3D printed electrodes for bubble management in high-rate water electrolysis

Abstract High-rate water electrolysis (> 400 mA·cm−2) is pivotal for scalable green hydrogen production, yet the intense gas evolution within three-dimensional (3D) electrodes limits both electrolysis efficiency and long-term stability. This review examines how 3D printing revolutionizes electrode design to optimize bubble management. The techniques, such as direct ink writing (DIW), vat photopolymerization (VP), and selective laser melting (SLM), enable the fabrication of complicated electrode architectures which surpass conventional 3D electrodes with stochastic pores. We classify the designs into two families, including periodic ordered structures and functionally graded and directional architectures. By integrating operando high-speed imaging with multiphysics simulation, recent studies reveal how macroscopic topology, pore geometry, and nanoscale morphological engineering synergistically reduce the three-phase contact length, accelerate bubble detachment, and lower the mass transport resistance while balancing electrochemical surface area. Despite being an emerging area, architected 3D printed electrodes offer a promising approach to breakthrough in high-rate water electrolysis. In light of recent reports, we also identify the key challenges and present an outlook on interdisciplinary research of 3D printing and bubble management at the end of this review, with the aim that this review serves as a helpful reference for the continued development of the field.