Effect of pore structures in nickel‐based porous transport layers for high‐performance and durable anion‐exchange membrane water electrolysis

Abstract

Investigation of the anode porous transport layer (PTL) is crucial for the commercialization of anion-exchange membrane water electrolysis (AEMWE).Recently, nickel foam (Ni-foam) has been employed as an alternative to the conventional titanium-based PTL (Ti-felt) and strategies to improve its performance and durability have been developed. However, few studies have investigated the effect of pore structures in Ni-foam and the applications of other Ni-based PTLs have not been reported. In this study, two Ni-based PTLs with different pore structures, Ni-foam and nickel felt (Ni-felt), were applied and investigated to attain a suitable microstructure in the PTL. The AEMWEs with the optimized Ni-foam and Ni-felt showed superior performance and durability than that with the conventional Ti-felt. In particular, the application of Ni-foam as an anode PTL resulted in higher performance than that of Ni-felt, which is attributed to the reduced mass transfer resistance caused by the interconnected pore structure. The Ni-foam PTL optimized in this study can be an efficient alternative to the conventional Ti-felt PTL because it can facilitate the enhanced AEMWE performance and durability.

Predicting the Topological and Transport Properties in Porous Transport Layers for Water Electrolyzers

“…The normalized effective gas (here oxygen) diffusion coefficient and tortuosity in the IP and TP directions of PTLs as functions of the porosity, fiber radii, and anisotropy parameters are shown in Figure . Figure a indicates that the gas diffusion coefficient of PTLs with different porosity calculated by PSM is in good agreement with the numerical calculations and experimental results from the literature. ,, An increase in the porosity leads to an increase in the gas diffusion coefficient both in the IP and TP directions. The IP direction features a higher diffusion coefficient compared to the TP direction.…”

“…Studies exploring the relationship between the PTL structure and PEM electrolyzer performance provide more direct and effective insight into the application of PTLs. ,,,,− For instance, in the work of Majasan et al, , several PTL structures were characterized using scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), and X-ray computed microtomography (XCT) to obtain the structural information such as the porosity and mean pore diameter (MPD). Subsequently, polarization curves and impedance spectra were measured and used to analyze the performance of electrolysis cells equipped with these PTLs.…”

“…A detailed electrochemical loss breakdown was used to analyze the activation, ohmic, and mass transport losses of each PTL type over a range of conditions. Some work was also devoted to exploring the comprehensive impact of PTL thickness on the structural morphology, transport properties, two-phase flow, and electrochemical performances. ,,− It was generally agreed that for specific operating conditions, there would usually be an optimum thickness to weigh the individual losses. In the experiments of Weber et al, they deduced that the optimal PTL thickness corresponds to around half of the flow field land size.…”

Synergistic Effects of Pyrrolic N/Pyridinic N on Ultrafast Microwave Synthesized Porous CoP/Ni2P to Boost Electrocatalytic Hydrogen Generation

“…The pore size distribution curve shows that N-CoP/Ni 2 P is mainly composed by a mesoporous and macroporous structure (Figure c). The presence of porous structure can increase the contact area between the water and catalyst, and the production of H 2 and O 2 can diffuse through the porous structure to release the active sites. , The microstructure of N-CoP/Ni 2 P is further studied by transmission electron microscopy (TEM). In Figure d,e, the TEM of N-CoP/Ni 2 P exhibits a porous structure.…”

Key components and design strategy of the membrane electrode assembly for alkaline water electrolysis

“…274 Park and co-workers investigated the effect of pore structures in Ni-based LGDLs on AEM water electrolysis. 197 For the Ni-felt LGDLs, the decreased thickness by compression improved electrolysis performance because of the decreased electron pathway and thereby reduced ohmic resistance. As for Ni foam LGDLs, the trade-off between electrical conductivity and mass transfer can be optimized by adding a suitable compressing force.…”