Bell Communications Research, Inc.

Bell Telephone Laboratories

Telcordia Technologies, Inc.

Valence Technology, Inc.

Paul C Warren

Antoni S Gozdz

Caroline N Schmutz

Jean-Marie Tarascon

Frough K Shokoohi

Glen G Neuburger

Jean Marie Tarascon

Single cell laminated polymeric rechargeable battery sheets are folded in irregularly alternating directions about parallel fold axes to provide battery cell structures presenting available terminal locations requiring reduced collector element current travel distance to thereby significantly reduce battery impedance. An embodiment enables the use of equilateral cell sheets which are folded about orthogonal axes in two dimensions to yield battery cells with exceptionally high ratios of active area to collector-origin impedance.

Low impedance folded polymeric laminate rechargeable battery and method of making

The dangers of short-circuiting and lithium metal plating during recharging of a unitary laminate lithium-ion intercalation battery cell are alleviated by trimming the periphery of the cell with a transverse slicing cut made at an angle from the perpendicular of the major plane surface of the cell. The resulting angled peripheral edges of the cell provides greater edge separation between electrode layers and reduces the occurrence of metal-plating accumulation of lithium ions at the edge surface of the negative electrode.

Method of making laminated polymeric rechargeable battery cells

Formation of a unitary laminate rechargeable battery comprising electrode and separator/electrolyte elements of polymer composition utilizes apparatus comprising compression rollers of sufficient hardness to resist deformation during laminating contact with such elements. Maximum progressive compression short of lateral deformation of battery elements ensures expulsion of interfacial entrapments and optimum functional contact between laminate elements. Battery structures fabricated with the apparatus may comprise active particulate component ratios in excess of about 75% by weight.

Method for making laminated rechargeable battery cells

A coating of a vinylidene fluoride polymer on a metal foil is heated at about 350.degree. C. to 450.degree. C. in a non-oxidizing atmosphere of inert gas to provide a rechargeable battery current collector having an exceptional bonding surface which maintains a long-lasting and highly-conductive laminate interface with an associated polymeric battery electrode composition.

Treatment for improved conductivity of collector-electrode interface in

Electrical connection is maintained between an electrical conductor element (32) and a fragile expanded-metal grid current collector element (12) of a flexible laminate structure rechargeable battery (10) by means of thermally-activated adhesive sheet material (34) which provides physical reinforcement as well as maintaining stable electrically-conductive contact between the elements, Such adhesive materials comprising a metal foil surface (46) may also provide direct electrical connection between current collector or battery electrode elements and external utilization devices.

Electrical connection for a polymeric laminate battery structure

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

An electrically-conductive collector element (23) in a polymeric laminate lithium ion rechargeable battery is cleaned of surface oxides and coated with an adherent conductive polymer film (34) which is substantially inert to battery electrolyte components and prevents recurrent formation of insulative collector surface oxides, thereby maintaining effective electrode/collector electrical conductivity and significantly reducing internal battery resistance.

Material and method for low internal resistance LI-ion battery

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, the plasticizer of the polymeric composition is removed by leaching with a selective solvent and is replaced with a lithium salt electrolyte solution by simple imbibition. The battery thus activated may then be charged and recharged in the usual manner.

Electrolyte activatable 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.

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Far Hills, NJ, United States of America

Paul C Warren