Abstract: A process for producing oxygen-consuming electrodes, in particular for use in chloralkali electrolysis, which display good transport capability and storage capability. In the process, a silver oxide-containing sheet-like structure as intermediate is electrochemically reduced. Also disclosed are methods of using these electrodes in chloralkali electrolysis or fuel cell technology or in metal-air batteries, and the fuel cells and metal-air batteries produced.

Abstract: The present invention relates to an oxygen-consuming electrode comprising a support in the form of a sheet-like structure and a coating comprising a gas diffusion layer and a catalytically active component, wherein the support is based on a material which can be at least partly removed by dissolution, decomposition, melting and/or vaporization. Furthermore, the use of this oxygen-consuming electrode in chloralkali electrolysis or fuel cell technology is described.

Abstract: The present invention relates to a process for producing high purity lithium hydroxide monohydrate, comprising following steps: concentrating a lithium containing brine; purifying the brine to remove or to reduce the concentrations of ions other than lithium; adjusting the pH of the brine to about 10.5 to 11 to further remove cations other than lithium, if necessary; neutralizing the brine with acid; purifying the brine to reduce the total concentration of calcium and magnesium to less than 150 ppb via ion exchange; electrolyzing the brine to generate a lithium hydroxide solution containing less than 150 ppb total calcium and magnesium, with chlorine and hydrogen gas as byproducts; producing hydrochloric acid via combustion of the chlorine gas with excess hydrogen and subsequent scrubbing of the resultant gas stream with purified water, if elected to do so; and concentrating and crystallizing the lithium hydroxide solution to produce lithium hydroxide monohydrate crystals.

Abstract: The present invention relates to an electrocatalytic coating and an electrode having the coating thereon, wherein the coating is a mixed metal oxide coating, preferably platinum group metal oxides, with or without low levels of valve metal oxides. The electrocatalytic coating can be used especially as an anode component of an electrolysis cell and in particular a cell for the electrolysis of aqueous chlor-alkali solutions.

Abstract: The present invention pertains to electrolytic diaphragm cells, particularly for the electrolysis of brine to produce chlorine and caustic. The innovation resides generally in the discovery that electrolytic cell operation can be desirably enhanced by compressing the diaphragm between anode and cathode. This compression of the diaphragm reduces the diaphragm thickness from an original thickness, e.g., from an original thickness of a diaphragm freshly deposited on a cathode. The reduced thickness of the diaphragm provides for cell operation that is less than zero gap operation. By maintaining the diaphragm under compression and in a reduced thickness, the cell operates with a narrower interelectrode gap and consequently at a desirably reduced cell voltage.

Abstract: Disclosed is a method of reactivating a deactivated anode that has a coating of a noble metal or noble metal oxide on a substrate. A coating of a noble metal is deposited on the anode electrolessly. The noble metal in the deposited coating can be platinum, palladium, iridium, rhodium, ruthenium, osmium, or a mixture thereof.

Abstract: In removal of sulfate groups and chlorate groups from brine used for electrolysis, concentrated brine used in an electrolysis process or dilute brine whose concentration is decreased by electrolysis is fed to an anode chamber divided by a cation exchange membrane in a brine treating electrolyzer, where the concentrated or dilute brine is electrolyzed to recover chloride ions therein. The concentrated brine is electrolyzed at a rate of decomposition of salt higher than that in the ion exchange membrane electrolysis process of brine. Thereafter, the concentrated or dilute brine is discharged out of the electrolysis process.

Abstract: The invention discloses a novel structure for an expandable anode to be used in diaphragm cells. This new structure comprises a conductor bar in the form of a copper core provided with a titanium layer having a first and a second pair of flexible expanders fixed thereto. The welding points of the second pair of expanders are positioned orthogonally with respect to the welding points of the first pair of expanders along the circumference of the conductor bar. Also the anode surfaces are connected by welding points to the pairs of expanders. The anode of the invention may be both a new anode and a conventional existing anode having only a first pair of expanders whereto the second pair of expanders is attached. With the device of the present invention the ohmic drop between the conductor bar and the anode surface is substantially decreased and further there is no risk of damaging the interface between the copper core and the titanium coating by an excessive thermal stress, due to the welding procedures.

Abstract: Disclosed is a method of reactivating a deactivated anode that has a coating of a noble metal or noble metal oxide on a substrate. A coating of a noble metal is deposited on the anode either electrolessly or electrolytically. The noble metal in the deposited coating can be platinum, palladium, iridium, rhodium, ruthenium, osmium, or a mixture thereof.

Abstract: The invention includes an electrolytic cell for gas-developing or gas-consuming electrolytic reactions and processes, and an electrolysis process therefor. According to the invention, the capillary slit electrode has conduits enabling the separate flow of reaction gas and electrolyte/permeate in the electrode. The electrode is preferably hydrophilic in a narrow internal region for mounting on a separator, while elsewhere it is hydrophobic. Thus electrolyte/permeate penetrates only into the region of the capillary slit electrode near the separator, while the region away from the separator remains free of electrolyte/permeate, so facilitating the unimpeded flow of the reaction gas. The invention is applicable especially in electrolytic cells for chlor-alkali or hydrogen electrolysis, and in the construction of cells for the generation of power.

Abstract: An electrode comprising a first plate (4) having an active electrode surface and a second plate (14) facing and spaced from the first plate, and at least one barrier plate (13) positioned between the first and second plates and spaced from the active electrode surface of the first plate and from the facing surface of the second plate. An electrolytic cell comprising such an electrode and the use thereof in the electrolysis of aqueous alkali metal chlorides.

Abstract: A method for brine electrolysis using a gas electrode and an electrolytic cell therefor, in which gas electrode 31 permeable to gas and liquid is arranged in cathode chamber 24 in contact with ion-exchange membrane 22. Sodium hydroxide produced on electrode substance 30 of gas electrode 31 easily penetrates the gas electrode and is recovered from the cathode chamber. No sodium hydroxide is produced within the ion-exchange membrane so that penetration of sodium hydroxide into the anode chamber is thereby prevented.