The invention relates to electrochemical current sources, more particularly to metal-air current sources, and even more particularly to lithium-air current sources and their electrodes. A cathode comprises a base made of a porous electrically conducting material that is permeable to molecular oxygen, the working surface of which has a copolymer applied thereto, which is produced by the copolymerization of a monomeric transition metal coordination complex having a Schiff base and a thiophene group monomer. The monomeric transition metal coordination complex having a Schiff base can be, for example, a compound of the [M(R,R-Salen)], [M(R,R-Saltmen)] or [M(R,R-Salphen)] type, and the thiophene group monomer can be a compound selected from a thiophene group consisting of 3-alkylthiophenes, 3,4-dialkylthiophenes, 3,4-ethylenedioxythiophene or combinations thereof. A current source comprises the described cathode and an anode made from an active metal, in particular lithium, wherein the cathode and the anode are separated by an electrolyte containing ions of the metal from which the anode is made. It has been established that in this system, the copolymer exhibits the properties of an effective catalyst. The technical result is an increase in the specific energy, specific power and number of charge and discharge cycles of a metal-air current source.

A metal foil including on at least one of its sides a layer of a material including: a metal or a metal alloy, carbon, hydrogen, and optionally oxygen, the atomic percentage of the metal or of the metals of the alloy in the material ranging from 10 to 60%, the atomic percentage of carbon in the material ranging from 35 to 70%, the atomic percentage of hydrogen in the material ranging from 2 to 20%, and the atomic percentage of oxygen if present in the material being less than or equal to 10%. The metal foil can be used in the manufacture of a cathode of a lithium-ion electrochemical cell. The deposition of this layer reduces the internal resistance of the cell.

An electrode for redox flow batteries, the electrode being formed of a carbon fiber aggregate including a plurality of carbon fibers. Each of the carbon fibers has a plurality of pleats formed in the surface thereof. The ratio of L.sub.1 to L.sub.2, that is, L.sub.1/L.sub.2, is more than 1, where L.sub.1 is the peripheral length of a cross section of the carbon fibers and L.sub.2 is the peripheral length of a virtual rectangle circumscribing the cross section of the carbon fibers.

A bipolar plate for an electrochemical device, including a first bipolar plate layer and a second bipolar plate layer joined by a weld seam arrangement, wherein the first bipolar plate layer has a first and a second medium passage opening. The weld seam arrangement includes a first and a second medium channel weld seam, and a connecting weld seam which crosses the first and the second medium channel weld seams. Either a) the connecting weld seam is produced by a welding energy source which the first bipolar plate layer faced during the welding process, and the weld seam end of the connecting weld seam lies within the medium-conducting region of the bipolar plate which is surrounded by the first medium channel weld seam, and/or b) the connecting weld seam crosses the first medium channel weld seam and/or the second medium channel weld seam at least twice in each case.

Described and illustrated is an electrochemical cell, in particular a redox flow battery, with at least one cell frame and at least one electrode. The cell frame circumferentially encloses a cell interior. The cell frame has at least one feed channel for feeding electrolyte into the cell interior and at least one discharge channel for discharging electrolyte from the cell interior. The at least one cell frame has at least one finger element projecting into the cell interior and wherein the electrode is arranged at least in regions in the cell interior and on opposite sides of the at least one finger element. In order to achieve a more appropriate flow through, which reliably allows for a lower pressure loss and a higher power density, it is provided that the at least one feed channel and/or the at least one discharge channel is provided at least in sections in the finger element and that the at least one finger element has at least one outlet opening into the cell interior for the electrolyte to be fed and/or at least one inlet opening from the cell interior for the electrolyte to be discharged.

A gas diffusion layer for an electrolyser or for a fuel cell comprises a first nonwoven layer of metal fibers provided for contacting a proton exchange membrane, a second nonwoven layer of metal fibers, and a third porous metal layer. The first nonwoven layer of metal fibers comprises metal fibers of a first equivalent diameter. The second nonwoven layer of metal fibers comprises metal fibers of a second equivalent diameter. The second equivalent diameter is larger than the first equivalent diameter. The third porous metal layer comprises open pores. The open pores of the third porous metal layer are larger than the open pores of the second nonwoven layer of metal fibers. The second nonwoven layer is provided in between and contacting the first nonwoven layer and the third porous metal layer. The second nonwoven layer is metallurgically bonded to the first nonwoven layer and to the third porous metal layer. The thickness of the third porous metal layer is at least two timesand preferably at least three timesthe thickness of the first nonwoven layer.

An electrode for electrochemical applications is coated with a layer of a-C, wherein the layer of a-C comprises at least 10 each of first and second sub-layers, being (i) first sub-layers having high conductivity with a sp2 content of 60-95%, alternating with (ii) second sub-layers having high corrosion resistance with a sp2 content of 50-90%, wherein the sp2 content of the first sub-layers is at least 3% greater than the sp2 content of the second sub-layers. A method of making such electrodes comprises:a) depositing a first sub-layer comprising a-C, b) depositing a second sub-layer comprising a-C wherein the sp2 content of the first sub-layer is at least 3% greater than the sp2 content of the second sub-layer, and c) repeating the steps above to deposit at least 10 first sub-layers alternating with 10 second sub-layers, so as to produce the electrodes.

A bipolar plate assembly for a fuel cell includes a cathode plate disposed adjacent an anode plate. The cathode and anode plates are formed having a first thickness of a low contact resistance, high corrosion resistance material by a deposition process. The first and second unipolar plates are formed on a removable substrate, and a first perimeter of the first unipolar plate is welded to a second perimeter of the second unipolar plate to form a hermetically sealed coolant flow path.

Provided is a terminal assembly for an electrochemical battery comprising a terminal connector; a conductive flat-plate with an electrically conducting perimeter; an electrically insulating tape member; and a terminal bipolar electrode plate. The electrically insulating tape member is in between the conductive flat-plate and the terminal bipolar electrode plate such that the electrically insulating tape member does not cover the entire surface area of the conductive flat-plate. The electrically conducting perimeter enables bi-directional uniform current flow through the conductive flat-plate between the terminal connector and the terminal bipolar electrode plate. Also provided is a battery frame member for a static rechargeable battery comprising a liquid diversion system; a gutter; a sealing member; a gas channel; and a ventilation hole. Also provided is a static rechargeable electrochemical battery comprising a pair of terminal assemblies, at least one bipolar electrode interposed between the pair of terminal assemblies, and a battery frame member.

An electrolyte of a redox flow battery, including a negative electrolyte and a positive electrolyte, is provided. The negative electrolyte includes a negative active material and a negative solvent, and the positive electrolyte includes a positive active material and a positive solvent. An initial volume of the negative electrolyte is greater than an initial volume of the positive electrolyte. A redox flow battery including the electrolyte is also provided.