A method for manufacturing a miniaturized electrochemical cell and a miniaturized electrochemical cell is provided. The method includes the following steps: a) forming a colloidal template of colloidal particles made of an electrically insulating material, on a substrate made of an electrically conducting material, b) depositing by electrodeposition in the void spaces of the colloidal template, at least three alternating layers forming a repeating unit, the alternating layers being made of an electron conducting material or a semi -conducting material, the intermediate layer(s) being made of a material M.sub.3 different from materials M.sub.1 and M.sub.2 constituting respectively the upper and lower layers, the material M3 having a standard potential lower than the standard potentials of the materials M.sub.1 and M.sub.2, c) removal of the material M.sub.3 of intermediate layer(s), and d) removal of the colloidal particles of the upper and lower layers to obtain the desired electrodes.

An electrode unit and an electrode system comprising the same, wherein the electrode unit has an electrode catalyst layer consisting of a material comprising electrically conductive diamond particles; the electrode system having the above electrode unit includes an anode and a cathode, and the anode and/or cathode employs the electrode unit, the electrode system further including a PEM film; the anode and the cathode are respectively disposed on two sides of the PEM film. The use of electrically conductive diamond particles as the electrode catalyst layer does not require the use of base materials such as metals or semiconductors or ceramics, and machining problem and the problem relating to the difference in thermal expansion coefficient do not exist, thereby significantly reducing the manufacturing cost.

Disclosed are a method for preparing a graphene dot-palladium hybrid having a nanosponge structure that includes reducing a palladium precursor in the presence of a carbon dot and sodium bromide, and a graphene dot-palladium hybrid catalyst prepared according to the method. The nanosponge structure of the graphene dot-palladium hybrid is encapsulated by a graphene dot. The carbon dot is doped with at least one heteroatom selected from the group consisting of nitrogen, sulfur, phosphorus, and boron.

Provided is a method of preparing an intermetallic catalyst. The method includes form core-shell particles including a transition metal oxide coating layer by irradiating ultrasonic waves to a precursor mixture solution including a noble metal precursor, a transition metal precursor, and a carrier to; forming intermetallic particles including a transition metal oxide coating layer by annealing the core-shell particles; and removing the transition metal oxide coating layer from the intermetallic particles.

An embodiment provides a catalyst for water electrolysis which includes an iridium mixed phase formed by physical mixing of two or more selected from metal iridium (Ir), iridium(III) oxide (Ir.sub.2O.sub.3), or iridium(IV) oxide (IrO.sub.2) and has a structure in which nanosheets composed of the iridium mixed phase are stacked. The catalyst for water electrolysis may exhibit high activity and stability for the oxygen evolution reaction in water electrolysis.

A fuel cell component including a fuel cell substrate and a nitride material. The material may be a nitride compound having a chemical formula A.sub.xB.sub.yN.sub.z, where A is a metal, B is a metal different than A, N is nitrogen, x>0, y<7 and 0<z<12. The nitride compound may have a ratio of a stoichiometric factor to a reactivity factor of greater than 1.0. The stoichiometric factor indicates the reactivity of a nitride compound with chemical species as compared to a baseline nitride compound. The reactivity factor indicates the reaction enthalpy of the nitride compound and the chemical species as compared to a baseline nitride compound and the chemical species. The nitride compound may be Fe.sub.3Mo.sub.3N, Ni.sub.2Mo.sub.3N, Ni.sub.2W.sub.3N, CuNi.sub.3N, Fe.sub.3WN, Zn.sub.3Nb.sub.3N, V.sub.3Zn.sub.2N or a combination thereof. The nitride compound may be Si.sub.6Y.sub.3N.sub.11, Ni.sub.2Mo.sub.4N, Fe.sub.3Mo.sub.5N.sub.6 or a combination thereof.

Provided is a method for forming noble metal nanoparticles on a support. In particular, the method includes heating precursors of the noble metal nanoparticles in a spiral glass tube reactor to reduce the precursors to form the noble metal nanoparticles on the support.

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.

Disclosed is a pouch type metal-air battery. In the pouch type metal-air battery, when the electrolyte inside the cell comes out of the electrode assembly by applying external pressure, the electrolyte does not reach the space partitioned by the gas diffusion layer, the electrode assembly and the exterior material, due to the step caused by the projection part of the gas diffusion layer. As such, a plurality of pores in the exterior material, which corresponds to the space, may not be blocked. Therefore, since oxygen selectively permeated from the exterior material flows into the gas diffusion layer, and flows into the electrode assembly through the diffusion portion of the gas diffusion layer, the contact resistance with pressure may improve and the initial driving conditions and driving reproducibility may be secured.

An adhesive layer is placed in a region outside an outer peripheral edge part of a second catalyst layer, on a second surface of an electrolyte membrane. A support frame is placed via the adhesive layer such that the second catalyst layer and a second gas diffusion layer are placed inside an opening of the support frame. A specific region as a region between the outer peripheral edge part of the second catalyst layer and an inner peripheral edge part of the opening of the support frame is present. A predetermined material is placed inside a recessed portion present on a surface of the adhesive layer inside the specific region, the predetermined material containing at least one of a first substance having an action of decomposing hydrogen peroxide and a second substance having an action of decomposing hydroxyl radicals.