Oriented intergrowth of the catalyst layer in membrane electrode assembly for alkaline water electrolysis

Abstract

The application of membrane electrode assemblies is considered a promising approach for increasing the energy efficiency of conventional alkaline water electrolysis. However, previous investigations have mostly focused on improving membrane conductivity and electrocatalyst activity. This study reports an all-in-one membrane electrode assembly obtained by de novo design. The introduction of a porous membrane readily enables the oriented intergrowth of ordered catalyst layers using solvothermal methods, leading to the formation of an all-in-one MEA for alkaline water electrolysis. This all-in-one MEA features ordered catalyst layers with large surface areas, a low-tortuosity pore structure, integrated catalyst layer/membrane interfaces, and a well-ordered OH- transfer channel. Owing to this design, a high current density of 1000 mA cm−2 is obtained at 1.57 V in 30 wt% KOH, resulting in a 94% energy efficiency. This work highlights the prospects of all-in-one membrane electrode assemblies in designing next-generation high-performance alkaline water electrolysis.

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

“…Due to the significant differences in physicochemical properties of the CLs and AEM, interfacial delamination between CLs and AEM can occur and negatively impact the AEMWE performance, especially under a low-concentrated KOH electrolyte or pure water feeding mode. 318 The gap between CLs and AEM will 236 2, 246 3, 209 4, 229 5, 230 6, 18 7, 194 8, 20 9, 211 10,240 11, 241 12, 233 13, 21 14, 205 15, 219 16, 191 17, 312 18, 234 19. 245 significantly increase the ionic transfer resistance at the interface.…”

“…Due to the significant differences in physicochemical properties of the CLs and AEM, interfacial delamination between CLs and AEM can occur and negatively impact the AEMWE performance, especially under a low-concentrated KOH electrolyte or pure water feeding mode. 318 The gap between CLs and AEM will significantly increase the ionic transfer resistance at the interface. Thus, the degradation of CL/AEM interface structures should also be considered.…”

Surface and near-surface engineering design of transition metal catalysts for promoting water splitting

“…The design of a three-dimensional interconnected structure is essential for ensuring fast mass transport and site accessibility, as individual channels are easily blocked due to the slow diffusion of reactants and gas products. 123 Wang's group proposed a nanoscale grade-separation strategy to prepare ordered three-dimensional interconnected sub-5 nm pores that achieve few-nanometer confined mass transport. 124 The high mass transfer efficiency is attributed to three main factors.…”

Transforming NiFe layered double hydroxide into NiFePx for efficient alkaline water splitting

“…For this reason, many countries are investing heavily in hydrogen generation and storage technologies to tackle climate change and achieve carbon neutrality. 1–3…”

“…For this reason, many countries are investing heavily in hydrogen generation and storage technologies to tackle climate change and achieve carbon neutrality. [1][2][3] Producing hydrogen by water splitting is an environmentally friendly strategy without any pollutants, and is one of the most popular elds in energy research today. Alkaline water electrolysis (AWE) and proton-exchange membrane water electrolysis (PEMWE) are two main ways of electrochemical water splitting.…”