The phase composition and electrochemical performance of CaZr_1−xYb_xO_3−δ proton conductor

To study the electrochemical properties of Yb-doped CaZrO₃ in more detail, the CaZr_1−xYb_xO_3−δ (x = 0.000, 0.025, 0.050, 0.075, and 0.100) solid electrolyte specimens were prepared by high-temperature solid-state method at the temperatures of 1523 K and 1873 K for 8 h. XRD, SEM, EDS, and electrochemical workstation were used to test the micromorphology and electrochemical performance of the electrolyte samples. When the doping amount of Yb is 0.05, the electrolyte sample has excellent electrical properties. The total conductivity of electrolyte CaZr_0.95Yb_0.5O_3−δ is 1.13 × 10⁻⁵ to 1.28 × 10⁻³ S/cm and the conductivity activation energy falls in 0.69–1.34 eV in hydrogen and oxygen atmosphere at 973–1173 K. The chemical diffusion coefficient of hydrogen in CaZr_0.95Yb_0.05O_3−δ electrolyte is between 1.55 × 10⁻⁶ and 5.82 × 10⁻⁶ cm²/s in the temperature range of 973 to 1373 K, and the diffusion activation energy is 12,278 kJ/mol.