The disclosed technology generally relates to energy storage devices, and more particularly to energy storage devices comprising frustules. According to an aspect, a supercapacitor comprises a pair of electrodes and an electrolyte, wherein at least one of the electrodes comprises a plurality of frustules having formed thereon a surface active material. The surface active material can include nanostructures. The surface active material can include one or more of a zinc oxide, a manganese oxide and a carbon nanotube.

A metal air battery system is provided with: a battery device including a negative electrode, a metal body electrically connected to the negative electrode, and a positive electrode and having a chamber which is defined between the negative electrode and the metal body and through which an electrolytic solution flows; an oxygen separation device for separating oxygen from air; and a bubbling device for supplying a gas containing oxygen separated by the oxygen separation device into the electrolytic solution supplied to the chamber while bubbling the gas.

The present invention relates to an electrode comprising an electrically conductive substrate of which at least one portion of the surface is covered with a metal deposit of copper, the surface of said deposit being in an oxidised, sulphurised, selenised and/or tellurised form and the deposit having a specific surface area of more than 1 m.sup.2/g; a method for preparing such an electrode; and a method for oxygenising water with dioxygen involving such an electrode.

A method of producing electrical power includes: a cathode having a porphyrin precursor attached to a substrate, and having a first enzyme, wherein the first enzyme reduces oxygen; an anode having a first region of an anode substrate and having a gold nanoparticle composition located thereon, and having a second region of the anode substrate having an enzyme composition located thereon, wherein the enzyme composition includes a second enzyme, wherein the first region and second region are separate regions; and a neutral fuel liquid in contact with the anode and cathode, the neutral fuel liquid having a neutral pH and a fuel reagent; and operating the fuel cell to produce electrical power with the neutral fuel liquid having the neutral pH and the fuel reagent.

The disclosure provides a method for forming noble metal nanostructures on a support. The method comprises mixing one or more noble metal precursor with a first solvent and a base to obtain a noble metal precursor solution; feeding the noble metal precursor solution to a spiral tube reactor; heating the spiral tube reactor containing the noble metal precursor solution to reduce the one or more noble metal precursor to obtain noble metal nanostructures; and mixing a support ink with the noble metal nanostructures obtained after heating, wherein the support ink comprises a second solvent, the support and an ink acid. There are also provided noble metal nanostructures on a support and a use thereof as an electro-catalyst in an electrode for fuel cell applications.

A cathode in a solid oxide fuel cell containing AgPrCoO.sub.3. The operating temperature range of the cathode is from about 400° C. to about 850° C.

A cathode of a metal-air battery includes an electrically conductive metal oxide in a three-dimensional (3D) network structure, wherein the electrically conductive metal oxide of the three-dimensional network structure is in a form of a plurality of strands, wherein a strand of the plurality of strands has an aspect ratio in a range of about 10 to about 10.sup.7, and wherein the three-dimensional network structure has a porosity of about 70 volume percent to about 95 volume percent, based on a total volume of the three-dimensional network structure.

An electrode catalyst layer for electrochemical cells includes a first catalyst layer and a second catalyst layer. The first catalyst layer has a cell resistance measured at 80° C. and 40% RH lower than that of the second catalyst layer. The electrode catalyst layer for electrochemical cells is used with the first catalyst layer being disposed on an electrolyte membrane side relative to the second catalyst layer. It is preferable that a first catalytically active component contained in the first catalyst layer and a second catalytically active component contained in the second catalyst layer each independently contain at least one element selected from the group consisting of platinum, palladium, ruthenium, and iridium.

An anode catalyst layer for a fuel cell includes: electrode catalyst particles; a carbon carrier carrying the electrode catalyst particles; water electrolysis catalyst particles; a proton-conductive binder; and a graphitized carbon, wherein the content of the graphitized carbon in the anode catalyst layer for a fuel cell is 3-70 mass % with respect to the total mass of the electrode catalyst particles, the carbon carrier, and the graphitized carbon.

An electrode catalyst layer for fuel cells capable of effectively preventing reduction of cell voltage in a high current density region. The electrode catalyst layer contains a catalyst-on-support composed of a support made of a conductive inorganic oxide having a catalyst supported thereon and a hydrophilic material. The hydrophilic material is an agglomerate including hydrophilic conductive particles. The content of the hydrophilic material in the catalyst layer is 2 mass % or higher and lower than 20 mass % relative to the sum of the support and the hydrophilic material. The ratio of the particle size d1 of the hydrophilic particles to the particle size D of the catalyst-on-support is 0.5 to 3.0. The ratio of the particle size d2 of the hydrophilic material to the thickness T of the catalyst layer is 0.1 to 1.2.