Proton conductor
View Patent ↗An exemplary proton conductor according to the present disclosure has a perovskite-type crystal structure expressed by the compositional formula A a B 1-x B′ x O 3-δ , where A is at least one selected from among group 2 elements; B is a group 4 element or Ce; B′ is a group 3 element, a group 13 element, or a lanthanoid element; 0.5<a≦1.0, 0.0≦x≦0.5, and 0.0≦δ<3; and the charge of the above compositional formula is deviated from electrical neutrality in a range of −0.13 or more but less than +0.14.
1. A proton conductor having a perovskite-type crystal structure expressed by the compositional formula A a B 1-x B′ x O 3-δ , wherein,
A is at least one selected from among group 2 elements;
B is at least one selected from among group 4 elements and Ce;
B′ is a group 3 element, a group 13 element, or a lanthanoid element;
0.5<a≦1.0, 0.0<x≦0.5, and 0.0<δ<3; and
charge of the compositional formula is deviated from electrical neutrality in a range of −0.13 or more but less than 0, where the charge of the compositional formula equals (2×a)+(4×(1−x))+(3×x)−(2×(3−δ)).
2. The proton conductor of claim 1 , wherein,
A is at least one selected from the group consisting of Ba, Sr, and Ca;
B is at least one selected from the group consisting of Zr, Ce, and Ti; and
B′ is one selected from the group consisting of Yb, Y, Nd, and In.
3. The proton conductor of claim 1 , wherein the values a, x and δ are determined based on quantitative measurements of elements composing the proton conductor.
4. The proton conductor of claim 1 , wherein an activation energy of proton conduction in a temperature range of not less than 100° C. and not more than 500° C. is 0.1 eV or less.