Abstract:
An apparatus and method for treating a cathode material provided on a surface of a continuous thin-film substrate and a treated thin-film cathode having increased smoothness are disclosed. A web of untreated cathode material is moved between a feed mechanism and a take-up mechanism, and passed through a treatment station. The web of cathode material typically includes areas having surface defects, such as prominences extending from the surface of the cathode material. The surface of the cathode material is treated with an abrasive material to reduce the height of the prominences so as to increase an 85 degree gloss value of the cathode material surface by at least approximately 10. The web of cathode material may be subjected to a subsequent abrasive treatment at the same or other treatment station. Burnishing or lapping film is employed at a treatment station to process the cathode material. An abrasive roller may alternatively be used to process the web of cathode material. The apparatus and method of the present invention may also be employed to treat the surface of a lithium anode foil so as to cleanse and reduce the roughness of the anode foil surface.
Abstract:
This present invention provides a method for creating a gas restrictive interface between a battery case partition formed in a battery case and a battery plate strap, which extends through the partition in a series connection and is part of a battery cell block, which is received within the battery case. The battery case partition includes a notch having a sealing material disposed thereon so that when a heated battery plate strap is positioned within and across the notch, a first gas restrictive interface results between the battery plate strap and the case partition. A battery case lid having a partition tab extending therefrom forms a second gas restrictive interface with top surface if the battery plate strap by being received and secured within the notch of the battery case partition. The bottom edge of the partition tab includes the sealing material to complete the gas restrictive interface.
Abstract:
The difficulties encountered with attaching tabs to very thin metal layer. e. g., a layer of gold from 0.3 &mgr;m to 50 &mgr;m thick are severe. Typically, in the uses envisioned for the thin metal layer, which is for a compact battery, a plastic sheet such as polyimide underlies the thin metal layer. Polyimide has a relatively low melting point. The thin polyimide substrate melts when resistance welding is used. Ultrasonic welding doesn't work because the sound wave energy is absorbed by the polyimide. This invention solves the attachment problem by using wire bonding to the thin metal sheet and to its tab. The tab attachment for a thin metal layer comprises a thin metal layer, a metal tab, and a wire and the wire is bonded to the thin metal layer and the wire is bonded to the metal tab. The thin metal layer may be gold; the thickness of the gold is between 0.3 &mgr;m and 50.0 &mgr;m.
Abstract:
A zinc/air button cell having an adhesive sealant applied to a portion of the inside surface of the cell's cathode casing. The adhesive sealant can be applied to the inside surface of a recessed annular step surrounding the cell's positive terminal on the cathode casing. The adhesive is preferably applied in a pattern which conforms to the shape of the annular recessed step. An electrolyte barrier sheet, preferably of Teflon, can be applied to the adhesive pattern on the inside surface of said recessed step, preferably so that the adhesive bonds the edge of the barrier sheet to the step. The adhesive prevents electrolyte from leaking from the cell. The adhesive is applied preferably by preparing a plate having a desired pattern etched thereon, filling the etching in the plate with an adhesive mixture, applying a silicon pad to the etching to transfer the adhesive pattern to the pad, then applying the pad to the inside surface of the cathode casing step to transfer the adhesive pattern thereto. The adhesive is preferably a solvent based mixture comprising a polyamide.
Abstract:
A method of producing a battery cell anode is described wherein the manufacturing process of the anode commences with a sputtering target with a composition of Li3Sn. The target is sputtered in an argon-nitrogen (Ar—N2) gas mixture, wherein the nitrogen gas is limited to within a range of 0.5%-15% of the total volume of gas. The sputtering of the target produces a Sn:Li3N anode layer.
Abstract:
A process for producing an electrode for a battery, wherein electrode active material layers are firmly formed on both surfaces of a current collector for the electrode. An electrode coating containing an electrode active material, a binder, a solvent and an acid is applied to one surface of an electrode current collector, then dried, and the other surface of the current collector is cleaned with water, and the electrode active material layer is formed on the other surface of the current collector.
Abstract:
A method for forming lithium electrodes having protective layers involves plating lithium between a lithium ion conductive protective layer and a current collector of an “electrode precursor.” The electrode precursor is formed by depositing the protective layer on a very smooth surface of a current collector. The protective layer is a glass such as lithium phosphorus oxynitride and the current collector is a conductive sheet such as a copper sheet. During plating, lithium ions move through the protective layer and a lithium metal layer plates onto the surface of the current collector. The resulting structure is a protected lithium electrode. To facilitate uniform lithium plating, the electrode precursor may include a “wetting layer” which coats the current collector.
Abstract:
A method for manufacturing a lithium polymer secondary battery includes the steps of fabricating a unit cathode plate, a unit anode plate and a separator each having a plasticizer, extracting each plasticizer from the unit cathode plate, the unit anode plate and the separator and drying the same, stacking the cathode plate and the unit anode plate and interposing the separator therebetween to form a unit battery cell, and impregnating the unit battery cell with an electrolytic solution. Therefore, the battery productivity can be improved. Also, expanded metal or punched metal as well as a foil can be used as cathode and anode current collectors of the lithium polymer secondary battery.
Abstract:
An electrochemical cell constructed in accordance with the present invention includes a can for containing electrochemical materials including positive and negative electrodes and an electrolyte, the can having an open end and a closed end; an integral seal/inner cover assembly positioned in the open end of the can, the integral seal/inner cover assembly having a rigid inner cover and a seal preformed directly onto at least an inner-facing surface of the rigid inner cover; a collector extending through a central hole provided in the integral seal/inner cover assembly and into the can so as to contact one of the electrodes; and an outer cover positioned across the open end of the can proximate an outer-facing surface of the rigid inner cover, the outer cover being positioned so as to be in electrical contact with the collector. The rigid inner cover preferably includes at least one aperture extending from the inner-facing surface to the outer-facing surface of the inner cover. The aperture being filled by the seal to provide a pressure relief that relieves internal pressure from the can when the internal pressure becomes excessive. Preferably, the seal is made of rubber and is molded directly onto the rigid inner cover.
Abstract:
A method of forming a seal between a lead on a battery cell and flexible packaging enclosing the cell that comprises the steps of chemically cleaning at least a portion of a lead of a battery; roughening the surface of the portion of a lead to increase the surface area thereof; coating the entire periphery of the portion of a lead with a layer of a first polymeric material; the coating having a minimum thickness about equal to the thickness of the lead; positioning the portion of the lead between two flexible laminate sheets, the laminate sheets each having a layer of a second polymeric material, the laminate sheets being positioned to engage each other wherein the portion of the lead is disposed between the polymeric layers of the flexible laminate sheet; and applying sufficient heat and pressure to the flexible laminate sheets to soften the polymeric layers on the flexible laminate to cause the polymer layers to flow around and completely coat the layer of polymeric material on the lead.