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

Summary 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.