Bell Communications Research, Inc.

Caroline N Schmutz

Antoni S Gozdz

Paul C Warren

Jean-Marie Tarascon

Frough K Shokoohi

A flexible polymeric film useful as an interelectrode separator or electrolyte member in electrolytic devices, such as rechargeable batteries, comprises a copolymer of vinylidene fluoride with 8 to 25% hexafluoropropylene. The film may be cast or formed as a self-supporting layer retaining about 20% to 70% of a high-boiling solvent plasticizer or plasticizer mixture comprising such solvents as ethylene carbonate, propylene carbonate, dimethyl carbonate, and dibutyl phthalate. The film may be used in such form or after extracting of the retained plasticizer with a film-inert low-boiling solvent to provide a separator member into which a solution of electrolytic salt is subsequently imbibed to displace retained plasticizer or replace plasticizer previously extracted from the polymeric matrix.

Method of making polymeric electrolytic cell separator membrane

A perforate current collector element (21) embedded within at least one of its polymeric intercalation electrodes (23) reduces the internal resistance of a flexible rechargeable lithium-ion battery (20).

Low resistance rechargeable lithium-ion battery

A hybrid polymeric matrix composition for a lithium-ion rechargeable battery comprises a copolymer of vinylidene fluoride with about 8 to 20% by weight chlorotrifluoroethylene.

Hybrid lithium-ion battery polymer matrix compositions

A rechargeable battery comprises a laminate electrolytic cell in which a flexible plasticized polymer hybrid electrolyte/separator layer is interposed between positive and negative electrode layers of lithium-ion intercalating polymeric matrix compositions bearing respective current collector foils. An elongate laminar cell is formed into a unified battery by means of an initial transverse fold disposing one electrode/collector within the structure and with subsequent sequential folds spiralling the cell, without need for interposed insulation, outwardly toward the electrode ends where the collectors accommodate battery terminals. Immersion of the structure in a solvent extracts the polymer plasticizer which is subsequently replaced by contact with lithium salt solution electrolyte to activate the battery.

Rechargeable battery structure and method of making same

The present invention is a method of fabricating a rechargeable battery structure by extracting plasticizer from plastic battery preforms to render them insensitive to water while maintaining the homogeneous characteristics of the plastic materials to allow subsequent activation of the batteries through the introduction of an electrolyte solution. These battery preforms need not be maintained under anhydrous conditions and can be activated immediately preceding use thereof.

Lithium secondary battery extraction method

A rechargeable lithium ion battery comprises a plurality of interleaved flexible electrolytic cells, each of which is a unitary planar laminated structure comprising polymeric anode, cathode, and intermediate electrolyte layers disposed between electrically conductive anode and cathode collector foil elements. One of the collector foils of a cell has an open grid structure to allow penetration of electrolyte solution into the cell layer while the other is substantially more continuous to provide supporting strength to the cell. At least a pair of cells having respective continuous foil anode and cathode collectors are interleaved in spiral-folded fashion to present those collector foils at the outer surface of the resulting structure to provide terminal contacts for the resulting high-capacity, low-profile battery.

Rechargeable lithium battery construction

Li-ion rechargeable battery cell electrode and electrolyte/separator elements formulated as layers of plasticized polymeric matrix compositions are laminated with electrically conductive collector elements to form a unitary battery cell structure. Adhesion between the electrode and collector elements is enhanced by pretreatment of the collector elements in which a 0.25% to 3.0% solution of a polymeric material compatible with said matrix polymer is applied to a collector foil or grid and dried to form a coated film, and the resulting coated collector element is heated within the range of about 250.degree. to 450.degree. C. for about 5 to 60 seconds.

Method of making a laminated lithium-ion rechargeable battery cell

Li-ion rechargeable battery cell electrode and electrolyte/separator elements formulated as layers of plasticized polymeric matrix compositions are laminated to form a unitary battery cell structure. The structure may be stored indefinitely, since it is essentially devoid of electrolyte solution which typically comprises a moisture-sensitive lithium salt. Prior to the battery's being put into service, at least a portion of the compatible polymeric composition plasticizer is displaced by contact with a lithium salt electrolyte solution or is removed by extraction with a selective solvent and replaced with the electrolyte solution by simple imbibition. The battery thus activated may then be charged and recharged in the usual manner.

Method of making an electrolyte activatable lithium-ion rechargeable

A polymeric film useful as an interelectrode separator or electrolyte member in electrolytic devices, such as rechargeable batteries, comprises a copolymer of vinylidene fluoride and hexafluoropropylene, a medium to high-boiling plasticizer, and a finely divided inorganic filler which has been subjected to actinic radiation or thermal energy to cause crosslinking thereof in the presence of a crosslinking agent selected from the group consisting of an acrylate ester, di- or triallyl ester and a di- or triglycidyl ether.

Crosslinked hybrid electrolyte film and methods of making and using the

A flexible polymeric film useful as an interelectrode separator or electrolyte member in electrolytic devices, such as rechargeable batteries, comprises a copolymer of vinylidene fluoride with 8 to 25% hexafluoropropylene. The film may be cast or formed as a self-supporting layer retaining about 20% to 70% of a high-boiling solvent or solvent mixture comprising such solvents as ethylene carbonate, propylene carbonate, dimethyl carbonate, and dibutyl phthalate. The film may be used in such form or after leaching of the retained solvent with a film-inert low-boiling solvent to provide a separator member into which a solution of electrolytic salt is subsequently imbibed to displace retained solvent or replace solvent previously leached from the polymeric matrix.

Polymeric electrolytic cell separator membrane

A rechargeable battery comprises lithium intercalation compound electrodes and an interposed electrolyte of flexible polymer containing a lithium salt dissolved in a polymer-compatible solvent. Preferred components include tertiary lithium manganese oxide compound positive electrodes, carbon negative electrodes, and poly(vinylidene fluoride) copolymer electrolyte layers containing about 20 to 70% of a solution of lithium salt in a medium boiling solvent comprising such solvents as ethylene carbonate, propylene carbonate, and dimethyl carbonate. The electrolyte layers may be employed in the form of individual separator films or as a coated component of multilayer battery structures to provide electrical ionic conductivity up to about 10.sup.-3 S/cm.

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Eatontown, NJ, United States of America

Caroline N Schmutz