Extended Data Fig. 4: Simulated electrolysis polarization curves under different conditions at 600 °C.

a, Comparison of simulated electrolysis polarization curves of the PC and CCS electrodes with different grain particle diameters. The experimental polarization curve of CCS electrode with a grain diameter of 0.3–0.4 µm is shown for validation of the simulated one. b, Simulated electrolysis polarization curve of the CCS electrode as a function of relative hydration capability. c, Simulated electrolysis polarization curve of the CCS electrode as a function of relative proton diffusivity.