Abstract: A process for electrowinning metal in a low temperature melt is disclosed. The process utilizes an inert anode for the production of metal such as aluminum using low surface area anodes at high current densities.

Abstract: The present invention relates to a method to produce a thin film three dimensional microelectrode of an electrically conductive polymer having an organized array of identical microprotrusions, which method comprises:(a) depositing at least one conductive metal thin film on an essentially smooth substrate,(b) depositing a thin film of a micropositive photoresist on the surface of the at least one conductive metal thin film,(c) subjecting the combination of step (b) to photolithographic or electron beam lithographic conditions with a mask capable of producing a metallic microwell,(d) electrochemically polymerizing an electrically conductive polymer onto the conducting metal,(e) removing the photoresist to produce the three dimensional microelectrode array of the electrically conductive polymer. Preferred electrically conductive polymers of step (d) are selected from polypyrrole or polyaniline.

Abstract: An electrochemical electrode, comprising carbon particles distributed in porous, inorganic ceramic material produced by sol-gel technology, wherein the particles form a continuous network which enables conductivity throughout the sol-gel derived matrices.

Abstract: A non-aqueous electrolyte secondary battery has a negative electrode, a positive electrode and a non-aqueous electrolyte with lithium ion conductivity. A composite oxide produced from a metal or a metalloid and lithium represented by composition formula Li.sub.x MO (where M represents metals or metalloids other than alkali metals, and x satisifies 0.ltoreq.x) is used as an active material of one or both of the negative electrode and the positive electrode. The battery exhibits a large charging/discharging capacity and a high energy density together with smaller polarization (internal resistance) on charging and discharging which facilitates a large current charging and discharging with a long cycle life and reduces deterioration due to excess charging and excess discharging.

Abstract: A biosensor system using flow injection analysis (FIA) for the analysis of glucose in human serum. The system utilizes a sensor in which the enzyme glucose oxidase (GOD) is incorporated into graphite paste modified with tetracyanoquinodimethane (TCNQ). TCNQ acts as an efficient mediator for oxidation of the reduced enzyme at 200 mV vs Ag/AgCl. The sensor provides a linear response to glucose over a wide concentration range. The flow injection analysis system has a detection limit of 200 nmol glucose using a 100 .mu.l sample and as been demonstrated to be stable after 800 consecutive sample injections.

Abstract: To improve its resistance to penetration and degradation by sodium, a carbon cathode for use in aluminium production by the electrolysis of alumina dissolved in a cryolite-based molten electrolyte is pre-treated with a solution, suspension or melt of a compound of lithium, sodium and/or potassium. This pre-treatment takes place prior to, during or after forming the cathode but before use thereof. The entire carbon cathode, or only that part of the carbon which is nearest to the active cathode surface is treated, making it more resistant to penetration by components of the molten electrolyte of aluminium.

Abstract: A method of producing a component of an aluminium production cell made of a carbon-based composite material containing a refractory hard metal boride, carbide, oxide, nitride or combinations or mixtures thereof and aluminium as metal, alloy or as an aluminium compound, comprises firstly providing a reaction mixture of aluminium and precursors which react to form the refractory hard metal compound, and optional fillers and additives. The reaction mixture is mixed with particulate carbon in an amount of from 1 to 20 parts by weight of carbon for 1 part by weight of the reaction mixture; and with a colloidal binder containing at least one of colloidal silica, alumina, yttria, ceria, thoria, zirconia, magnesia, lithia, in an amount to fully wet the carbon particles. The resulting mixture is compacted and dried and heated to initiate reaction of the reaction mixture by self-propagating micropyretic reaction.

Abstract: A thermocell includes a negative electrode, such as a lead-acid electrode, and a porous oxygen (air) electrode disposed in a housing and separated by a separator. During discharge, oxygen is allowed to permeate through the oxygen electrode and separator to reach the negative electrode. Chemical oxidation of the negative electrode by oxygen in the presence of sulfuric acid yields water, lead sulfate, and heat. The heat can be used in many ways, such as warming up an adjoining automotive battery in winter, or as a personal heating pad. The heating rate is controlled by the rate of oxygen ingress. When not in use, the oxygen electrode is sealed by taping or by other means to stop ingress of oxygen. The used thermocell can be recharged by charging the negative electrode while evolving oxygen at the oxygen electrode.

Abstract: An improved electrochemical detection cell comprising a palladium reference electrode.

Abstract: Disclosed is an electrochemical reactor for partially oxidizing methane and cogenerating electrical energy. A solid-state ionic reactor is described in which a solid electrolyte is provided with a cathode and a perovskite type anode having a wide range of oxygen nonstoichiometry. The cell generates electrical energy as a result of the chemical potential difference brought about by the catalytic oxidation of methane at the anode with oxygen that chemically diffuses from the cathode through the solid-state ionic conductor.

Abstract: A hydrogen-occlusion electrode and a method of manufacturing the electrode are described. The hydrogen-occlusion electrode comprises from about 42-84 vol. % of a hydrogen-occlusion alloy, from about 3-13 vol. % of a bonding material where the volume percent is based on 100% from about 3-15 vol. % of an electroconductive material, and has residual pores in an amount of 10-30 vol. %. The electroconductive material has an average particle size of 1.3 .mu.m or less. The bonding material is preferably polyvinylidene flouride (PVdf). In manufacturing the foregoing hydrogen-occlusion electrode, a formed electrode plate body including PVdF as a bonding material is heat-treated in a vacuum or inert gas atmosphere at a temperature ranging from about 160.degree. C. to about 200.degree. C. An electrode is thereby obtained wherein the alloy particles are prevented from separating from the electrode resulting in an improvement of mechanical strength and electroconductivity in the electrode.

Abstract: The present invention relates to metal anodes for oxygen evolution from solutions containing fluorides or artionic fluorocomplexes such as tetrafluoroborates and hexafluorosilicates, the anodes having a metal substrate or matrix selected in the group comprising nickel-copper alloys with a copper content in the range of 2.5 and 30% by weight, tungsten or tantalum, niobium or titanium, combinations thereof or alloys of the same with palladium, nickel or yttrium. The anodes further comprise electrocatalytic compounds for oxygen evolution dispersed in the metal matrix. In the case of nickel- copper alloys, useful electrocatalytic compounds are cerium or tin dioxides, with suitable additives, while for tungsten, cobalt added with nickel, iron, copper or palladium may be used.

Abstract: An electrolytic ozone generating apparatus comprising a closely adhered electrode structure of(i) an anode composed of an electrically conductive porous material carrying an ozone generating catalyst,(ii) a perfluorocarbonsulfonic acid ion-exchange membrane which is a solid electrolyte, and(iii) a cathode composed of a gas electrode carrying a catalyst, andmeans for supplying an oxygen-containing gas to the cathode side,wherein the gas electrode as the cathode has a hydrophilic property and a hydrophobic property and carries a catalyst unevenly distributed therein at the ion-exchange membrane side, and a process for generating ozone using the apparatus. The electrolysis is conducted while supplying an oxygen-containing gas to the cathode side.

Abstract: An ion conducting device having a plurality of solid electrolyte plates arranged into a stack, each electrolyte plate having electrode material adherent to a significant portion thereof. A plurality of individual spacers are disposed between adjacent electrolyte plates in the stack, each spacer spacing successive electrolyte plates apart, and defining a plurality of chambers in the spaces between adjacent electrolyte plates. The electrode material on the electrolyte plates is electrically connected whereby electrode material on every other successive plate is connected in series, from one end of the stack to the other, whereupon the electrical path wraps around the stack and extends back along the stack and connects in series the electrodes not previously connected.

Abstract: An electrolysis cell provides a plurality of electrode stacks arranged electrically and mechanically back-to-back in a vertical orientation to develop an electrically neutral effluent. The electrode stacks comprise a plurality of electrode plates that seal against an inert housing by seals with a U-shaped cross-section. The cell is fully insulated and provides a series electrolyte flow path.

Abstract: An electrolysis cell for producing metals by electrolytic reduction of molten baths which includes non-consumable inert anodes and refractory hard metal cathode elements. The cathode elements are replaceably mounted in the electrolysis cell and have inclined planar working surfaces which have grooves therein. A method for producing metals by use of the electrolysis cell includes utilizing the grooves to control the release of anode gases.

Abstract: A particulate composition having improved stability in typical electrolytes consisting essentially of Magneli phase substoichiometric titanium oxides.

Abstract: A process for electrowinning metal in a low temperature melt is disclosed. The process utilizes an inert anode for the production of metal such as aluminum using low surface area anodes at high current densities.

Abstract: Process for oxidizing hydroxymethylpyridine derivatives to pyridinecarboxylic acid derivatives at nickel oxide hydroxide anodesA process is described for oxidizing o-hydroxymethylpyridine derivatives into their pyridinecarboxylic acid derivatives at nickel oxide hydroxide anodes.

Abstract: An electrode for use in electrochemical ion exchange comprises an electrically conducting element covered by at least two layers of ion exchange material. The material in one layer differs in its electrical, chemical, or ion exchange properties from that in an adjacent layer. For example a thin layer of cation exchange material underneath a thicker layer of anion exchange material may be used to inhibit the oxidation of chloride ions; a thin layer of cation exchange material covering a thicker layer of anion exchange material provides an anion-responsive electrode with enhanced selectivity for particular ions. An ion-selective anion-responsive electrode can also comprise a thin outer layer of a very weak base anion-responsive material, covering a thicker layer of a strong base material of lower electrical resistivity.

Abstract: The device according to the present invention comprises a galvanic cell including a gas generating electrode, a counter electrode and an aqueous electrolyte enclosed in a housing. The device has one or more openings, by which the generated gas is released to the environment. The device also contains means for electrically connecting said gas generating electrode and said counter electrode and for establishing a current flow between said gas generating electrode and said counter electrode for generating a predetermined quantity of gas by said gas generating electrode for release from said opening of said galvanic cell. The objective of the cell is to generate and release oxygen or hydrogen gas, thereby defining a new type of cell. The device is referred to as a "gas generator cell.

Abstract: An electrode comprising an electrically conductive base, and a selectively permeable membrane which is produced by forming a membrane from a mixed solution comprising (a) albumin, (b) at least one type of crosslinking agent and (c) chitosan. The selectively permeable membrane is useful, e.g., in conjuction with an electrode. An enzyme electrode is also provided having the selectively permeable membrane disposed on the electrode and an immobilized enzyme membrane disposed on the selectively permeable membrane. The immobilized enzyme membrane is prepared by incorporating a carboxylate into the solution containing the enzyme and an aldehyde as the crosslinking agent. The crosslinking is effected by heating or drying.

Abstract: An apparatus for treating a liquid by electrochemical ion exchange comprises a flow channel (34) in which are arranged a cation-responsive ion exchange electrode (38) side by side with an anion-responsive ion exchange electrode (42), with a counter electrode (40,44) between them. By controlling the currents to the two ion exchange electrodes (38,42) independently, the pH of the treated liquid can be controlled at a desired value.

Abstract: The invention is directed to an electrochemical measuring cell for measuring ammonia or hydrazine and includes at least a measuring electrode and a counter electrode in an electrolyte. The measuring cell provides a signal increase having a shorter response time and an improved signal stability. For this purpose, the electrolyte is an aqueous solution of a hygroscopic salt of an alkali metal or earth alkali metal such as calcium nitrate or lithium nitrate or a mixture of both salts.

Abstract: Improved high rate cathode material and method of making same by chemical addition reaction.

Abstract: A dimensionally stable combustion synthesis product of a composition containing at least 20% by weight of a particulate combustible material; at least 15% by weight of a particulate filler material capable of providing desired mechanical and electrical properties; and up to 35% by weight of a particulate inorganic binder having a melting point lower than the combustion synthesis temperature. Electrodes suitable for electrochemical processing are a preferred product form, particularly electrodes for use in the electrowinning of aluminum from its oxide.

Abstract: A membrane-electrode structure for use in an electrochemical cell comprising an ion exchange membrane with a cathode layer and an intermediate layer between the cathode and the membrane. The intermediate layer comprises about 5 to 80% by weight of inorganic solid particles and about 95 to 20% by weight of an ionic conductive polymeric binder.

Abstract: The invention relates to a composition comprising an electrically conductive polymer chosen from polypyrrole and/or substituted polypyrrole, a vanadium compound and an anion.The invention also relates to a process for obtaining this composition and to the uses of this composition.

Abstract: An electrolysis cell for the production of metals is disclosed. Ther cell includes at least one anode that, under the operating conditions of the cell, dissolves into the cell electrolyte to provide a cell feed material. Additionally the anode is fabricated of a material that, under the operating conditions of the cell is electronically conductive as a solid and can provide an ionically conductive medium either when molten or when dissolved in a liuqid.

Abstract: A supported catalyst useful in the preparation of an electrode for an electrochemical cell which comprises the residue remaining after heating at about 500.degree. to about 700.degree. C. a transition metal and a polymer such as polyvinylpyridine all adsorbed on a support material. Useful electrodes are prepared by combining the supported catalyst with a current collector.

Abstract: A metal surface is now described having enhanced adhesion of subsequently applied coatings. The substrate metal of the article, such as a valve metal as represented by titanium, is provided with a highly desirable surface characteristic for subsequent coating application. This can be initiated by selection of a metal of desirable metallurgy and heat history, including prior heat treatment to provide surface grain boundaries which may be most readily etched. In subsequent etching operation, the surface is made to exhibit well defined, three dimensional grains with deep grain boundaries. Subsequently applied coatings, by penetrating into the etched intergranular valleys, are desirably locked onto the metal substrate surface and provide enhanced lifetime even in rugged commercial environments.

Abstract: An electrochemical process and electrolytic cell for manufacturing chlorine-free chlorine dioxide from dilute alkali metal chlorite solutions in a single step is disclosed. The electrolytic cell uses a porous flow-through anode and a cathode separated by a suitable separator.

Abstract: An electrochemical apparatus and method for supplying volatile hydrides of sufficient purity, at the proper pressure, and in the required volume, for direct introduction into a chemical vapor deposition reactor in which semiconductors are manufactured and doped.

Abstract: The invention provides a lithium secondary battery using hydric boron carbonitride which is a layered compound represented by BC.sub.x N.sub.y H.sub.z, where 0.5.ltoreq.x.ltoreq.12, 0.7.ltoreq.y.ltoreq.1.5, and 0.01.ltoreq.z.ltoreq.3, as the active material of the negative electrode. This compound is obtained by a CVD process. The electrolyte is a solution of a lithium salt in an organic solvent. The material of the positive electrode is an oxide such as MnO.sub.2 or V.sub.2 O.sub.5, a sulfide such as MoS.sub.2 or TiS.sub.2 or a conductive organic polymer such as polyaniline. In this secondary battery Li is smoothly intercalated in and released from the hydric boron carbonitride of the negative electrode, and the energy density with respect to the active material of the negative electrode is sufficiently high. This battery bears a fairly large number of charge-discharge cycles.

Abstract: Disclosed herein are processes for preparing a raw material dispersion and raw material powders for producing reaction layers of a gas permeable electrode. The raw materials are prepared in one aspect of the invention by mixing fine particles containing a surface-active agent, freezing the mixture to a temperature the surface-active agent loses at least part of its function and then thawing out the same. The resulting material exhibits superior catalytic performance because the particles are dispersed uniformly by lack of the function of surfaceactive agent at the time of freezing.The raw materials are prepared in another aspect of the invention by mixing hydrophilic minute particles coated with ion exchange resin, PTFE and hydrophobic fine powders.

Abstract: A highly durable, stable electrode having a coating comprised of an oxide of at least one metal selected from nickel and cobalt, which coating additionally contains titanium and zirconium components in proportions of 0.1. to 3.5% in terms of atomic percentage of titanium and 0.1 to 3% in terms of atomic percentage of zirconium, respectively. The electrode can advantageously be used in electrolyses in which hydrogen is evolved on the electrode, such as electrolyses of an alkali metal chloride and water. The electrode advantageously exhibits a low hydrogen overvoltage, enabling electrolysis to be performed stably for a prolonged period of time.

Abstract: An electrode comprising a gas permeable and liquid permeable coating bonded to an ion exchange membrane, said coating comprising low overvoltage electrocatalytic particles, more electroconductive electrolyte resistant particles and an electrolyte resistant binder compatible with the membrane to bond the particles thereto, the electrode coating being provided with a plurality of pores with a pore size of at least 0.1 microns.Effective porosity is imparted to the layer of particles by means of a sacrificial, pore-forming agent and by leaching out such agent after the particles have been bonded together and the layer formed is in its desired thickness, preferably after it has been deposited upon the membrane.Surface resistivity of the layer is reduced and the layer is effectively reinforced by incorporating electroconductive particles which often have a higher overvoltage than the electrocatalytic particles and also have high electroconductivity.

Abstract: Disclosed is a carbon electrode having low polarizability, comprising a porous carbon block and, contained in the pores thereof, a metal fluoride mixture composed of LiF and a metal fluoride other than LiF. This carbon electrode can easily be obtained by a skillful impregnation method. When such a carbon electrode is used as an anode in electrolyzing an electrolyte comprising a mixed molten salt system of potassium fluoride and hydrogen fluoride in an electrolytic cell, polarization of the anode is extremely low and the anode effect is remarkably suppressed so that the electrolysis can stably be performed while exhibiting not only a high anodic current density but also a low voltage.

Abstract: Method and apparatus for electrolytic generation of permanganate. The invention includes a manganese dioxide adherent cathode surface which eliminates undesirable reduction reactions at the cathode during electrolysis thereby increasing permanganate generation efficiency.

Abstract: An electrode comprising: metallic electrode material; and a nonporous solid composite material encapsulating the electrode material, the composite material comprising an inert matrix material having hydrogel substantially uniformly dispersed therein, the hydrogel comprising 10% to approximately 50% by weight of the dry composite material, there being sufficient bonding between molecules of the hydrogel and the matrix material to prevent substantial leach-out of hydrogel molecules from the composite.

Abstract: Dirhodium complexes such as tetrakis (.mu.-2-anilinopyridinato)dirhodium are used in the catalytic reduction of dioxygen. An electric potential is applied to the dirhodium complex either dissolved in solution or supported by an electrode.

Abstract: An electrochemical device (10) capable of generating oxygen from air (23) upon application of an electrical current, is made containing a plurality of adjacent cells (12) and (12') electrically connected in series, where each cell contains optional support (22), inner, porous oxygen electrode (20), dense, solid oxide electrolyte (14) on top of the inner oxygen electrode, and outer, porous air electrode (16) on top of the electrolyte, where dense segments of interconnection material (18) are disposed between cells, the interconnection electrically connecting the outer air electrode from one cell to the inner oxygen electrode from an adjacent cell, where the device contains gas impermeable, dense, contacting segments of electrolyte (14) and interconnection material (18) and can contain two end portions at least one of which provides for oxygen delivery.

Abstract: A process for fabricating a fuel electrode comprising: slurry dipping to form layers which are structurally graded from all or mostly all stabilized zirconia at a first layer, to an outer most layer of substantially all metal powder, such an nickel. Higher performaance fuel electrodes may be achieved if sinter active stabilized zirconia doped for electronic conductivity is used.

Abstract: Metal electrodes provided with a coating consisting essentially of a mixed oxide compound of (i) a compound of the general formula ABO.sub.4, having a structure of the rutile-type, where A is an element in the trivalent state selected from the group consisting of Al, Rh and Cr, and B is an element in the pentavalent state selected from the group consisting of Sb and Ta, (ii) RuO.sub.2 and (iii) TiO.sub.2 ; wherein the mole fraction of ABO.sub.4 is between 0.01 and 0.42, the mole fraction of RuO.sub.2 is between 0.03 and 0.42, and the mole fraction of TiO.sub.2 is between 0.55 and 0.96. The electrodes have low precious metal content, provide improved durability and improved current efficiency-anodic overvoltage performance. They are used in the electrolysis of chloride containing liquors in the production of, for example, chlorine and more particularly, chlorate.

Abstract: An electrode comprising a gas permeable and liquid permeable coating bonded to an ion exchange membrane, said coating comprising low overvoltage electrocatalytic particles, more electroconductive electrolyte resistant particles and an electrolyte resistant binder compatible with the membrane to bond the particles thereto, the electrode coating being provided with a plurality of pores with a pore size of at least 0.1 microns.Effective porosity is imparted to the layer of particles by means of a sacrificial, pore-forming agent and by leaching out such agent after the particles have been bonded together and the layer formed is in its desired thickness, preferably after it has been deposited upon the membrane.Surface resistivity of the layer is reduced and the layer is effectively reinforced by incorporating electroconductive particles which often have a higher overvoltage than the electrocatalytic particles and also have high electroconductivity.

Abstract: An electrode for measuring the activity of ionic species. The electrode comprises a material which is chemically sensitive to at least one ionic species. The material comprises an insulating component and a conductive component of lower resistivity than the insulating component. The insulating component has a density of proton binding sites sufficiently large to be sensitive to the ionic species. The conductive component comprises particles, the size of which are sufficiently small to modify the bulk conductive properties such that the susceptibility of the particles to redox interference in the operation of the electrode is decreased, while maintaining sufficient conductivity to operate in Faradaic electrode configurations. Illustratively, the insulating component is tantalum oxide, zirconium oxide or aluminum oxide and the conductive component is iridium, platinum, ruthenium, palladium, rhodium or osmium oxide.

Abstract: A semiconductor process chamber with electrolytic ceramic cell having one major surface in the chamber. A second major surface of the cell is outside the process chamber. When activated by heat and an electric current between the two major surfaces, the cell selectively removes oxygen from the processing chamber.

Abstract: Finely divided particles of alumina are electrolytically reduced to aluminum in an electrolytic reduction vessel having a plurality of vertically disposed, non-consumable anodes and a plurality of vertically disposed, dimensionally stable cathodes in closely spaced, alternating arrangement with the anodes. A horizontally disposed, gas bubble generator is located at the vessel bottom, underlying the cathodes and the spaces between each pair of adjacent electrodes. The vessel contains a molten electrolyte bath composed of (1) NaF+Alf.sub.3 eutectic, (2) KF+AlF.sub.3 eutectic and (3) LiF. The alumina particles are maintained in suspension in the molten electrolyte bath by rising gas bubbles generated at the anodes and at the gas bubble generator during the reduction process.

Abstract: Renewable composite microelectrodes for electrochemical applications are formed by an initial coating on an elongated conductive substrate of less than 500 micrometers over at least a portion of its length with a modifier composition, and a superposed coating of electronically resistive polymer. The initial coating is exposed only at the tip portion of the microelectrode. The initial coating may be an absorbed layer of the modifier, a homogeneous layer of a polymeric matrix with the modifier dispersed therein, or a layer of a polymer with a modifier in its chain. The modifier provides distinctive properties to the surface of the electrode which may be electroactivity, inclusion, acidic/basic, complexing/chelating or electrocatalysis. The microelectrode will normally be used with only the tip portion thereof immersed in the solution, and it may be renewed by removing the contaminated tip portion.

Abstract: Bonded, coherent fibrous web substrates well adopted as cathodic elements for electrolytic cells and advantageously incorporating an electrocatalytic agent, include a web matrix which comprises a plurality of fibers, at least a portion of which comprising electrically conductive fibers, e.g., carbon fibers, said plurality of fibers being coherently bonded together with a fluorine-containing polymer, and said web substrate having a resistivity of up to about .[.0.4.]. .Iadd.4.0 .Iaddend..OMEGA..cm.