Abstract: The invention relates to a method for the preparation of a polymer electrolyte electrochemical cell using an electrolyte precursor, said precursor comprising one or more solvents, one or more salts and a polymer which dissolves in the solvent at a first temperature (Tdissol) and which is capable of forming a gel on subsequent cooling following heating to a second temperature (Tgel). Tdissol being lower than Tgel, which method comprises: (a) heating the electrolyte precursor to Tdissol; (b) optionally cooling the electrolyte precursor, (c) incorporating the electrolyte precursor into the electrochemical cell; (d) heating the electrochemical cell to Tgel; (e) cooling the polymer electrochemical cell to ambient temperature to bring about gelling of the polymer electrolyte. Preferably the polymer is a homopolymer or copolymer from the group of monomers of vinyl fluoride, vinylidenefluoride, trifluoroethylene, tetrafluoroethylene and hexafluoropropylene.

Abstract: The application describes a cell unit which includes at least two flat electrochemical cells (1′, 1″, 1′″) and a circuit board (5), the cells being folded onto one or both sides of the circuit board whereby the circuitry on the circuit board is protected. Preferably, the cells and the circuit board have the same lengths and widths. The cells may be provided on two or more edges of the circuit board and optionally two cells are connected at the same edges on the board.

Abstract: The invention relates to a rechargeable electrochemical cell comprising a negative electrode, an electrolyte and a positive electrode in which the positive electrode structure comprises a lithium cobalt manganese oxide of the composition Li2CoyMn2−yO4 where 0<y<0.6. The lithium cobalt manganese oxide of the above formula can be the only active compound or can be used together with one or more other rechargeable compounds. The lithium cobalt manganese oxide of the above formula may be in air and moisture insensitive tetragonal form and provides additional active lithium to compensate for capacity losses in lithium ion cells and lithium-alloy cells.

Abstract: The invention relates to a rechargeable electrochemical cell comprising a negative electrode, an electrolyte and a positive electrode, characterized in that the positive electrode structure thereof comprises (a) one or more materials selected from the group consisting of LiMn2O4, LiCoO2, LiNiO2, LiNixCo1−xO2 where 0<x<1, preferably LiMn2O4 and (b) one or more materials selected from the group consisting of orthorhombic LiMnO2, monoclinic LiMnO2 (m-LiMnO2), hexagonal LiFeO2 (h-LiFeO2), &agr;-NaMnO2, &bgr;-NaMnO2, &agr;-NaFeO2, and lithium/sodium compounds of the formula LixNayM(II)O1+1/2(x+y), where x≧0, y≧0 and x+y≦2, and where M(II) is a transition metal in oxidation state +2, selected from the group consisting of Mn, Co, Ni and Fe, preferably LixNayMn(II)O1+1/2(x+y), where x≧0, y≧0 and x+y≦2, more preferably LiNa0.6MnO1.

Abstract: The present invention relates to an electrochemical cell composed of a laminate of two electrode structures in the form of current collectors coated with electrode material interposed electrolyte structures. The laminate is wound in a coil, and in at least the initial turn and the final turn, one of the current collectors has a protruding part extending beyond at least one of the edges of the other current collector in the same turn and in the following or previous turn, respectively, and the first current collector has a protruding part extending beyond one of the edges of the second collector foil, the protruding parts of the current collectors along the first and the second edge, respectively, of the laminate are sealed to each other optionally with interposed insulating polymer material.

Abstract: Modified cokes or blacks suitable as alkali metal intercalation electrodes in electrochemical cells are produced by a method comprising boiling the coke or black in concentrated hydrochloric acid, flushing with distilled water, sonicating the coke or black in acetone, and drying the coke or black at a temperature of 150 to 300° C. The modified cokes and blacks produced by this method show Intercalation capacities up to 50% higher than unmodified cokes and blacks, and maintain the high electrolyte compatibility, rate capability and cyclability of the cokes or blacks.

Abstract: The instant invention is to an electrolyte consisting essentially of a salt mixture and a solvent mixture. The solvent mixture consists essentially of ethylene carbonate and dimethyl carbonate and the salt mixture consists of 60-90% lithium tetrafluoroborate and 10-40% lithium hexafluorophosphate. A battery comprising this electrolyte and a method of preparing this electrolyte are exhibited.

Abstract: A double layer capacitor and a method for producing the same wherein the double layer capacitor comprises a conductive coating based on binders of the melamine resin type such that the conductive coating is present at the interfaces between the current collectors and the electrodes. The double layer capacitor thus produced has good mechanical and chemical integrity and flexibility and is suitable for use in combination with batteries.

Abstract: The invention relates to a cheap and fast method for the production of electrode/current collector laminates, the electrode layer having a thickness of at least 20 &mgr;m. The current collector foil is provided with an electrode paste coating on at least one of its sides by filling paste into the cells or grooves of a patterned matrice roll; transferring paste from the matrice roll onto the current collector foil by a printing operation involving contacting the matrice roll and the current collector foil or alternatively contacting the matrice roll with an offset roll which in turn is in contact with the current collector foil; drying the layer of paste printed onto the current collector; and optionally repeating the process until the desired thickness of the electrode layer is obtained.

Abstract: A lithium secondary battery with an electrolyte containing one or more alkai metal salts, one or more non-aqueous solvents and immobilized by a polymer selected from cellulose acetates, cellulose acetate butyrates, cellulose acetate propionates, polyvinylidene fluoride-hexafluoropropylenes and polyvinylpyrrolidone-vinyl acetates, the polymer preferably being used in an amount of at most 15% by weight based on the weight of the salts, solvents and polymer of the electrolyte system, with the proviso that in the case of polyvinlidene fluoride-hexafluoropropylenes, the polymer is present in an amount of at most 12% by weight based on the weight of the salts, solvents and polymer of the electrolyte system. The immobilized electrolyte does not cause problems with respect to leakage from the cell compartment and the elctrolyte also high conductivity implying a capacity utilization more closely approaching the utilization observed for batteries using liquid electrolyte.

Abstract: A lithium secondary battery has a negative electrode structure, an electrolyte and a positive cathode structure, the negative electrode structure being of at least 40% by weight of natural flake graphite, having an La-value of at least 300 nm and/or an Lc-value in the range 50-150 nm and an La-Lc-ratio of at least 2, and the electrolyte having at least 10% by weight of propylene carbonate based on the weight of the solvent and salts of the electrolyte system. Natural flake graphite is compatible with propylene carbonate containing electrolytes, thereby forming stable battery configurations.

Abstract: Disclosed herein is a high voltage electrochromic device comprising a number of electrodes, a non-aqueous electrolyte system, said system comprising one or more alkali and/or ammonium salts and a solvent in the form of one or more ortho-, meta- or para-phthalates. Also disclosed is a method for producing said electrochromic devices and the use of phthalate based electrolyte systems in electrochromic devices.

Abstract: A new non-aqueous electrolyte system for use in batteries, capacitors and electrochromic displays, and consisting essentially of an alkali or ammonium salt, a solvent mixture, and optionally a polymer is disclosed. The new system is characterized in that the solvent mixture comprises a mixture of ethylene carbonate (EC) and -valerolactone (-VL), optionally containing one or more additional solvents selected from other organic carbonates, other lactones, esters and glymes, said system optionally being confined a separator. The electrolyte system can be applied in a broad voltage range, has a conductivity higher than 10.sup.-3 S/cm at room temperature, and shows a high stability against reduction. The improved stability towards reduction is mirrored in a cycling efficiency which is superior to the cycling efficiency of known non-aqueous electrolyte systems.

Abstract: A new method for synthesising an essentially V.sub.2 O.sub.5 -free vanadium oxide having a mean vanadium oxidation state of at least +4 but lower than +5 from NH.sub.4 VO.sub.3 is disclosed. By this method NH.sub.4 VO.sub.3 is heated to a reaction temperature sufficient for thermal decomposition of NH.sub.4 VO.sub.3, and at said reaction temperature, the pressure is kept on at least 0.5 MPa. The method enables production of single-phase V.sub.6 O.sub.13, single-phase VO.sub.2 as well as any mixture thereof in a remarkably simple manner, as it primarily involves careful control of temperature and pressure conditions. The synthesis method of the invention can thus be easily scaled up to any industrial requirement.

Abstract: A process is disclosed for the preparation of lithium secondary battery cathode active materials which are of the form Li.sub.y Mn.sub.2-z M.sub.2 O.sub.4 where M is selected from the group consisting of Co, Ni, Ti, V and Fe, y is in the range from 0 to 1.5 and z is in the range from 0 to 1. The process comprises forming a melt or saturated solution from manganese acetate, lithium hydroxide and water, keeping the melt/solution at a temperature in the range of 70 to 110.degree. C. for a period of from 10 minutes to 4 hours under stirring so as to form an essentially homogeneous material, and drying said material followed by calcination at a temperature in the range of 300 to 800.degree. C.