Oxygen ion conductor using layered cobalt oxide and fuel cell using the same

摘要

PPROBLEM TO BE SOLVED: To provide a mixed conductor formed of a less toxic stable material and sufficiently having both oxygen ion conductivity and electron conductivity even at a temperature around 500C. PSOLUTION: The cobalt oxide used for this oxygen ion conductor is expressed by a composition of chemical formula R AE MSB2/SBOSB5+x/SB, and having a stratiform perovskite type crystal structure. In the formula, x satisfies 0x1; R is one element out of La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho and Y or an element group comprising an arbitrary combination thereof; AE is a Ba element, or a substance wherein a part of Ba elements are replaced with either of Sr element and Ca element or both the elements; and M is a Co element or a substance wherein a part of Co elements is replaced with one element out of Ti, V, Cr, Mn, Fe, Ni and Cu or an element group comprising an arbitrary combination thereof. The chemical diffusion coefficient Dc of the oxygen ions in the cobalt oxide has a comparatively large value that is about 10SP-7/SPcmSP2/SP/s at a temperature around 300C. PCOPYRIGHT: (C)2005,JPO&NCIPI