Increasing the performance of an anion-exchange membrane electrolyzer operating in pure water with a nickel-based microporous layer

Anion-exchange membrane water electrolysis (AEMWE) suffers from low performance compared with mainstream electrolysis techniques. Attempts at improvement have been confined to the development of membranes and electrodes. Here, in the quest of increasing the performance of AEMWE, a well-designed liquid/gas-diffusion layer (LGDL), termed as NiMPL-PTL, was developed by introducing nickel-based microporous layers (MPLs) on the top of a porous transport layer (PTL). The low tortuosity of this NiMPL-PTL reduced the capillary pressure and bubble point, which led to lower transport polarization. Moreover, the NiMPL-PTL decreased the interfacial contact resistance (ICR) by increasing the contact area between the PTL and the membrane electrode assembly (MEA). NiMPL-PTL, therefore, led to measurable performance improvements in the AEMWE operated in pure water: 290 mV lower voltage at 0.5 A cm−1 for AEMWE with MEA having precious- or nonprecious-metal-based catalyst, compared with similar cells but without NiMPL-PTL.