Preparation and Ion Conductivity Properties of Bi1.8Gd0.1Er0.1‐xCaxO3‐δ Electrolyte

During the doping modification of bismuth oxide‐based electrolytes, a modified sample exhibiting the coexistence of δ‐Bi 2 O 3 and CaBi 6 O 10 phases was discovered. Crystallographic and surface morphological analyses revealed that this series of samples were dense two‐phase mixtures, with the composition of the CaBi 6 O 10 phase increasing in proportion to the doping of the Ca element. Conductivity measurements demonstrated that moderate Ca 2+ doping, or the presence of a moderate amount of CaBi 6 O 10 phase, enhanced the ionic conduction properties of the bismuth oxide. Notably, the Bi 1.8 Gd 0.1 Er 0.05 Ca 0.05 O 3‐δ sample exhibited excellent conductivity, reaching 0.293 S·cm −1 at 800 °C, while the fuel cell assembled with the BGEC05 electrolyte achieves a power output of 0.46 W·cm −2 at 700 °C. The δ‐Bi 2 O 3 phase provides a high concentration of oxygen vacancies, and the partial substitution of Ca 2+ increases the oxygen vacancy concentration and promotes the formation of the secondary peak CaBi 6 O 10 , while the CaBi 6 O 10 phase provides a fast transport channels, synergistically realizing efficient oxygen ion transport.