Patent ID: 7153412

Claim:
An electrochemical element comprising: an oxide-ion conductive solid electrolyte; and an electrode comprising at least one component selected from a group consisting of (III) and (IV); (I) a perovskite oxide expressed by (A 1-x B x ) (C 1-y D y ) O 3-z , (II) an oxide expressed by (Ce 1-x P x ) O 2-z , (III) a mixture of said (I) and said (II), the proportion of said (II) in the mixture being 1 to 95% by weight; and (IV) a layered body formed by at least two layers, each layer including at least one component selected from a group consisting of said (I), said (II) and the mixture of said (I) and (II); wherein in (I) through (IV); symbol A represents La, Pr, Ce, Ca, Sr, or Ba; symbol B represents Sr, Ce or Ca; symbol C represents Cr, Mn, Fe, Co, Ti, Zr, or Ga; symbol D represents Cr, Ni, Mg, Zr, Ce, Fe, Al, or Co, and symbol P represents La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Tm, Yb, Ca, Y, Mg, Sr, Ba, Zr, Mn, Fe, or Cr, wherein X satisfies the condition of 0≦X≦0.5 and Y satisfies the condition of 0≦Y≦0.5, wherein the oxide-ion conductive solid electrolyte and the electrode are in contact with each other or are next to each other with another member between them.