Abstract: A battery plate wrapper blank comprising a sheet of plate wrapper material is provided with attached longitudinal edge protective strips positioned to overlay the longitudinal sides of a battery plate which it is adapted to envelope and with a bottom edge protective strip attached along the bottom transverse margin of the sheet to overlay the bottom edge of the battery plate. The unitary plate wrapper blank is formed into a plate pouch without need of additional elements. Varients of the plate wrapper blank provide inner, outer or inner and outer longitudinal edge protective strips for the pouch, and a seal strip for the longitudinal seam of the pouch.

Abstract: A primary cell separator basket is formed from sheet material folded upon itself to form a basket bottom at the fold and bonded along margins in face to face contact extending from the fold. One or both sheet faces between the bonded margins are crowned outwardly to preform the basket and open its top. Basket preforms can be made in strips by longitudinally folding strip sheet material, crowning the material at intervals along the strip length and bonding the material in face to face relationship transverse of the strip length along the strip length in regions which fall between the crowns.

Abstract: A separator plate for the negative electrode of a lead-acid battery comprising a molded, synthetic plastic wall or planar member of generally rectangular configuration. A pair of like separator plates are vertically oriented in the battery casing to sandwich the negative electrode therebetween including juxtaposed retention mats common in such a negative electrode assembly. The sandwich provides a clear-through channel along opposite extremities of the electrode for flow of electrolyte. The sandwich assembly is maintained by means of cooperating locking and sealing formations integral with the separator plates of the assembly. Wrapping of the positive electrode thereby is rendered unnecessary when assembling the battery and enables automated assembly of the battery using the separator plate sandwich.

Abstract: A lead-acid battery cell wherein each cell includes a compressed assembly of negative plates (2,3), separators (5) and positive plates (1).The positive plates (1) are sandwiched between two microporous separator elements (4) having dimensions greater than that of the plates and the plate edges are coated with an epoxy resin ribbon (20), which is provided by pouring resin into the channel between the projecting portions of the separators.

Abstract: A method for manufacturing tubular shaped thermoplastic members comprising conveying two thin sheets of thermoplastic material in close substantially parallel relationship through an ultrasonic welding station for forming a plurality of continuous spaced apart seams substantially parallel to the direction of conveying for joining the two sheets of thermoplastic material. The seams, thus formed, are cut substantially parallel to the direction of conveying such that the two sheets of thermoplastic material remain joined adjacent each side of the cuts. Preferably, the cutting takes place substantially simultaneously with the ultrasonic formation of the seams and the thin sheets of thermoplastic material are cooled prior to the ultrasonic welding. An apparatus for practicing the method is also disclosed. The method and apparatus are particularly adaptable for the manufacture of ionically permeable thermoplastic separators for use in electrochemical cells and the like.

Abstract: An electric storage battery including plates of one polarity sheathed in envelopes of separator material wherein each envelope includes a pouch for supporting the distal end of an adjacent opposite polarity plate.

Abstract: A battery separator material which is folded to form an envelope is heat sealed along at least two opposing edges thereof to form a battery separator. The separator material is comprised of discrete polyolefin pulp fibers in a sufficient amount to heat seal the separator along its edges. The fibers are bound by an organic polymeric binder. A process of forming the battery separator is also disclosed.

Abstract: An electric storage battery having an electrochemically active cell element comprising juxtaposed positive and negative polarity electrode plates each at least partially encased in a sheath of microporous dendrite-suppressing battery separator material. Each of the sheaths is sealed along three of its peripheral borders and open on the fourth. The several plates are arranged in the cell element such that the opening in the sheaths for the positive plates face a direction opposite to the direction faced by the openings in the sheaths for the negative plates and such that the sheaths on adjacent plates overlap in the region between adjacent plates.

Abstract: A method is provided for sealing portions of cation exchange membranes of carboxylic acid type fluorinated polymers. The portions of the membranes to be sealed are in the ester form of the membrane and are ultrasonically sealed at sealing times of from about 0.1 to about 5 seconds while employing power in the range of from about 50 to about 600 watts.The novel method of the present invention can be used to repair membranes of carboxylic acid type fluorinated polymers which have been torn, slit, or cut. Sections of membrane materials may be sealed together to form an enlarged or reinforced membrane. The sealed portions are substantially free of wrinkles and are not mechanically damaged or weakened.

Abstract: A separator for an electrolytic cell or similar cell is made of a porous polymeric material, preferably porous polytetrafluoroethylene, and comprises a plurality of tubular portions of such material with one or two flange(s) at end(s) thereof for sealing to other such flanges and to the cell. The flanges are so constructed that when being sealed in place they do not strain or tear and do not strain or tear the material of the tubular portions. The separator is especially useful as a replacement for deposited asbestos diaphragms in electrolytic cells for the manufacture of chlorine and caustic.

Abstract: A film-forming polyvinyl alcohol polymer is mixed with a polyaldehyde-polysaccharide cross-linking agent having at least two monosaccharide units and a plurality of aldehyde groups per molecule, preferably an average of at least one aldehyde group per monosaccharide units. The cross-linking agent, such as a polydialdehyde starch, is used in an amount of about 2.5 to 20% of the theoretical amount required to cross-link all of the available hydroxyl groups of the polyvinyl alcohol polymer. Reaction between the polymer and cross-linking agent is effected in aqueous acidic solution to produce the cross-linked polymer. The polymer product has low electrical resistivity and other properties rendering it suitable for making separators for alkaline batteries. In that event, the mixture of polymer and cross-linking agent is formed into a sheet or film or the like and the film is cut to size and otherwise fabricated into a configuration suitable for a particular end use.

Abstract: A method of producing a cross-linked polyvinyl alcohol structure, such as a battery separator membrane or electrode envelope. An aqueous solution of a film-forming polyvinyl alcohol is admixed with an aldehyde cross-linking agent at basic pH to inhibit cross-linking. The cross-linking agent, preferably a dialdehyde such as glutaraldehyde, is used in an amount of from about 1/2 to about 20% of the theoretical amount required to cross-link all of the hydroxyl groups of the polymer. The aqueous admixture is formed into a desired physical shape, such as by casting a sheet of the solution. The sheet is then dried to form a self-supporting film. Cross-linking is then effected by immersing the film in aqueous acid solution. The resultant product has excellent properties for use as a battery separator, including a low electrical resistivity, the value of which is principally determined by the amount of cross-linking which is easily and closely controlled by the amount of cross-linking agent added to the polymer.

Abstract: Sections of synthetic materials, such as thermoplastic materials, suitable for use in electrolytic cells for the production of chlorine and sodium hydroxide, are joined together in a reinforced liquid-tight seam by a method which comprises positioning sections of material to be joined adjacent to but spaced apart from each other, to form a gap between the sections, placing a thermoplastic sealing composition in the gap, sewing the sections of synthetic material and the thermoplastic sealing composition together to form a seam, heating the seam to a temperature sufficient to melt the thermoplastic sealing composition without melting the synthetic material or the thread thereby allowing the melted thermoplastic sealing composition to flow to and fill perforations in the synthetic material adjacent to the thread. The seam is then cooled to solidify the thermoplastic sealing composition and to form a reinforced liquid-tight seam between the sections of synthetic material.

Abstract: A self-supporting sheet structure comprising a water soluble, non-cross-linked polymer such as polyvinyl alcohol which is capable of being cross-linked by reaction with hydrogen atom radicals and hydroxyl molecule radicals is contacted with an aqueous solution having a pH of less than 8 and containing a dissolved salt in an amount sufficient to prevent substantial dissolution of the non-cross-linked polymer in the aqueous solution. The aqueous solution is then irradiated with ionizing radiation to form hydrogen atom radicals and hydroxyl molecule radicals and the irradiation is continued for a time sufficient to effect cross-linking of the water soluble polymer to produce a water-insoluble polymer sheet structure. The method has particular application in the production of battery separators and electrode envelopes for alkaline batteries.

Abstract: Separator materials suitable for use in electrolytic cells, for example, for the electrolysis of alkali metal chloride brines, are sealed by a method which comprises coating the sections to be sealed with a synthetic thermoplastic sealing agent and ultrasonically sealing the coated portions.The method permits the sealing-in-place of separator materials and allows them to be unsealed and resealed without damage to the separators.

Abstract: A battery plate separator is characterized by polypropylene filter media material which is readily formed into pouches for receiving and encapsulating battery plates. The separator enables a free flow of electrolyte ions between adjacent plates while simultaneously preventing electrode dendrite penetration therebetween, is highly resistant to deterioration in the presence of electrolytes normally encountered in batteries, significantly extends the life of batteries constructed therewith, and provides a very thin yet highly efficient wrapping around the plates so that a greater number of plates may be packaged into a battery of given size for increased battery capacity.

Abstract: A sheet of sintered PVC battery separator material is folded around a battery plate along the bottom edge thereof and heat sealed to itself along the lateral edges of the plate to form an envelope around the plate. The fold is then contacted with a plasticizer (i.e., n-methyl-2-pyrolidone) to toughen it against damage such as splitting, cracking, chipping, etc. during subsequent in-plant handling of the plates. Dimethyl and/or diethyl phthalate may be added to the n-methyl-2-pyrolidone to provide toughening for periods up to about five days.

Abstract: A battery separator in which plural sheets of microporous plastic material are connected by a strip or strips of polyvinylchloride in a manner suitable to form a sleeve. The strips may be high frequency heat sealed to the sheets or may be bonded thereto by solvating the outer edge portions of the strips, applying pressure between the strips and the sheets, and allowing the solvent to evaporate. A method of manufacturing a battery separator of the above type.

Abstract: An apparatus for the fabrication of battery separator sleeves in which two sheets of microporous plastic material are bonded to intermediately-disposed sealing strips by solvent welding or solvent adhesive bonding. Dispensers continuously apply solvent or solvent adhesive to the interfaces between continuous lengths of parallel, superposed sheet material and two, continuous lengths of sealing strips disposed between and along the lateral edges of the sheet materials. Bonding is achieved by subjecting the assembled materials to pressure applied by a series of pressure rollers and to heat applied to the lateral edges of the sheet materials by heating elements. The continuous length of formed battery separator sleeve is cut to the appropriate length.

Abstract: A battery separator envelope is provided having two walls of battery separator connected together by a foam member. In a method, two walls of battery separator are secured on a mandrel by sandwiching the mandrel and the walls of battery separator in a jig. A foam bead is then extruded between the walls and the bead is tamped and squeezed to complete the final formation of the foam member. The apparatus includes the mandrel, jig, extruder and support for guiding the jig assembly past the extruder.

Abstract: A high rate rechargeable silver-zinc pile type battery including a plurality of bipolar electrodes which are assembled into a full scale multi-cell pile. Each of bipolar electrodes includes a positive side having a porous silver matrix attached to silver foil and a negative side having a porous zinc structure vapor deposited on silver foil. A separator including three different components in layers is disposed between the positive and negative sides of the bipolar electrode. An epoxy adhesive is used to position and retain a seal in its proper location to electrically isolate the individual electrodes and form a cavity for retention of the electrolyte. Intercell connectors of etched silver foil serve as the cell case and active material substrate as well as the series connection between individual cells for electrical continuity.

Abstract: A secondary electrochemical cell includes electrodes separated by a layer of electrically insulative powder. The powder includes refractory materials selected from the oxides and nitrides of metals and metaloids. The powdered refractory material, blended with electrolyte particles, is compacted as layers onto an electrode to form an integral electrode structure and assembled into the cell. The assembled cell is heated to its operating temperature leaving porous layers of electrically insulative, refractory particles, containing molten electrolyte between the electrodes.

Abstract: A battery preferably for use as a power source in an electrical vehicle includes a plurality of envelope separators for reducing the concentration of waste products at the surface of the battery plates. The envelope separators comprise two thin sheets of microporous material which are bonded together at their edges and placed between each of the plates of the battery. The envelope separators while being nonconductive are highly porous thereby allowing electrical current to pass from one plate to the other through the separators in the electrolytic solution of the battery. The electrolyte is pumped into each envelope separator under pressure and is forced out through the pores or small holes in the sides of the envelope to flush water, gas and loose particles of active material away from the plates of the battery.

Abstract: A maintenance free storage battery has a plurality of alternately positive and negative plates disposed within an electrolyte in a battery container, with the plates resting on the bottom of the container. A battery separator material is disposed between each pair of adjacent plates with the bottom of the separator material forming openings to permit access of a bonding material to the lower edges of the plates. A bonding material adhered to both the bottom wall of the battery container and the lower edges of the plates extends through the bottom openings formed by the separator material to provide vibration resistance, with the bonding material also sealing the bottom openings to prevent the treeing of active material between positive and negative plates at the bottom of the container.