Oxygen bubble transport in a porous transport layer of polymer electrolyte water electrolyzer

Considerable efforts have been taken to develop an effective porous transport layer (PTL) that can mitigate the mass transport resistance of proton exchange water electrolysis (PEWE). Several experiments have been conducted to understand the underlying mechanisms in the PTL that are responsible for bubble removal and performance improvement. Here, we investigate the dynamic behavior of oxygen bubble in a PTL using a free surface model in a lattice Boltzmann framework. Various PTL properties are examined to gain a fundamental understanding of the bubble transport phenomena and perform effective bubble removal from the PTL at a high current density operation. We report on the bubble volume fraction and bubble distribution inside the PTL to elucidate the impact of the PTL properties on the bubble transport behavior. Oxygen bubble transport characteristics that determine the bubble removal time have been extensively studied. The findings will enable more reliable bubble management and the development of related high-power PEWE technologies.