Rayovac Corporation

Rovcal, Inc.

Gregory Scott Moy

Robert B Dopp

John Edward Oltman

Joseph Lynn Passaniti

Michael Andrew Ward

Ernest Ndzebet

William C Bushong

Viet H Vu

Jeffrey A Poirier

Miguel E Armacanqui

Robert B Loch

David R Mihara

Susan Jean Launder

Edgar M Armacanqui

A sulfonic acid type organic surfactant is incorporated into the gelled anode mixture of an alkaline electrochemical cell, optionally with an organic phosphate ester surfactant. Zinc fines may also be incorporated into the anode. The electrolyte included in the anode mixture may have a reduced hydroxide concentration. When a cell is provided whose anode mixture includes the two surfactants and zinc fines alone or in combination with a lowered hydroxide concentration in the electrolyte, discharge leakage is reduced and gel gassing is suppressed relative to that of gels lacking both surfactants. Additionally, cell discharge performance is improved relative to that of cells lacking both the zinc fines and lowered hydroxide concentration.

Alkaline cell with performance enhancing additives

An elongate, generally tubular, air depolarized electrochemical cell ( ) comprising a cathode ( ), including an air cathode assembly ( ), extending about the tubular circumference, and along the tubular length, of the cell ( ), an anode ( ), a separator ( ) between the anode ( ) and the cathode ( ), electrolyte, a top closure member ( ), and a bottom closure member ( ). The cathode assembly ( ) is fixedly held, by a friction fit, in a slot ( ) at the bottom of the cell. The slot can be developed, for example, by inner ( ) and outer ( ) walls of a cathode can ( ), by inner ( ) and outer ( ) walls of a bottom closure member ( ), or by an outer wall ( ) of a cathode can ( ) and an opposing outer wall of a plug ( ) on the interior of the cell. Preferably, bottom closure structure of the cell ( ) and receives a bottom edge portion ( ) of the cathode current collector ( ), and makes electrical contact with the bottom edge portion ( ), preferably at an inner surface ( ) of the cathode current collector. A diffusion member ( ) of the cathode assembly ( ) is preferably compressed as a seal, at the bottom of the cell ( ), between an outer side wall ( ) of the cell and the remainder of the cathode assembly ( ). The diffusion member ( ) is also used at least as an assist in sealing the cell ( ) against electrolyte leakage from the anode cavity ( ) and past the cathode assembly ( ). An embodiment may provide a stop ledge ( ) in grommet ( ) facing a stop groove ( ) in a cathode can ( ). The cathode assembly ( ) can extend into a slot ( ) at an outer edge of the grommet ( ). A top grommet ( ) can have an upwardly extending leg ( A) overlain by a top closure member ( ). The air diffusion member ( ) may control the rate of entry of air to the reaction surface, depending on density of the air diffusion member ( ), whereby the air diffusion member ( ) controls the limiting current of the cell ( ). The air cell ( ) can be free from adhesive bonding the separator ( ) to the cathode assembly ( ). The bottom of the cathode current collector ( ) may be in a bottom slot ( ), in a path of flow of current between a reaction surface and a positive electrode terminal ( ). A method of fabricating cells can including crimping a top washer ( ) and an outer leg ( ) of a top grommet ( ) at the same time, including closing a slot ).

Air depolarized electrochemical cells

An elongate, generally tubular, air depolarized electrochemical cell ( ) comprising a cathode ( ), including an air cathode assembly ( ), extending about the tubular circumference, and along the tubular length, of the cell ( ), an anode ( ), a separator ( ) between the anode ( ) and the cathode ( ), electrolyte, a top closure member ( ), and a bottom closure member ( ). The cathode assembly ( ) is fixedly held, by a friction fit, in a slot ( ) at the bottom of the cell. The slot can be developed, for example, by inner ( ) and outer ( ) wars of a cathode can ( ), by inner ( ) and outer ( ) walls of a bottom closure member ( ), or by an outer wall ( ) of a cathode can ( ) and an opposing outer wall of a plug ( ) on the interior of the cell. Preferably, bottom closure structure of the cell ( ) and receives a bottom edge portion ( ) of the cathode current collector ( ), and makes electrical contact with, the bottom edge portion ( ), preferably at an inner surface ( ) of the cathode current collector. A diffusion member ( ) of the cathode assembly ( ) is preferably compressed as a seal, at the bottom of the cell ( ), between an outer side wall ( ) of the cell and the remainder of the cathode assembly ( ). The diffusion member ( ) is also used at least as an assist in sealing the cell ( ) against electrolyte leakage from the anode cavity ( ) and past the cathode assembly ( ). Various embodiments comprehend a variety of bottom seal members ( ) between the bottom wall ( ) and the electroactive anode material ( ), typically in combination with a bottom slot ( ) receiving the cathode assembly ( ) adjacent an outer side wall ( ) of the bottom closure member ( ).

Bottom seals in air depolarized electrochemical cells

An air depolarized cell comprises an anode, a cathode, including an air cathode assembly openly exposed to the ambient environment and/or defining at least a portion of the outer surface of the cell. The cell can comprise a bottom member defining a bottom of the cell, and a top member defining a top of the cell, the air cathode assembly extending between the bottom member and the top member as the exposed or outer portion of the cell. An anode cavity can be disposed inwardly of the separator and upwardly of the bottom member, and contain a mass of electroactive anode material. An elongate anode current collector preferably extends into the anode material. The top member can comprise a top contour washer having inner and outer downwardly depending legs receiving an upper edge portion of the cathode assembly in a slot therebetween, and an insulating grommet in the slot, electrically insulating the cathode assembly from the top contour washer and sealing against liquid leakage out of the cell through the slot.

Air depolarized electrochemical cell

Cathode assembly precursor cathode assembly (,) and elongate air depolarized electrochemical cells (,) made therewith. Cathode assembly precursor comprises a closed-loop elongate cathode current collector (,), and perforations (,) from outer to inner surfaces, and catalystically active carbon extending into the perforations (,). The current collector (,) can be cylindrical and can be free from longitudinal jointing, or can have a longitudinal joint (,), preferably free from overlap of the side wall. The current collector (,) can comprise an imperforate edge region at the top (,) and/or bottom (,), left (,) and/or right (,) edge. The perforations (,) define an open traction of the wall, of about 45 to about 70 percent. Typical cathode assemblies (,) have air diffusion member (,) on the outer surface of the cathode assembly (,). Such air diffusion member (,) typically has thickness of about 0.0025 to 0.005 inch (about 0.06 to about 0.13 mm.), and comprises a reduced thickness endless wrap extending at least 1.5 times, preferably 2 times, or 3 times, about the current collector (,), discouraging transfer of moisture vapor into or out of a cell, discouraging leakage, and controlling air diffusion rate. The diffusion member (,) extends beyond the top edge (,) of the current collector, and is folded in and down about the top edge (,) and inner surface (,) of the cathode assembly (,). The cathode current collector (,) can be mounted on a mandrel (,), the carbon sheet (,) passing through a nip defined between (i) support structure (,) having greater arc radius than the mandrel (,) and (ii) the mandrel (,), and applying force at the nip to consolidate the carbon (,) onto the side wall (,), passing air diffusion material (,) through the nip, and applying force to consolidate the air diffusion material (,) onto the carbon (,). The invention contemplates fabricating an air cathode assembly (,) comprising mounting the current collector (,) on a mandrel (,), defining an arc having a radius smaller than the arc of the cathode current collector (,), mounting the combination mandrel (,) and cathode current collector (,) in a stack (,) of assembly rolls (,A,,B,,C,,D), making a sheet stack of carbon sheets (,B,,C,,D), passing the sheet stack through a nip, and applying force to the stack, reducing thickness of the stack, and passing air diffusion material (,) through the nips and applying force to consolidate the diffusion material (,) onto the carbon (,).

Composite carbon sheet, and electrochemical cells made therewith

This invention teaches an elongate air depolarized electrochemical cell. The cell has a cathode, including an air cathode assembly, and a separator disposed inwardly of the air cathode assembly. A bottom member defines a bottom of the cell. An anode cavity, defined inwardly of the separator and the bottom member, receives a mass of electroactive anode material. An elongate hollow tube anode current collector is in electroactive contact with the mass of electroactive anode material. The anode current collector preferably has an enlarged cross-section such that the average distance between the anode current collector and the separator is reduced, thereby to reduce the overall mass of electroactive anode material used in the cell.

Air depolarized electrochemical cell having mass-control chamber in anode

An elongate, generally tubular, air depolarized electrochemical cell (,) comprising a cathode (,), including an air cathode assembly (,), extending about the tubular circumference, and along the tubular length, of the cell (,), an anode (,), a separator (,) between the anode (,) and the cathode (,), electrolyte, a top closure member (,), and a bottom closure member (,). The cathode assembly (,) is fixedly held, by a friction fit, in a slot (,) at the bottom of the cell. The slot can be developed, for example, by inner (,) and outer (,) walls of a cathode can (,), by inner (,) and outer (,) walls of a bottom closure member (,), or by an outer wall (,) of a cathode can (,) and an opposing outer wall of a plug (,) on the interior of the cell. Preferably, bottom closure structure of the cell (,) and receives a bottom edge portion (,) of the cathode current collector (,), and makes electrical contact with the bottom edge portion (,), preferably at an inner surface (,) of the cathode current collector. A diffusion member (,) of the cathode assembly (,) is preferably compressed as a seal, at the bottom of the cell (,), between an outer side wall (,) of the cell and the remainder of the cathode assembly (,). The diffusion member (,) is also used at least as an assist in sealing the cell (,) against electrolyte leakage from the anode cavity (,) and past the cathode assembly (,). Various embodiments comprehend crimping bias in various members at the bottom of the cell (,), to develop the friction fit that fixedly holds the cathode assembly (,) at the bottom of the cell (,). In a can-less embodiment, top (,) and bottom (,) closure members can be separate and distinct from each other, and at least a portion of the air cathode assembly (,) is openly exposed as an outer surface to the ambient environment. A portion of the air diffusion member (,) is compressed in the bottom closure member as a seal.

Elongate air depolarized electrochemical cells

An elongate air depolarized electrochemical cell (,). A grommet (,) closes the top of the cell (,). A seal (,) can extend upwardly into a slot (,) between the grommet (,) and a top closure member (,) such as at the top of a cathode can (,), or a separate top closure member (,). Cathode assembly (,) and separator (,) can extend into the slot (,). The seal is between the grommet (,) and cathode assembly (,), or between grommet (,) and separator (,). or both. The seal can extend upwardly into the slot (,) from an outer surface of the cathode assembly (,), can extend about respective upper edges of the cathode current collector (,), catalyst, and separator (,), and downwardly toward, preferably against or along the inner surface of, the separator (,). The top closure member (,) can be crimped against the grommet (,) at the slot (,), with the cathode assembly (,), and optionally the separator (,), in the slot (,) between the grommet (,) and the top closure (,), thus to provide a liquid-tight crimp seal. The top closure (,) can be crimped first against the grommet (,) at the slot (,), and further crimped against the grommet (,) at a second locus (,) displaced longitudinally from the first crimp. Composition of the seal comprises a microporous polymer (,), preferably polytetrafluoroethylene. Preferred embodiments comprise at least two, preferably at least three, layers of air permeable microporous sheet material, useful for diffusion of air therethrough to the cathode reaction surface (,). The layers are wrapped continuously and without intervening end, to form an outer surface of the cathode assembly (,). Another expression of the invention is a cathode assembly (,), or cathode-separator combination, for use in an elongate air depolarized cell (,). The air permeable sheet material (,), as wrapped about the tubular cathode assembly, is compressed so as to have a compressed thickness less than the uncompressed thickness. The invention still further comprehends an elongate air depolarized cell (,) comprising an anode, a cathode, or cathode-separator combination as described herein, and electrolyte.

Seals, and electrochemical cells made therewith

An elongate, generally tubular, air depolarized electrochemical cell (,) comprising a cathode (,), including an air cathode assembly (,), extending about the tubular circumference, and along the tubular length, of the cell (,), an anode (,). a separator (,) between the anode (,) and the cathode (,), electrolyte, a top closure member (,), and a bottom closure member (,). The cathode assembly (,) is fixedly held, by a friction fit, in a slot (,) at the bottom of the cell. The slot can be developed, for example, by inner (,) and outer (,) walls of a cathode can (,), by inner (,) and outer (,) walls of a bottom closure member (,), or by an outer wall (,) of a cathode can (,) and an opposing outer wall of a plug (,) on the interior of the cell. Preferably, bottom closure structure of the cell (,) and receives a bottom edge portion (,) of the cathode current collector (,), and makes electrical contact with the bottom edge portion (,), preferably at an inner surface (,) of the cathode current collector. A diffusion member (,) of the cathode assembly (,) is preferably compressed as a seal, at the bottom of the cell (,), between an outer side wall (,) of the cell and the remainder of the cathode assembly (,). The diffusion member (,) is also used at least as an assist in sealing the cell (,) against electrolyte leakage from the anode cavity (,) and past the cathode assembly (,). The tubular cathode current collector (,) has novel border regions (,), novel longitudinal joint structure (,), novel perforations (,), and including novel methods of making such cathode current collectors (,) and such cells (,).

Tubular air depolarized cell

An elongate, generally tubular, air depolarized electrochemical cell (,) comprising a cathode (,), including an air cathode assembly (,), extending about the tubular circumference, and along the tubular length, of the cell (,), an anode (,), a separator (,) between the anode (,) and the cathode (,), electrolyte, a top closure member (,), and a bottom closure member (,). The cathode assembly (,) is fixedly held, by a friction fit, in a slot (,) at the bottom of the cell. The slot can be developed, for example, by inner (,) and outer (,) walls of a cathode can (,), by inner (,) and outer (,) walls of a bottom closure member (,), or by an outer wall (,) of a cathode can (,) and an opposing outer wall of a plug (,) on the interior of the cell. Preferably, bottom closure structure of the cell (,) and receives a bottom edge portion (,) of the cathode current collector (,), and makes electrical contact with the bottom edge portion (,), preferably at an inner surface (,) of the cathode current collector. A diffusion member (,) of the cathode assembly (,) is preferably compressed as a seal, at the bottom of the cell (,), between an outer side wall (,) of the cell and the remainder of the cathode assembly (,). The diffusion member (,) is also used at least as an assist in sealing the cell (,) against electrolyte leakage from the anode cavity (,) and past the cathode assembly (,). Various embodiments comprehend crimping the outer side wall against the cathode assembly and thereby developing a crimping bias in the outer side wall which holds the cathode assembly in the slot, by friction, between the outer and inner side walls.

Growing community of inventors

Madison, WI, United States of America

Gregory Scott Moy