Danionics A/s

Other

Steen Yde-Andersen

Ningling Rao

Asa Wendsjo

Marine Consigny

ANGsa Wendsjo

Pascal Ge

Jens Lindbjerg

Martin Topsoe

Ilmari Katva

Torben Paarup Andersen

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 (T) and which is capable of forming a gel on subsequent cooling following heating to a second temperature (T). Tbeing lower than T, which method comprises: (a) heating the electrolyte precursor to T; (b) optionally cooling the electrolyte precursor, (c) incorporating the electrolyte precursor into the electrochemical cell; (d) heating the electrochemical cell to T; (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.

Method of making polymer electrolyte electrochemical cells

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.

Wound electrochemical cell, a method for the manufacture thereof, and use of such electrochemical cells

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.

Lithium salt/carbonate electrolyte system, a method for the preparation thereof, the use thereof and a battery containing the electrolyte system

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&deg; 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.

Preparation of modified cokes and/or blacks

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. The invention also relates to a gravure roll and a primer-coated current collector foil for use in the method, a primer paste for the production of primer-coated current collector foils and an electrode paste for the production of electrode/current collector laminates.

Electrode/current collector, laminates for an electrochemical device

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. The electrolyte is also electrochemically stable.

Lithium secondary battery

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 L,-value of at least 300 nm and/or an L,-value in the range 50-150 nm and an L,-L,-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.

Lithium secondary battery with flake graphite negative electrode

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.

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Odense, Denmark

Steen Yde-Andersen