects additive manufacturing (AM) techniques to the performance, durability, and economic requirements of electrolyzer components, aiming to identify gaps and outline future directions for deployment. AM applications are systematically examined at the component level, including electrodes, membranes/separators, flow plates, and integrated stacks, and then compared across 5 a.m. routes across resolution, material and equipment cost, build speed, design freedom, and electrochemical performance. Printable materials (conductive polymers, metals, ceramics, and catalyst/coating-based functional materials) are benchmarked for printability, electrical conductivity, mechanical robustness, thermal stability, catalytic activity, and cost. The analysis in this review shows that Stereolithography(SLA)/Digital Light Processing (DLP) offers the highest resolution and design flexibility; Fused Deposition Modeling (FDM) and Direct Ink Writing (DIW) provide cost‐effective alternatives; and Powder Bed Fusion (PBF) and hybrid approaches balance these tradeoffs. Material benchmarking highlights that polymers excel in printability and cost‐effectiveness, metals in conductivity and mechanical strength, and ceramics in thermal stability and catalytic activity. Key results include up to 27 % faster hydrogen evolution rates for printed electrodes and up to 57 % higher power density in structured flow plates. Moreover, AM significantly reduces material waste and simplifies assembly, delivering economic and environmental benefits. The remaining challenges include achieving material homogeneity, ensuring long‐term corrosion resistance, maintaining mechanical integrity, and establishing standardized evaluation protocols. Future research should focus on multi‐material integration, topology‐optimized geometries, integrated in situ functionalization methods, and robust lifecycle management frameworks to accelerate commercial deployment of AM‐based electrolyzer technologies.