The electrochemical cell according to the present invention has an anode, a cathode, and a solid electrolyte layer disposed between the anode and the cathode. The cathode contains a main phase and a second phase. The main phase is configured with a perovskite oxide which is expressed by the general formula ABO.sub.3 and includes at least one of Sr and La at the A site. The second phase is configured with SrSO.sub.4 and (Co, Fe).sub.3O.sub.4. An occupied surface area ratio of the second phase in a cross section of the cathode is less than or equal to 10.5%.

An expanded graphite sheet and a battery using the expanded graphite sheet are provided, that can inhibit the expanded graphite sheet from swelling even when the expanded graphite sheet is used for, for example, a positive electrode for an air battery. An expanded graphite sheet includes an expanded graphite and has a surface water contact angle of greater than or equal to 90 degrees and a surface resistivity of less than or equal to 70 mΩ/sq. It is desirable that a polyolefin resin be contained in the expanded graphite sheet in a dispersed state. It is desirable that the polyolefin resin be polypropylene.

A method for producing a membrane electrode assembly for a fuel cell comprising a proton exchange polymer membrane, catalyst layers, and first and second gas diffusion layers, the method comprising the following steps: a) forming a catalytic layer coating on a first surface of the membrane, the opposite surface being supported by a spacer; b) forming a catalytic layer coating on a first surface of the first gas diffusion layer; c) bringing the first surface of the first gas diffusion layer into contact with the surface opposite to the said first surface of the membrane, after removing the spacer, and bringing the first surface of the membrane into contact with a surface of the second gas diffusion layer.

A fuel cell includes a proton-exchange membrane, and a cathode and anode fixed on its opposite sides. The anode delimits a flow conduit between a molecular-oxygen inlet area and a water outlet area. The cathode includes a support for catalyst material. The support has first and second materials to which catalyst is fixed, the first material being a graphitized material. The second material has a resistance to corrosion by oxygen that is greater than that of the first material. A quantity of the second material at the inlet area is greater than a quantity of the second material at the water outlet. The cathode comprises a first layer including the first material and a second layer including the second material. A thickness of the second layer decreases between the molecular-oxygen inlet area and the water outlet area.

A method of making an interconnect for a solid oxide fuel cell stack includes contacting an interconnect powder located in a die cavity with iron, the interconnect powder including a chromium and iron, compressing the interconnect powder to form an interconnect having ribs and fuel channels on a first side of the interconnect, such that the iron is disposed on tips of the ribs; and sintering the interconnect, such that the iron forms an contact layer on the tips of the ribs having a higher iron concentration than a remainder of the interconnect. A glass containing cathode contact layer having a glass transition temperature of 900° C. or less may be located over the rib tips on the oxidant side of the interconnect.

There is disclosed a cartridge for a portable electronic device power system configured as a flat, prismatic, air-breathing zinc-air battery comprising (a) an anode assembly having a structural backbone, current collectors, and a gel solution comprising a mixture of amalgamated zinc powder, aqueous potassium hydroxide and a gelling agent, (b) a porous separator sheet, and (c) an air-breathing cathode having an electrode impregnated with reductive catalyst, and (d) a serialized electrical connectivity path having low ohmic resistance characteristics. More specifically, there is disclosed a prismatic format, flat rectangular disposable primary battery having two or more zinc-air batteries connected in series, wherein each zinc air battery comprises: (a) an anode assembly having a structural backbone, current collectors, and a gel solution comprising a mixture of amalgamated zinc powder, aqueous potassium hydroxide and a gelling agent, (b) a porous separator sheet, and (c) a catalytically active oxygen-reductive cathode.

A catalyst layer for a fuel cell contains a support and a catalyst supported on the support. The support contains a titanium oxide having a crystal phase of Ti.sub.2O. The ratio of total abundance of trivalent Ti and divalent Ti (W2) to abundance of tetravalent Ti (W1), W2/W1, is 0.1 or more as determined on the surface of the catalyst layer by X-ray photoelectron spectroscopy. The catalyst is preferably made of at least one metal selected from platinum, iridium, and ruthenium, or an alloy thereof. Also, the catalyst layer for a fuel cell preferably further contains an ionomer, and the ratio of mass of the ionomer (I) to mass of the catalyst-supporting support (S), I/S, is preferably 0.06 or more and 0.23 or less.

A membrane electrode assembly including: an anode electrode; a cathode electrode; and a polymer electrolyte membrane; wherein the cathode includes a first cathode catalyst sublayer including a first precious metal catalyst composition and a first ionomer composition including a first ionomer and a second ionomer; and a second cathode catalyst sublayer including a second precious metal catalyst composition and a second ionomer composition including a third ionomer; wherein the first ionomer is different from the second ionomer in at least one of chemical structure and equivalent weight.

A cell stack device includes a cell stack, a holding member, and a positive electrode terminal. The cell stack is constructed by stacking a plurality of cells. The holding member holds the cells. The positive electrode terminal functions as a positive electrode when power generated by the cell stack is output to the outside. The potential of the positive electrode terminal is not more than that of the holding member.

A metal air flow battery includes an electrochemical reaction unit and an oxygen exchange unit. The electrochemical reaction unit includes an anode electrode, a cathode electrode, and an ionic conductive membrane between the anode and the cathode, an anode electrolyte, and a cathode electrolyte. The oxygen exchange unit contacts the cathode electrolyte with oxygen separate from the electrochemical reaction unit. At least one pump is provided for pumping cathode electrolyte between the electrochemical reaction unit and the oxygen exchange unit. A method for producing an electrical current is also disclosed.