Revealing the Underlying Mechanisms in Performance Enhancement of Shellular Lattice Electrodes During Anion Exchange...

Anion exchange membrane water electrolysis (AEMWE) is widely considered as a pragmatic approach for next-generation hydrogen production. The constraints on its efficiency mostly arise from the traditional gas diffusion layer (GDL), which is made of a random open-cell structure that traps bubbles within its porous matrix. Utilizing micro laser powder bed fusion 3D printing technology, we designed and fabricated regular open-cell continuous shellular lattice GDLs that manage the gas-liquid flow. Precision-controlled Gyroid lattice achieves advanced-catalyst-level overpotentials, a more-than-twofold increase in charge-transfer capacity, and electrochemical stability over 640 h. Despite Fischer-Koch S structure offering the highest real surface area factors, the Gyroid structure outperforms other lattices due to enhanced bubble escape phenomenon and convective replenishment of reactants. Multifactor parametric analysis reveals that mass-transfer factors dominate over real-surface-area factors in performance enhancement, as they can minimize bubble retention and expand active site accessibility, thereby suppressing overpotential. The continuous shell geometry also provides uninterrupted electron pathways and hydrophilic surface control, reducing gas entrapment compared to commercial GDLs. These findings suggest that the architected thin-walled nickel shellular lattices are superior diffusion layer structure designs for AEMWE, which highlight the synergy of mass-transfer and surface-exposure as a general strategy for electrolysis cell component design.