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US4963161A Expired / Lapsed US ⏱️ 0.0 years remaining

Non-aqueous alkali battery having an improved cathode

Assignee: Nokia Bell Labs
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Filing: 1989-07-10
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Granted: 1990-10-16
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Expires: 2009-07-10
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Abstract

Abstract This invention relates to a process of fabricating a rechargeable non-aqueous cell and to a cell produced by the process. The cell includes a unique laminated cathode structure. Other structural features of the non-aqueous cell including anode, non-aqueous electrolyte and separator, are generally conventional. The novel cathode is composed of a current collector consisting of an unperforated metal foil to which are bonded mats of cathode active material, selected from transition-metal chalcogenides. In the process of forming the cathode, a non-perforated metal foil, such as aluminum, is coated with a layer of bonding polymer and after the mats of cathode-active material, such as niobium triselenide, are placed on both sides of the metal foil, the composite is compacted, preferably by passing between rollers. Electronic conduction is enhanced by either admixing carbon black with the polymer or coating that surface of the mats which is to be in contact with the metal foil, with a thin layer of carbon black. This design results in cells which show a distinct improvement in energy at higher rate discharges, e.g. at 3-4A, or at lower temperatures, e.g. -20° C., lower cost and weight than cells with conventional cathode collector having screen or grid of expanded metal, e.g. Ni, and are expected to ameliorate internal shorts resulting from the use of ex-met grids.

Inventors

  • 👤 Ignacio Chi
  • 👤 Wei-Chou Fang

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 23:30
CPC Classifications
H; H01; H01M; H01M10/00; H01M10/05; H01M4/00; H01M4/02; H01M4/62; H01M4/621; H01M4/64; H01M4/66; H01M4/661; H01M4/663; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49108; Y10T29/49115

Claims Analysis

Total Claims: 22
Claim 1
Independent Claim 199 words
A process of production a non-aqueous secondary cell comprising an alkali metal anode electrode, a cathode electrode with cathode active material, a separator, and an electrolyte comprising an organic solvent having an alkali metal dissolved therein, said cathode active material comprisng at least one chaloceginde material selected from the group consisting of NbSe 2 , NbSe 3 , NbS 3 , MoS 2 , TiS 2 , TiS 3 , TaSe 3 , TaS 2 , V 6 O 13 , CoO 2 and MoO 2 said process including the step of assembling the anode electrode, the cathode electrode, the separator and the electrolyte to form a non-aqueous secondary cell, wherein said positive electrode is produced by bonding mats of positive electrode active material to opposite surfaces of a metal foil acting as a current collector, the metal being chemically inert under operating conditions of the cell, said bonding including coating said opposite surfaces of the metal foil with a layer of a bonding polymer, placing mats of positive electrode active material in contact with said coated surfaces of the foil so as to form a metal foil and mats composite, and compacting the composite to a desired thickness.
Claim 2
Dependent Claim 199 words
A process of production a non-aqueous secondary cell comprising an alkali metal anode electrode, a cathode electrode with cathode active material, a separator, and an electrolyte comprising an organic solvent having an alkali metal dissolved therein, said cathode active material comprisng at least one chaloceginde material selected from the group consisting of NbSe 2 , NbSe 3 , NbS 3 , MoS 2 , TiS 2 , TiS 3 , TaSe 3 , TaS 2 , V 6 O 13 , CoO 2 and MoO 2 said process including the step of assembling the anode electrode, the cathode electrode, the separator and the electrolyte to form a non-aqueous secondary cell, wherein said positive electrode is produced by bonding mats of positive electrode active material to opposite surfaces of a metal foil acting as a current collector, the metal being chemically inert under operating conditions of the cell, said bonding including coating said opposite surfaces of the metal foil with a layer of a bonding polymer, placing mats of positive electrode active material in contact with said coated surfaces of the foil so as to form a metal foil and mats composite, and compacting the composite to a desired thickness.
Claim 3
Dependent Claim 36 words
The process of claim 1 in which an electronic conduction path between the metal foil and the cathode active material is enhanced by incorporation powdered conductive material between the metal foil and the cathode active material.
Claim 4
Dependent Claim 31 words
The process of claim 2 in which the conductive material is carbon black included within a range of from 0 to 20 wt.%, based on the total wright of the cathode.
Claim 5
Dependent Claim 31 words
The process of claim 2 in which the conductive material is carbon black included within a range of from 0.5 to 5 wt.%, based on the total weight of the cathode.
Claim 6
Dependent Claim 32 words
The process of claim 2 in which the conductive material is carbon black included within a range of from 1 to 3 wt.% , based on the total weight of the cathode.
Claim 7
Dependent Claim 36 words
The process of claim 2 in which, prior to placing the mats onto the foil, that side of each mat whi is to be bonded to the foil is coated with a layer of carbon black.
Claim 8
Dependent Claim 22 words
The process of claim 6 in which said bonding polymer comprises a solution of 1 weight percent of EPDM (ethylene/propylene/diene-terpolymer) in cyclohexane.
Claim 9
Dependent Claim 31 words
The process of claim 1 in which said coating step is effected by coating both of said surfaces of the foil with a slurry of EPDM (ethylene/propylene/diene-terpolymer), carbon black and cyclohexane.
Claim 10
Dependent Claim 23 words
The process of claim 8 in which said slurry has an approximate compostion of 2 EPDM/4 carbon black/94 cyclohexane, all in weight percent.
Claim 11
Dependent Claim 17 words
The process of claim 1 in which the compacted composite is dried to remove any residual solvent.
Claim 12
Dependent Claim 28 words
The process of claim 1 in which the amount of polymer in the cathode ranges from 0.1 to 15 wt.%, based on the total weight of the cathode.
Claim 13
Dependent Claim 28 words
The process of claim 1 in which the amount of polymer in the cathode ranges from 0.1 to 1 wt.%, based on the total weight of the cathode.
Claim 14
Dependent Claim 28 words
The process of claim 1 in which the amount of polymer in the cathode ranges from 0.3 to 0.5 wt.%, based on the total weight of the cathode.
Claim 15
Dependent Claim 17 words
The process of claim 1 in which said compacting is effected by passing the composite between rollers.
Claim 16
Dependent Claim 26 words
The process of claim 1 in which said alkali metal is selected from the group consisting of lithium, sodium, potassium, rubidium and cesium and alloys thereof.
Claim 17
Dependent Claim 12 words
The process of claim 1 in which said alkali metal comprises lithium.
Claim 18
Dependent Claim 15 words
The process of claim 1 in which said cathode active material is NbSe 3 .
Claim 19
Dependent Claim 30 words
The process of claim 1 in which said metal foil comprise a metal selected from a group consisting of aluminum, magnesium, titanium, zinc, lead, iron, nickel, copper and alloys thereof.
Claim 20
Dependent Claim 12 words
The process of claim 1 in which said metal foil is aluminum.
Claim 21
Dependent Claim 46 words
The process of claim 1 in which said alkali metal is lithium, said cathode active material is NbSe 3 , and said metal foil is aluminum, and said bondig comprises coating opposite surfaces of the foil with a slurry of EDPM (ethylene/propylene/diene-terpolymer), carbon black and cyclohexane.
Claim 22
Dependent Claim 23 words
The process of claim 19 in which said slurry has an approximate composition of 2 EPDM/4 carbon black/94 cyclohexane, all in weight percent.

References Cited (Backward Citations)

US3864167A Cited
US4091191A Cited
US4740433A Cited
US4753859A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-10-15 1994-04-16 1994-10-16 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-10-15 1998-04-16 1998-10-16 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-10-15 2002-04-16 2002-10-16 $7700.00 Window Closed / Lapsed

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