Abstract: A method for measuring the real hot-spot temperature in an electric apparatus containing an oil, such as an electric power transformer. The electric apparatus is operated under predetermined and modifiable operating conditions. This method comprises the use of one or several chemical compounds or tracers present and soluble in the oil. Each tracer may transform, at a given temperature, in order to form a residue, such as a soluble gas. From the presence of the residue in the oil, the operator will be able to determine under which predetermined operating condition the hot-spot has been reached and to deduce the hot-spot for a given condition. Among different used compounds, there are diazoic compounds, carbonyl metals, colorants, pigments, liquid crystals and albumins. The method also allows to check the quality of the apparatus on the market and to estimate its life span.

Abstract: A method for measuring the real hot-spot temperature in an electric apparatus containing an oil, such as an electric power transformer. The electric apparatus is operated under predetermined and modifiable operating conditions. This method comprises the use of one or several chemical compounds or tracers present and soluble in the oil. Each tracer may transform, at a given temperature, in order to form a residue, such as a soluble gas. From the presence of the residue in the oil, the operator will be able to determine under which predetermined operating condition the hot-spot has been reached and to deduce the hot-spot for a given condition. Among different used compounds, there are diazoic compounds, carbonyl metals, colorants, pigments, liquid crystals and albumins. The method also allows to check the quality of the apparatus on the market and to estimate its life span.

Abstract: A process for extruding a thin positive electrode sheet having at least 40%/wt of solid content for a lithium polymer battery through a single or twin screw extruder is disclosed as well as a positive electrode sheet produced therefrom. A mixture of active cathodic intercalation material, lithium salt and electronic conductive material is mixed with a polymer of the polyether family in a ratio of at least 40% of total weight into the mixing chamber of an extrusion machine and extruded through a classical sheet die into a thin cathode sheet or film onto a substrate in sheet form.

Abstract: Polymer electrolyte compositions for lithium electrochemical generators of the LPB type (lithium polymer electrolyte battery), comprising a mixture of polymers wherein one of the components has a high molecular weight, such as those used currently in LPB batteries, and wherein the other component is a low molecular weight polymer resulting in a more efficient and faster multi-dimensional cross-linking by irradiation, so as to give a network which is interpenetrated or not and films of electrolyte being have better mechanical properties and lower thicknesses, while preserving the good properties of adhesion on the electrodes and the choice of the coating techniques.

Abstract: Preparation of an electrolyte film for lithium/polymer electrolyte batteries by extruding a powder mixture containing a polymer, a lithium salt and an additive consisting of an ultra fine powder of a metal oxide, such as silica, aluminum, or titanium oxide with a particle size between about 7 and 40 nm. The role of the additive is to prevent the formation of adhesive solid blocks in the powder mixture and to allow the introduction of this mixture in the extruder. Electrolyte compositions, electrolytes as well as electrochemical generators obtained according to the invention are also described.

Abstract: Before laminating the electrolyte with the positive electrode, the electrolyte is heated at a temperature higher than its softening temperature or the melting temperature of its crystallites, and the heated electrolyte is allowed to return to room temperature before laminating the positive electrode to the electrolyte at room temperature. This enables to prevent the formation of wrinkles on the collector of the positive electrode.

Abstract: To prepare polymer dispersions containing large quantities of solid particles, with at least some of these consisting of materials with a high specific area (>50 m.sup.2 /g) or oil absorption capacity, the mixture of particles is first co-ground in a non polar solvent. The co-ground mixture is dried until obtaining a dry powder of reagglomerated particles, which is dispersed in a solution containing a polymer and possibly a salt. Large quantities of solid particles can thus be dispersed while maintaining adequate rheological properties for the dispersion, and low porosities and few surface defects in the films obtained by coating the dispersion. This process can be used to prepare thin films of positive electrode for lithium polymer batteries, as well as in the paint, coatings and magnetic tape industry.

Abstract: Preparation of an electrolyte film for lithium/polymer electrolyte batteries by extruding a powder mixture containing a polymer, a lithium salt and an additive consisting of an ultra fine powder of a metal oxide, such as silica, aluminum, or titanium oxide with a particle size between about 7 and 40 nm. The role of the additive is to prevent the formation of adhesive solid blocks in the powder mixture and to allow the introduction of this mixture in the extruder. Electrolyte compositions, electrolytes as well as electrochemical generators obtained according to the invention are also described.

Abstract: A solvent of the polymer-salt complex and a non-solvent thereof are added to the solvent used in the polymer synthesis, to provide a lower and an upper phase. The lower phase contains substantially all the polymer in the solvent of the polymer-salt complex. It is separated from the upper phase and the salt is added to the lower phase to constitute a solution of the electrolyte.

Abstract: Peeling of an LPB amorphous electrolyte from its coating substrate or protective film is carried out by introducing a non-polar solvent, based on at least one aliphatic or cycloaliphatic hydrocarbon containing about 5 to 15 carbon atoms, between the electrolyte and its substrate or protective film. It is thus possible to suddenly and easily separate the substrate or the protective film from the electrolyte without pulling off any amount thereof.

Abstract: In an electrochemical cell consisting of a superposition by lamination of positive and negative electrodes, a solid polymer electrolyte as well as a metallic collector in which the negative electrode and collector layers are slightly offset with respect to each other so as to permit lateral current collection, a band of insulating material is inserted so as to prevent the free edge of the collector facing the layer of electrolyte and/or the negative electrode layer from cutting through the electrolyte layer and/or thereby short-circuiting the two electrodes. The disclosure also describes the preparation of such an electrochemical cell.

Abstract: Polymer based amorphous compositions are melt extruded in the form of thin films, directly on the positive electrode of an all solid lithium battery. This procedure has many advantages as compared to the procedure using a solvent (rapidity, cost, quality of the interface, no problems with recycling and environment).

Abstract: Two metallic foils each have a continuous band of polyethylene film adhesively bonded thereto. The lithium battery is sandwiched between these two metallic foils and a thermo-seal is provided to join the two polyethylene films. This construction prevents any outside substance from contacting the lithium battery.

Abstract: The invention concerns a process for manufacturing a double-layer electrolyte/electrode electrochemical sub-assembly comprising a positive composite electrode layer and a superimposed electrolyte layer, said layers each containing an ionically-conducting macromolecular material and having at their interface a physical and chemical continuum between the macromolecular material of the electrolyte and that of the electrode, and the sub-assembly so obtained. The process consists in depositing one of the layers on a support from a fluid phase containing the constituents of this layer, partially cross-linking the layer, and then spreading the other layer on this partially cross-linked layer from a fluid phase containing the constituents of the other layer and capable of dissolving the macromolecular material of the first layer deposited on the support. Application of the double-layer sub-assembly to the fabrication of electrochemical cells in the form of thin layers.

Abstract: The water and microwave permeable dielectric insulation in an electrotechnical high voltage equipment is dried by means of microwaves. The electrotechnical equipment has a central conductor on which the insulation is wrapped, and it is disposed within an electrically conducting hollow cylinder with its central conductor coaxial with the latter cylinder to form a coaxial, microwave transmission line. Microwaves are propagated through the coaxial transmission line to heat the water in the dielectric insulation, to transform it into water vapor, and to thereby dry the insulation. The microwave transmission line is air-tight and the water vapor is evacuated through a vacuum pump or cold trap.

Abstract: A solid polymeric electrolyte comprises a macromolecular material in which there is dissolved an ionic compound, particularly an ionic compound in solution in a copolymer of ethylene oxide and a second unit selected so that the copolymer chain maintains a polyether characteristic. Also a high performance composite electrode embodying this electrolyte, and a process for obtaining this electrolyte.

Abstract: The present invention relates to novel macromolecular materials constituted by a salt in solution in a copolymer of ethylene oxide and of a second monomeric unit the structure of which preserves on the chain a polyether structure.The application of the invention is particularly useful in the realization of composite electrodes and electrolyte of primary or secondary electrochemical generators, thus necessitating the excellent conductivities of these materials.