Optimization of the membrane electrode assembly for an alkaline water electrolyser based on the catalyst-coated membrane

Electrode configurations study for alkaline direct ethanol fuel cells

“…[2] Whereby the CCM variant is extremely useful, as a direct connection can be formed by applying the catalyst layer and the anion exchange ionomer on it, as shown in literature. [20,21] However, therefore research is needed to reduce membrane swelling during anionic conversion or doping with KOH and to develop chemically and thermally stable anion exchange ionomers. [2]…”

“…Several studies have been performed on fabrication optimization for alkaline electrolysis with anion exchange membranes. For example, Plevová et al [21] developed a membrane and ionomer for the alkaline water electrolyzer which can be used to produce with a computer-controlled ultrasonic dispersion deposition method CCMs. Ito et al [20] discovered that the CCM-cathode and CCS-anode is the most appropriate configuration when using commercial membranes.…”

High-current density alkaline electrolyzers: The role of Nafion binder content in the catalyst coatings and techno-economic analysis

“…Nevertheless, as a preliminary step, it remains crucial to optimize Pt-based cathodes for AELs, for example by screening the optimal amount of both Pt, conductive additives ( e.g ., carbon materials) and binding agents ( e.g ., polymeric binders). In fact, while the optimization of the binder type and content is crucial for the design of catalyst coatings in electrode membrane assemblies (MEAs) of polymer electrolyte membrane electrolyzers ( Mayerhöfer et al, 2021 ) ( i.e ., PEMELs ( Xu and Scott, 2010 ), ( Trinke et al, 2019 ) and AEMELs ( Cho et al, 2018 ), ( Cho et al, 2017a ), ( Masel et al, 2016 ), ( Chen et al, 2021 ), ( Li et al, 2020 ), ( Plevová et al, 2022 ), ( Koch et al, 2021 )) or proton-exchange membrane fuel cells, ( Jeon et al, 2010 ), ( Cho et al, 2017b ), ( Antolini et al, 1999 ) this task has not been fully covered for AELs. Actually, in both PEMELs ( Xu and Scott, 2010 ), ( Bühler et al, 2019 ) and AEMELs, ( Cho et al, 2018 ), ( Cho et al, 2017a ), ( Masel et al, 2016 ) the incorporation of ionomer binders in the catalysts coating extends the ion conduction from the bulk of the membrane to the surface of the catalysts (guaranteeing the ion transport from the wet electrode ( i.e ., anode) to dried one ( i.e ., cathode).…”

“…In general, the removal of gaseous hydrogen from the catalyst coating can be impeded when binder content exceeds a certain threshold, as a consequence of the decrease of the electrode porosity. ( Plevová et al, 2022 ), ( Koch et al, 2021 ) Such an effect may also lead to supersaturation of dissolved hydrogen, which in PEMELs has been identified as a cause of pronounced gas crossover losses. ( Xu and Scott, 2010 ), ( Trinke et al, 2019 ), ( Bühler et al, 2019 ) Nevertheless, the incorporation of the binder should ensure long-term mechanical (and, thus, electrochemical) stability of the catalysts coating when it operates at high current density into practical AELs.…”

“…( Xu and Scott, 2010 ), ( Trinke et al, 2019 ), ( Bühler et al, 2019 ) Nevertheless, the incorporation of the binder should ensure long-term mechanical (and, thus, electrochemical) stability of the catalysts coating when it operates at high current density into practical AELs. ( Cho et al, 2018 ), ( Plevová et al, 2022 ), ( Koch et al, 2021 ) In the latter, temperature as high as 80 °C and continuous liquid electrolyte circulation may also affect the electrode performances ( Buttler and Spliethoff, 2018 ). Noteworthy, discrepancies between the catalysts performances measured in three-electrode cell configuration and electrolysis systems (including MEAs based on catalyst coated membranes -CCMs- or gas diffusion electrodes -GDEs-) have been recently discussed for both PEMEL and AEMELs, ( Schröder et al, 2021 ), ( Alinejad et al, 2020 ), ( Ehelebe et al, 2022 ) but not for AELs, likely because they traditionally operate at current densities inferior to PEMELs and AEMELs, ( Buttler and Spliethoff, 2018 ) i.e ., not very far from those recorded in three-electrode cell setups.…”