An electrochemical cell having a composite alkali ion-conductive electrolyte membrane. Generally, the cell includes a catholyte compartment and an anolyte compartment that are separated by the composite alkali ion-conductive electrolyte membrane. The composite electrolyte membrane includes a layer of alkali ion-conductive material and one or more layers of alkali intercalation compound which is chemically stable upon exposure to a chemically reactive anolyte solution or catholyte solution thereby protecting the layer of alkali ion-conductive material from unwanted chemical reaction. The layer of alkali intercalation compound conducts alkali ions. The cell may operate and protect the alkali ion-conductive material under conditions that would be adverse to the material if the intercalation compound were not present. The composite membrane may include a cation conductor layer having additional capability to protect the composite electrolyte membrane from adverse conditions.

Provided is a layered double hydroxide oriented membrane in which layered double hydroxide plate-like particles are highly oriented in the approximately perpendicular direction and which is also suitable for densification. The layered double hydroxide oriented membrane of the present invention is composed of a layered double hydroxide represented by the general formula: M.sup.2+.sub.1-xM.sup.3+.sub.x(OH).sub.2A.sup.n−.sub.x/n.mH.sub.2O wherein M.sup.2+ is a divalent cation, M.sup.3+ is a trivalent cation, A.sup.n− is an anion having a valency of n, n is an integer of 1 or greater, x is 0.1 to 0.4, and m is 0 or greater, wherein when a surface of the oriented membrane is measured by X-ray diffractometry, a peak of a (003) plane is not substantially detected or is detected to be smaller than a peak of a (012) plane.

Provided is a layered double hydroxide oriented membrane in which layered double hydroxide plate-like particles are highly oriented in the approximately perpendicular direction and which is also suitable for densification. The layered double hydroxide oriented membrane of the present invention is composed of a layered double hydroxide represented by the general formula: M.sup.2+.sub.1-xM.sup.3+.sub.x(OH).sub.2A.sup.n−.sub.x/n.mH.sub.2O wherein M.sup.2+ is a divalent cation, M.sup.3+ is a trivalent cation, A.sup.n− is an anion having a valency of n, n is an integer of 1 or greater, x is 0.1 to 0.4, and m is 0 or greater, wherein when a surface of the oriented membrane is measured by X-ray diffractometry, a peak of a (003) plane is not substantially detected or is detected to be smaller than a peak of a (012) plane.

A multi-faceted zinc-air electrochemical cell design holistically leverages interactions between components, especially with respect to conductive carbons from differing sources, lamination and the resulting impact it has on the air electrode's surface and other additives that impact the relative hydrophilicity of the membrane and/or performance of the anode, to improve the overall reliability and performance of the resulting battery.

A multi-faceted zinc-air electrochemical cell design holistically leverages interactions between components, especially with respect to conductive carbons from differing sources, lamination and the resulting impact it has on the air electrode's surface and other additives that impact the relative hydrophilicity of the membrane and/or performance of the anode, to improve the overall reliability and performance of the resulting battery.

The electrolyte membrane of the present disclosure includes a plurality of crystal domains. At least one of the crystal domains includes a first crystal subdomain and a second crystal subdomain. Each of the first crystal subdomain and the second crystal subdomain includes Ba, Zr, M, and O. M is a trivalent element. The concentration of M in the first crystal subdomain is different from the concentration of M in the second crystal subdomain.

The electrolyte membrane of the present disclosure includes a plurality of crystal domains. At least one of the crystal domains includes a first crystal subdomain and a second crystal subdomain. Each of the first crystal subdomain and the second crystal subdomain includes Ba, Zr, M, and O. M is a trivalent element. The concentration of M in the first crystal subdomain is different from the concentration of M in the second crystal subdomain.

The fuel cell system of the present disclosure includes: a fuel cell that includes a membrane electrode assembly including a proton conducting ceramic electrolyte membrane, a cathode disposed on a first surface of the electrolyte membrane, and an anode disposed on a second surface of the electrolyte membrane, the fuel cell generating electric power through an electrochemical reaction using a fuel gas and an oxidant gas; a power source that applies a voltage to the fuel cell; and a controller. In a shutdown process, the controller controls the power source to apply the voltage to the fuel cell such that a terminal voltage of the fuel cell is equal to or higher than an open circuit voltage of the fuel cell.

The fuel cell system of the present disclosure includes: a fuel cell that includes a membrane electrode assembly including a proton conducting ceramic electrolyte membrane, a cathode disposed on a first surface of the electrolyte membrane, and an anode disposed on a second surface of the electrolyte membrane, the fuel cell generating electric power through an electrochemical reaction using a fuel gas and an oxidant gas; a power source that applies a voltage to the fuel cell; and a controller. In a shutdown process, the controller controls the power source to apply the voltage to the fuel cell such that a terminal voltage of the fuel cell is equal to or higher than an open circuit voltage of the fuel cell.

The present invention to provide a highly proton conducting metal organic material constituting of phosphate ester based ligand immobilized via gelation with Fe.sup.3+ ion in DMF which is used as conducting electrolyte in PEFMCs.