Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/64—Carriers or collectors
  • H01M4/70—Carriers or collectors characterised by shape or form
  • H01M4/80—Porous plates, e.g. sintered carriers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/64—Carriers or collectors
  • H01M4/66—Selection of materials
  • H01M4/663—Selection of materials containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
  • B22F3/10—Sintering only
  • B22F3/11—Making porous workpieces or articles
  • B22F3/1121—Making porous workpieces or articles by using decomposable, meltable or sublimatable fillers
  • B22F3/1137—Making porous workpieces or articles by using decomposable, meltable or sublimatable fillers by coating porous removable preforms
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/64—Carriers or collectors
  • H01M4/66—Selection of materials
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/64—Carriers or collectors
  • H01M4/66—Selection of materials
  • H01M4/661—Metal or alloys, e.g. alloy coatings
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/64—Carriers or collectors
  • H01M4/70—Carriers or collectors characterised by shape or form
  • H01M4/76—Containers for holding the active material, e.g. tubes, capsules
  • H01M4/762—Porous or perforated metallic containers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/64—Carriers or collectors
  • H01M4/70—Carriers or collectors characterised by shape or form
  • H01M4/80—Porous plates, e.g. sintered carriers
  • H01M4/808—Foamed, spongy materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
  • B22F2998/10—Processes characterised by the sequence of their steps
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/249921—Web or sheet containing structurally defined element or component
  • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
  • Y10T428/249967—Inorganic matrix in void-containing component
  • Y10T428/24997—Of metal-containing material

Definitions

• the resulting sponge-like porous metal matrix will have substantially spindle-shaped, open pores.
• An electrode utilizing such a matrix of elongated pores may have the capability of a high density of filled active material, but is not always useful to provide optimal conditions in all battery types.
• the invention is directed to the method of producing a strip of an open-cell, three dimensional reticulated sheet of foam having a multitude of pores of rearranged shape, which pores maintain such rearranged shape, the foam strip having a length in the longitudinal direction and a width in the transverse direction, with the length being greater than the width, which method comprises:
• the present invention is also directed to a strip of reticulated foam having a length in the longitudinal direction and a width in the transverse direction, with the length being greater than the width, which foam strip is produced in the longitudinal direction and stretched in the transverse direction in the manner described hereinabove.
• a foam of oval pores which has initially machine produced enhanced tensile strength as determined in the longitudinal direction, may, by stretching to provide at least substantially isotropic diameter pores, have tensile strength that can be at least substantially equalized for both the transverse and longitudinal direction.
• the average number of pores per inch is dictated by application. For instance, for an electrode substrate for a nickel-cadmium battery, it may be desirable to utilize a polymer foam having from about 40 to about 110 pores per inch. For a substrate for an engine piston head, it may be desirable to employ a polymer foam having from about 7 to about 45 pores per inch.
• Foams that are processed to be conductive, which operation could include a heating step, such as for curing a foam which might be coated with a paint composition of a colloidal dispersion of carbon black, are of particular interest in the present invention. These foams typically proceed through a representative process of foam production, foam coating and heating to cure an applied coating. However, it is to be understood that many other processes are contemplated as serviceable in the present invention, e.g., heating of the foam before coating application, as well as coating of the foam by plating, typically without utilizing heating in the plating operation. Moreover in the representative process including foam coating and heating to cure applied coating, the stretching of the foam in the transverse direction will usually be undertaken between foam coating and heating. However, other procedures can be serviceable, e.g., stretching of the foam before coating and heating.
• a strip 12 of porous product is fed from a source not shown over an initial support roll 14 into a coating tank 18.
• the tank 18 is maintained to a level 20 with a coating bath 22.
• the coating bath 22 can be any of a number of coating baths containing liquid composition capable of applying a coating, and advantageously one for preparing an initially conductive foam strip.
• the longitudinal direction of the strip 12 is the direction from left to right of the figure, which can also be the machine produced direction of the strip 12.
• This equipment 26 has a belt 27 which travels around a pair of belt rollers 28, 29.
• the outer surface of the belt 27 carries a series of spikes 30. These spikes 30 puncture the strip 12 along an outer, transverse edge of the coated strip 12. Moreover, by positioning of the spreader equipment 26, the spikes 30 apply a transverse stretch to the coated strip 12.
• the porous product is stretched in a processing manner as depicted in Fig. 1 , i.e., where a coating composition has been applied, or where the porous product is stretched in any other processing manner, e.g., where the coating application and stretching have been done together, it is contemplated that the product can be held in stretched form through a subsequent heating operation.
• the strip 12 can be maintained on stretching apparatus and continue in stretched condition through the oven 33.
• a representative polyurethane foam that has been coated to provide conductivity and the coated foam will be heated such can typically be handled at a temperature within the range of from about 250°F. to about 500°F.
• the heating of the coating can be useful to set the strip 12 in stretched form after it releases from the spreader equipment 26, as by curing crosslinking agents of the coating to set the stretch.
• the coating can be particularly advantageous for holding the strip 12 in stretched form after release from equipment stretching the strip 12. The coating can help provide strength to the final foam product in stretched condition, thereby helping to create a firm set to the stretched foam.
• pyrolysis will be conducted at a temperature in the range from about 500°C to about 900°C for a few minutes, e.g., 1-5 minutes, although longer pyrolysis times such as up to three hours may be used, depending upon the initial matrix material.
• Such procedure can be followed by annealing, using conventional annealing techniques to, for example, improve product ductility. For instance, if the electroplating has been nickel electroplating, annealing can take place in a hydrogen environment at about 800°C to about 1200°C for a few minutes, such as 6-12 minutes, although longer times up to about 30 minutes may be employed.
• Procedures for nickel electroplating of an initially conductive foam, as well as subsequent pyrolysis and annealing have been taught for example in U.S. Patent No. 5,098,544.
• the porous product is an open-cell, reticulated metal sheet
• it can be used for the production of battery electrodes.
• open-cell foam When open-cell foam is used, a fairly uniform plated sheet may be attained (uniformity across the direction of the thickness of the sheet).
• the ratio of plated metal between the cell strands at the surface area of the sheet, and cell strands at the central part of the sheet, may vary. This is expressed as a ratio of the outermost fiber plating deposit thickness, to the innermost fiber plating deposit thickness. This ratio can be termed a deposit thickness ratio, also called a differential thickness ratio or, in either case, the DTR.
• Prepared sheets of reticulated metal foam are contemplated to have a DTR as low as l:l. They have been taught, e.g., in U.S. Patent No. 3,694,325, to have a DTR as small as 1.05:1. However, much greater DTR's, such as up to 4:1 or even 5:1 may be produced.
• EXAMPLE 1 A commercially available soft, open cell foam in strip form, which was grade Z-110 polyurethane foam available from Foamex International, Inc., was used. A sample of this strip, about 6 meters long, was 73 cm. wide and 1.65 cm. in thickness. It had a weight of 50 grams per square meter (g/m 2 ). It was coated in a trough containing a colloidal dispersion of carbon black for purposes of preparing a semi- conductive foam. On removal from the coating trough, the emerging foam strip sample was squeezed by feeding through rollers to remove excess coating composition.
• This resulting foam having initial conductivity, was then electroplated in the continuous plating apparatus of U.S. Patent No. 5,098,544. Electroplating was carried out at a line speed of about 3.5 inches per minute.
• the electroplate bath was a nickel- sulfamate bath maintained at a pH of about 3.7 and a temperature of about 60°C.
• the nickel plated foam was then pyrolyzed at 775°C for 2 minutes in air and annealed at a temperature of 950°C for a time of 7.2 minutes in hydrogen. This removed the polyurethane foam and provided an open-cell metallic nickel foam.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Cell Electrode Carriers And Collectors (AREA)
• Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
• Battery Electrode And Active Subsutance (AREA)
• Powder Metallurgy (AREA)
• Chemically Coating (AREA)
• Laminated Bodies (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=24034174

Family Applications (1)

Country Status (10)

Cited By (1)

Families Citing this family (36)

Citations (4)

Family Cites Families (12)

• 1995
  • 1995-08-04 US US08/511,270 patent/US5738907A/en not_active Expired - Lifetime
• 1996
  • 1996-07-03 TW TW085108051A patent/TW321797B/zh active
  • 1996-07-11 EP EP96923698A patent/EP0843902B1/en not_active Expired - Lifetime
  • 1996-07-11 CN CN96196027A patent/CN1092406C/zh not_active Expired - Fee Related
  • 1996-07-11 WO PCT/US1996/011422 patent/WO1997006570A1/en not_active Ceased
  • 1996-07-11 CA CA002228420A patent/CA2228420A1/en not_active Abandoned
  • 1996-07-11 AT AT96923698T patent/ATE198681T1/de active
  • 1996-07-11 JP JP50843197A patent/JP4046352B2/ja not_active Expired - Fee Related
  • 1996-07-11 DE DE69611526T patent/DE69611526D1/de not_active Expired - Lifetime
  • 1996-07-11 KR KR1019980700790A patent/KR19990036122A/ko not_active Withdrawn

Patent Citations (4)

Also Published As

Similar Documents

Legal Events