Abstract: An alkaline cell having an anode comprising zinc and a cathode comprising manganese dioxide wherein the cathode is located annularly along the inside surface of the cell housing and has a plurality of indentations on the inside of its surface facing the cell interior. Each indentation has a wall defining a channel with an opening thereto running preferably in the direction of the cell's length. The channel and opening facing the cell interior filled with anode material. The cell can have an anode current collector, typically of metal, with at least a portion of its surface extending into the cathode indentation channel. The anode current collector can have a portion of its surface extending from a point within the anode and into the cathode indentation channel through said opening. The cell can include a cathode current collector comprising a sheet of conductive material such as a sheet of metal or graphite placed within the cathode, particularly within thick regions of the cathode.

Abstract: An alkaline cell having an anode comprising zinc and a cathode comprising manganese dioxide wherein the cathode is located annularly along the inside surface of the cell housing and has a plurality of indentations on the inside of its surface facing the cell interior. Each indentation has a wall defining a channel with an opening thereto running preferably in the direction of the cell's length. The channel and opening facing the cell interior filled with anode material. The cell can have an anode current collector, typically of metal, with at least a portion of its surface extending into the cathode indentation channel. The anode current collector can have a portion of its surface extending from a point within the anode and into the cathode indentation channel through said opening. The cell can include a cathode current collector comprising a sheet of conductive material such as a sheet of metal or graphite placed within the cathode, particularly within thick regions of the cathode.

Abstract: A process for heat treating an anode casing of a zinc/air depolarized cell after the casing has been formed but before anode material comprising zinc is inserted therein. The anode casing has a layer of copper on its inside surface. The process comprises heat treating the anode casing by passing a gas at a temperature between about 200° C. and 700° C., preferably between about 300° C. and 600° C. in contact therewith to form a heat treated anode casing and then cooling said heat treated anode casing to ambient temperature. The heat treated anode casing is stored away from atmospheric air until anode active material is inserted therein during cell assembly. The heat treating process significantly reduces gassing during cell discharge and storage and eliminates the need to add mercury to the anode material.

Abstract: A primary lithium cell having a wound electrode assembly. The electrode assembly comprises an anode comprising lithium, a cathode comprising a manganese dioxide and an electrolyte permeable separator therebetween. The electrode assembly comprises a cathode sheet, an anode sheet and electrolyte permeable separator sheet therebetween. The sheets are wound into a spiral roll. An exposed edge of each revolution of the separator sheet is then heat treated, for example, by applying a heated platen thereto to mold said exposed edge into a continuous separator membrane. The continuous separator membrane, so formed, covers and seals off said edge of adjacent revolutions of the cathode sheet and thus provides electrical insulation therefor. The electrode assembly can then be inserted into the cell casing so that the continuous separator membrane abuts a surface of the casing and provides electrical insulation between the casing and the wound cathode sheet.

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.

Abstract: The invention relates to an improved method for preparing a lithiated manganese dioxide having a stabilized &ggr;-MnO2-type crystal structure whereby an essentially dry mixture of manganese dioxide and a lithium salt is subjected to a mechanical activation process in the presence of milling media. The mechanical activation process serves to promote partial ion-exchange of protons present in the manganese dioxide crystal lattice and on the surface of the manganese dioxide particles by lithium cations. The formed lithium ion-exchanged intermediate product is heat-treated to form a lithiated manganese dioxide product having a &ggr;-MnO2-type crystal structure that can be advantageously included in the cathode of a lithium primary electrochemical cell.

Abstract: A novel battery assembly which includes an electrochemical cell positioned within an extruded, tubular housing; and, a method for making such a battery assembly.

Abstract: A removable tab for metal/air cell, particularly miniature zinc/air button cells which have a principal use as hearing aid batteries. The tab covers air holes in the surface of the cell. The tab has a stiff elongated member that has an extended portion which forms a handle for removing the tab from the cell in order to activate the cell. The tab also comprises a resilient material, preferably a polymeric foam. A portion of the resilient material is adhered to at least a portion of one side of the stiff elongated member and another portion of the resilient material is adhered to cover air holes in the cell surface. A polymeric film can be inserted between the foam and cell surface. The resilient material conforms better to the cell surface which can typically have curved, grooved or depressed regions in addition to the air holes. The resilient material provides more uniform adhesion of the tab to the cell surface with releasable pressure sensitive adhesives.

Abstract: An anode composition for zinc/air cells comprises a metal binder added to particulate zinc. The metal binder in contact with the particulate zinc is heated to above its melting point. Upon cooling the metal binder solidifies and adheres to the zinc particle surfaces to form agglomerates wherein individual zinc particles are held bound to each other by the metal binder. Gelling agent and electrolyte can then be added to form an anode mixture. The metal binder has a melting point desirably above about 35° C. and below the melting point of zinc. A preferred metal binder for the particulate zinc is an alloy of indium and bismuth (In/Bi). Other desirable metal binders, for example, can be an alloy of indium, bismuth and tin (In/Bi/Sn) or alloy of indium and tin (In/Sn) as well as indium metal. Use of the metal binder in the anode mixture improves conductivity of the zinc particles and replaces the need to add mercury to the anode composition.

Abstract: The performance of alkaline cells comprising a zinc anode and manganese dioxide cathode can be improved, especially in high power application, by applying thermal insulating material to the cell casing. The thermal insulation material can be conveniently applied between the cell label and casing. The thermal insulating material significantly reduces the overall heat transfer coefficient, Uo, for the cell. The insulation increases the internal temperature of the cell during discharge, resulting in better performance.

Abstract: The performance of alkaline cells comprising a zinc anode and manganese dioxide cathode can be improved, especially in high power application, by the addition of electrically conductive powders such as tin, copper, silver, magnesium, indium or bismuth to the anode mixture. The conductive powders are in physical mixture with the zinc particles. A preferred electrically conductive powder is tin powder. The alkaline cell to which the conductive powders are added preferably contain no added mercury and preferably are also essentially free of lead.

Abstract: An alkaline cell is disclosed having a cathode comprising manganese dioxide wherein the cathode is a semisolid during discharge of the cell. The cell has an anode comprising zinc and an electrolyte comprising potassium hydroxide. The semisolid cathode comprising manganese dioxide may be in the form of a putty or paste. The semisolid cathode reduces cathode polarization effects and results in increased manganese dioxide utilization (Amp-hr/g), particularly at high current drain, between about 0.5 and 2 Amp. The porosity of the cathode is between about 45% and 70%, and the volume ratio of electrolyte solution in the cathode to the solids in the cathode is at a value between about 0.7 and 2.3.

Abstract: A lithiated manganese dioxide for use in primary lithium electrochemical cells. The lithiated manganese dioxide is prepared by stepwise treatment with a liquid source of lithium cations that can include an aqueous solution of a lithium base or a low melting point lithium salt resulting in formation of a lithiated manganese dioxide product. Lithium cations in the lithium base or molten lithium salt can be ion-exchanged with hydrogen ions in the manganese dioxide crystal lattice and additional lithium ions reductively inserted into the lattice during subsequent heat-treatment to form the lithiated manganese dioxide product LiyMnO2−&dgr;. The primary lithium cell utilizing the lithiated manganese dioxide product as active cathode material exhibits increased operating voltage and enhanced high rate, low temperature, and pulse discharge performance compared with untreated manganese dioxide.

Abstract: A process is described whereby commercial manganese dioxide, for example, electrolytic manganese dioxide (EMD), is treated with ozone before it is utilized as cathode active material in an alkaline cell. The pretreatment of the manganese dioxide is accomplished by contacting manganese dioxide with ozone gas. Alternatively, the manganese dioxide may be treated with ozone while the cathode comprising said manganese dioxide is already in the cell casing. The treatment of the manganese dioxide improves the cell's open circuit voltage (OCV) and results in an increase in service life of the cell, particularly under high power application.

Abstract: A method of making lithium manganese oxide of spinel structure is disclosed. The method involves the step of prelithiating a manganese oxide by reacting it with lithium hydroxide or lithium salt and then reacting the prelithiated manganese oxide in a second step at elevated temperature, for example, with lithium carbonate to form a lithium manganese oxide spinel. The spinel product may be used advantageously in secondary (rechargeable) batteries. The spinel product may be admixed with a partially substituted nickelite, preferably, LiNi.sub.x Co.sub.1-x O.sub.2 (0.1<x<0.9) or LiNi.sub.x Mg.sub.1-x O.sub.2 (0.85<x<0.97) and mixtures thereof to form the active material for the positive electrode of a rechargeable lithium ion cell. A preferred mixture for the positive electrode of lithium ion cells comprises lithium manganese oxide spinel and LiNi.sub.x Co.sub.1-x O.sub.2 (0.1<x<0.9).