POS6-0500
Directional Gas Evacuation through Out-of-Plane Gas Pathways for Enhanced Mass Transport in Water Electrolyzers
When and Where
Nov 30, -0001
12:00am - 12:00am
Presenter(s)
Seunghyun Lee (Ulsan National Institute of Science and Technology)
Co-Author(s)
Abstract
While conventional water electrolysis research has predominantly focused on the development of novel electrocatalysts and membranes, resolving mass transport limitations within porous transport layers (PTLs) remains a critical hurdle for sustaining high-current, high-efficiency operation. Conventional hydrophilic PTLs inherently suffer from severe gas bubble trapping, which blocks catalysts active sites and impedes continuous electrolyte supply, ultimately inducing significant mass transport overpotential at high current densities.
To address this limitation from a surface wetting perspective, we introduce a gas pathway within a hydrophilic PTL. By selectively modifying of a conventional hydrophilic PTL with superhydrophobic polytetrafluoroethylene (PTFE) via a facile spray-coating method, we engineered a distinct out-of-plane wetting gradient. This structural design physically decouples the liquid and gas pathways by providing preferential fluidic channels. Specifically, the hydrophilic domains secure electrolyte permeation toward the catalyst layer, while the superhydrophobic regions facilitate unidirectional gas evacuation.
This directional gas evacuation drives continuous gas removal by lowering the local gas pressure, thereby preventing bubble accumulation at the catalysts layer. Consequently, the modified PTL significantly mitigates mass transport overpotential and enhances overall water electrolysis efficiency. Furthermore, this surface engineering approach is universally adaptable to various PTLs and is easily applied to large-area (225 cm2) and short-stack systems, offering a highly effective, adaptable surface-wetting strategy for advanced water electrolyzers.
To address this limitation from a surface wetting perspective, we introduce a gas pathway within a hydrophilic PTL. By selectively modifying of a conventional hydrophilic PTL with superhydrophobic polytetrafluoroethylene (PTFE) via a facile spray-coating method, we engineered a distinct out-of-plane wetting gradient. This structural design physically decouples the liquid and gas pathways by providing preferential fluidic channels. Specifically, the hydrophilic domains secure electrolyte permeation toward the catalyst layer, while the superhydrophobic regions facilitate unidirectional gas evacuation.
This directional gas evacuation drives continuous gas removal by lowering the local gas pressure, thereby preventing bubble accumulation at the catalysts layer. Consequently, the modified PTL significantly mitigates mass transport overpotential and enhances overall water electrolysis efficiency. Furthermore, this surface engineering approach is universally adaptable to various PTLs and is easily applied to large-area (225 cm2) and short-stack systems, offering a highly effective, adaptable surface-wetting strategy for advanced water electrolyzers.
