1. Progress on CRM reduction in HT electrolysers
• Innovative CRM‑free/lean materials (SOEL & PCCEL):
CEA: Al2O₃ and MgAl2O₄ added to Ni/YSZ cermet enable thinner electrodes with maintained strength; Ni‑3YSZ‑Al‑Mg composite shows major mechanical improvement vs. state‑of‑the‑art Ni‑3YSZ.
DLR: New perovskite LSCTN characterized as Ni/REE‑free alternative for Ni‑cermet; performance: 1.17 A/cm² @ 860 C, 1.2 V; 0.54 A/cm² @ 770 C, 1.2 V (Target 9 achieved).
DTU: CRM‑free SOEL air electrode based on LSF: Rp = 0.156 Ω·cm² @ 750C; degradation 3.2%/1000 h @ 750C, 0.5 A/cm² (Target 8 not yet achieved).
CEA: New La‑chromate perovskites with Sr→Ca substitution (LaSrCrMn, LaCaCrMn, LaCaCrFe). Best Rp = 8 Ω·cm² @ 750 C for LCCF without current collector.
SINTEF: CRM‑free PCCEL steam electrode using BZCY electrolyte + PBSCF electrode. Rp = 0.05 Ω·cm² @ 750 C (Target 8 achieved).
• Improved manufacturing protocols:
Magnetron sputtering (SINTEF/EPFL): SINTEF is developing a CeO2 barrier layer for PCCEL electrodes. CeO2 interlayer improves bonding and reduces ohmic resistance. EPFL developed dense CYO layers. Low deposition rate (500–700 nm) yields finer, denser layers. Ohmic resistance increases over time due to Sr segregation.
Tape casting (SINTEF): Proton‑conducting half‑cells with thin electrolytes (reduced from 30 µm to 18 µm). Electrolyte thickness and sintering temperature were optimized to obtain homogeneous, defect-free samples.
High‑throughput sputtering (CEA): Gradient zirconia→ceria interface to reduce resistivity. Optimized GDC thin films; EIS used to separate grain vs. grain‑boundary contributions. New setup under development for barrier‑layer resistance.
2. Progress on CRM reduction in LT electrolysers/fuel cells
• PFAS‑free PEM ionomers:
FZJ: PFAS‑free SFS‑28/OPBI membranes (ionic/covalent crosslinking), IEC optimized at 1.5 meq·g⁻¹.
SINTEF: 26 µm SFS‑28/OPBI membranes show PEMFC performance comparable to Nafion N212 (50 µm) in ASR, H2 permeation, cell performance, and durability.
• PFAS‑free/lean AEM ionomers:
FZJ: Polystyrene/OPBI AEMs with trimethylamine functionalization: conductivity 69 mS·cm⁻¹ @ 80 C, 90% RH; ASR 0.3 Ω·cm² @ 70 C, 1 M KOH (64 µm). Stable after 1000 h in 1 M KOH@85C.
• CRM‑free/lean electrocatalysts:
CNRS (Ni@N‑C HOR, AEMFC): Pyrolysis‑controlled shell composition correlates with HOR activity/stability. Optimized 1.5 h pyrolysis: 22% current loss after 4k cycles (−0.01→0.1 V vs RHE, 100 mV/s, 60 C, 0.1 M KOH). KPI achieved.
CNRS (Fe‑N‑C ORR, PEMFC): Two‑step pyrolysis with NH₄Cl in step 2 tunes microporosity and N‑basicity, improving ORR activity/durability.
DTU (Ni‑Mo HER, AEL/AEMEL): AI‑optimized electrodeposition yields 0.123 V overpotential @ 100 mA/cm², 80 C, 6 M KOH; ~0.187 V @ 10 mA/cm² (ECSA‑norm., RF=83, TS=70 mV/dec). Slight activity increase after 100 cycles. KPI achieved.
Tecnalia (Ni₁₋ₓFeₓOOH OER, AEMEL): Dip‑coated anodes on stainless steel (SS) and Ni felt: 283 mV (SS) and 260 mV (Ni) overpotential. NiFe8.9/0.1@SS shows lowest degradation (9%). Spray‑coated electrodes also tested in MEAs.
Tecnalia (NiMo & NiS HET, AEMEL): Dip‑coated catalysts on carbon GDL/Ni PTL. NiMo: 194 mV overpotential EoT. NiS: performance increases with S content (254 mV EoT).
DTU (Ir@IrOx/Nb‑TiO2 OER, PEMEL): Mass activity 174 mA mgIr⁻¹ @ 1.55 V (~3× commercial Alfa-Aesar (AA) IrO2); surface activity 1295 mA C⁻¹ (~10× AA IrO2). 1800 cycles (1.2–1.6 V) AST; 83% mass and 92% surface activity retained (AA IrO2: 43%/75%).
• Innovation in synthesis, manufacturing, & modelling:
DTU (Autonomous discovery): CatBot self‑driving lab for electrodeposition/testing. Explored ~10¹²‑size parameter space for Ni‑Mo HER; optimal coatings found within 30–40 experiments.
DLR (Flame spray pyrolysis): Pt‑embedded carbon‑network catalysts (Pt‑e‑Cn) with CRM‑free elements (Mn, Ni, Fe). Pt‑lean catalysts show 75% higher mass activity vs Pt/CHSA at 0.9 V.
DTU (Computational screening): Workflow screens Materials Project + GNoME (520k+ structures) for stability vs pH/potential, bandgap, and HHI to identify promising electrocatalysts.
CEA (MUSES/EuROPIUM modelling): PEMFC i‑V curves matched to MEAs with varying catalyst‑layer thickness and conditions. Model will guide optimization of ionomer/carbon ratio and distribution.
