A solid oxide fuel cell (SOFC) includes a ceramic electrolyte having a thickness of 100 microns or less, an anode laminated to a first side of the electrolyte, and a cathode located on a second side of the electrolyte opposite to the first side.

A solid oxide fuel cell (SOFC) includes a ceramic electrolyte having a thickness of 100 microns or less, an anode laminated to a first side of the electrolyte, and a cathode located on a second side of the electrolyte opposite to the first side.

An object of the invention is to increase the output power of a solid oxide fuel cell by making a lower electrode layer porous so as to form a three-phase interface and reducing a thickness of a solid electrolyte layer to 1 micrometer or less. A fuel cell according to the invention includes a first electrode layer at a position where an opening formed in a board is covered, and a solid electrolyte layer having a thickness of 1000 nm or less. At least a part of a region of the first electrode layer covering the opening is porous (see FIG. 5).

An object of the invention is to increase the output power of a solid oxide fuel cell by making a lower electrode layer porous so as to form a three-phase interface and reducing a thickness of a solid electrolyte layer to 1 micrometer or less. A fuel cell according to the invention includes a first electrode layer at a position where an opening formed in a board is covered, and a solid electrolyte layer having a thickness of 1000 nm or less. At least a part of a region of the first electrode layer covering the opening is porous (see FIG. 5).

A membrane electrode assembly of an electrochemical device includes a proton conductive solid electrolyte membrane and an electrode including Ni and an electrolyte material which contains as a primary component, at least one of a first compound having a composition represented by BaZr.sub.1-x1M.sup.1.sub.x1O.sub.3 (M.sup.1 represents at least one element selected from trivalent elements each having an ion radius of more than 0.720 A° to less than 0.880 A°, and 0<x.sub.1<1 holds) and a second compound having a composition represented by BaZr.sub.1-x2Tm.sub.x2O.sub.3 (0<x.sub.2<0.3 holds).

A membrane electrode assembly of an electrochemical device includes a proton conductive solid electrolyte membrane and an electrode including Ni and an electrolyte material which contains as a primary component, at least one of a first compound having a composition represented by BaZr.sub.1-x1M.sup.1.sub.x1O.sub.3 (M.sup.1 represents at least one element selected from trivalent elements each having an ion radius of more than 0.720 A° to less than 0.880 A°, and 0<x.sub.1<1 holds) and a second compound having a composition represented by BaZr.sub.1-x2Tm.sub.x2O.sub.3 (0<x.sub.2<0.3 holds).

Herein disclosed is a method of making a fuel cell including forming an anode, a cathode, and an electrolyte using an additive manufacturing machine. The electrolyte is between the anode and the cathode. Preferably, electrical current flow is perpendicular to the electrolyte in the lateral direction when the fuel cell is in use. Preferably, the method comprises making an interconnect, a barrier layer, and a catalyst layer using the additive manufacturing machine.

Herein disclosed is a method of making a fuel cell including forming an anode, a cathode, and an electrolyte using an additive manufacturing machine. The electrolyte is between the anode and the cathode. Preferably, electrical current flow is perpendicular to the electrolyte in the lateral direction when the fuel cell is in use. Preferably, the method comprises making an interconnect, a barrier layer, and a catalyst layer using the additive manufacturing machine.

A method of manufacturing by magnetron cathode sputtering an electrolyte film for use in solid oxide cells (SOC). This method comprises the steps consisting of heating a substrate to a temperature ranging from 200° C. to 1200° C.; followed by subjecting the substrate to at least two treatment cycles, each treatment cycle comprising: 1) depositing one layer of a metal precursor on the substrate by magnetron cathode sputtering of a target made up of the metal precursor, the sputtering being carried out under elemental sputtering conditions; followed by 2) oxidation-crystallisation of the metal precursor forming the layer deposited on the substrate in the presence of oxygen to obtain the transformation of the metal precursor into the electrolyte material; and in that the substrate is kept at a temperature ranging from 200° C. to 1200° C. for the entire duration of each treatment cycle.

The present invention relates to rhomboidal phase bismuth oxide that maintains electric conductivity of at least about 1×10.sup.−2 S/cm at temperature of about 500° C. for at least about 100 hours. In particular, the bismuth oxides of the invention have stable conductivity at a temperature range from about 500° C. to about 550° C.