US3420714A - Round cells and batteries made therefrom - Google Patents

Round cells and batteries made therefrom Download PDF

Info

Publication number
US3420714A
US3420714A US465319A US3420714DA US3420714A US 3420714 A US3420714 A US 3420714A US 465319 A US465319 A US 465319A US 3420714D A US3420714D A US 3420714DA US 3420714 A US3420714 A US 3420714A
Authority
US
United States
Prior art keywords
cell
coating
seal
round
plastics material
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US465319A
Other languages
English (en)
Inventor
Geoffrey Peter Knight
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
WER MVL 1998 Ltd
Original Assignee
Ever Ready Co Great Britain Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ever Ready Co Great Britain Ltd filed Critical Ever Ready Co Great Britain Ltd
Application granted granted Critical
Publication of US3420714A publication Critical patent/US3420714A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/172—Arrangements of electric connectors penetrating the casing
    • H01M50/174—Arrangements of electric connectors penetrating the casing adapted for the shape of the cells
    • H01M50/182—Arrangements of electric connectors penetrating the casing adapted for the shape of the cells for cells with a collector centrally disposed in the active mass, e.g. Leclanché cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M6/00—Primary cells; Manufacture thereof
    • H01M6/04—Cells with aqueous electrolyte
    • H01M6/06—Dry cells, i.e. cells wherein the electrolyte is rendered non-fluid
    • H01M6/08—Dry cells, i.e. cells wherein the electrolyte is rendered non-fluid with cup-shaped electrodes

Definitions

  • a commonly used type of galvanic cell comprises a zinc can (soluble electrode), a coaxial carbon rod (insoluble electrode), and a bobbin of a depolarizer which fits over the carbon rod and is only prevented from contacting the inner wall of the can by a paper separator.
  • the top of the carbon rod projects somewhat above the top of the can and is provided with a flanged metal cap which is push-fitted thereonto.
  • a bitumastic seal of considerable thickness closes the head space in the can to prevent loss of electrolyte and escape of moisture. Since the seal adheres to the can severe increases in pressures in the cell may fracture the bitumastic seal so that the depolarizer is no longer prevented from drying out.
  • a disability of such cells is the possibility of seepage of electrolyte through the top of the cell particularly during periods of rapid discharge of the cell.
  • the electrolyte makes the can wall sufficiently porous to cause seepage through the wall and eventually, by chemical action, binds the cell to the article, e.g. a flash light casing in which it has been used.
  • a cardboard washer is incorporated thereabove in the head-space, and to form a seal at the top of the can the latter has been provided with a cardboard jacket, the top of which is folded into a lock joint made between the top of the can and a metal annulus which bears on the radial flange on the cap of the carbon rod and is electrically insulated therefrom by a cardboard washer.
  • Such cells are relatively expensive to produce and the formation of the lock joint at the top of the cells involves use of a zinc can of sufficient height to produce the metal to be used in the lock joint.
  • the main object of the present invention is to produce an improved leak proof cell.
  • a galvanic dry cell comprising a can (soluble electrode), a coaxial carbon rod (insoluble electrode), a depolarizer bobbin about the rod and a separator between the bobbin and the can wall, the rod carrying a metal cap, is characterized by a chamber above the depolarizer and another located by a wall formation near the top of the can.
  • the invention also comprises a leak proof cell constructed as just described encapsulated by injection moulding methods at relatively low temperatures and pressures using a synthetic plastics material which is sufliciently mobile at low temperature so that low moulding pressures and temperatures are used to effect encapsulation and when set has suflicient coherence at normal, even tropical, temperatures to retain the pristine seal.
  • Suitable synthetic plastic materials for use according to the invention in making a leak proof cell are low molecular weight polyethylene, they are mobile at quite low temperatures (130 C.l C.) and on setting have sufii cient coherence to retain the required hermetic seal over the cell to prevent loss of moisture from the depolarizer.
  • nylon as well as a copolymer of polyvinyl acetate and polyethylene (Elvax) or mixtures of polyethylene with parafiln wax, for example, 50% by weight of polyethylene and 50% by weight of paraffin wax, can be injection moulded onto dry cells and batteries comprising the dry cells using low temperatures, for example, to C., and pressures of the order of 100 lbs. to lbs. per sq. in. not exceeding, for example, -200 lbs. per sq. in. These low pressures compare with pressures of the order of 20,000 lbs. per sq. in. which are conventionally employed.
  • the injection moulding machine which may be water cooled for example, has a high thermal capacity so that coating materials mobile at temperatures higher than a battery or round cell could withstand if exposed to such temperatures in an oven for example, can be used because these coating materials rapidly give up their heat during the moulding process before they can injure the cell or battery.
  • synthetic plastics materials are chosen so that they are injection moulded onto the cell under conditions which in no way harm the cell.
  • FIGURE 1 is an elevation, partly in section, of a round cell constructed in accordance with the invention
  • FIGURE 2 is an underside plan view of the round cell
  • FIGURE 3 is a plan view of the top of the round cell
  • FIGURE 4 shows an assembled round cell in a mould (shown in section) ready for coating by injection moulding.
  • FIGURES l, 2 and 3 of the drawings Referring first to FIGURES l, 2 and 3 of the drawings.
  • a round cell of the Leclanche type comprising a zinc can 1 as the soluble electrode and a coaxial carbon rod 2, capped by a brass cap 3, as the insoluble electrode.
  • the zinc can 1 contains a conventional bobbin 4 of depolarizer and electrolyte, above which is a cardboard washer 5 located on the carbon rod 2 and of a diameter to engage the inner face of the can 1.
  • the zinc can 1 is formed near its upper end with an inwardly directed circumferential groove 6 in which groove rests a spacing washer 8 formed from an electrically insulating material, for example, polystyrene, the upper end of the can wall is turned inwardly onto the washer 8 to hold it firmly in position.
  • the washer is designed to remain rigid and intact during the moulding of a plastic coating onto the round cell to hermetically seal the cell as hereinafter described.
  • the washers 5 and 8 define an expansion chamber 9, in the upper part of the can for reception of any gas and/ or electrolyte exuded by the depolarizer during rapid discharge of the cell and during production of a coating on the cell, as hereinafter described.
  • the cell constructed according to the invention and prepared for coating does not include the conventional bitumastic seal and accordingly the cell is lighter than a corresponding conventional dry cell.
  • the round cell so constructed is hermetically sealed by a coating 10 which coating envelops the can wall and extends under the bottom wall 11 of the can 1 to a limited extent, as shown in FIGURE 1, as well as over the spacing washer 8 and over the flange 12 of the cap 3, the overlap of the coating on the bottom 11 of the can 1 being such that a central part is uncovered to have an area for electrical connection to be made thereto, for example with cap 3 of another cell arranged in series relation.
  • a coating 10 which coating envelops the can wall and extends under the bottom wall 11 of the can 1 to a limited extent, as shown in FIGURE 1, as well as over the spacing washer 8 and over the flange 12 of the cap 3, the overlap of the coating on the bottom 11 of the can 1 being such that a central part is uncovered to have an area for electrical connection to be made thereto, for example with cap 3 of another cell arranged in series relation.
  • the coating 10 preferably goes over and underneath the flange 12 on the brass cap 3 so that the flange becomes incorporated in the coating but does not pass between the spacing washer 8 and the carbon rod. Accordingly the coating 10 hermetically seals the cell and insulates the upper end 6 of the zinc can 1 from the carbon rod 2 and the brass cap 3.
  • the coating is formed from a synthetic plastics material, for example polyethylene, which is inert and impervious to electrolyte so that no seepage of electrolyte can occur between the cap flange 12 and the upper end 6 of the can 1.
  • the moulded coating is in intimate contact with the area of the round cell which it covers due to the tension in the coating inherent in the method of forming the coating and the ensuing contraction of the coating in situ.
  • the coating is not truly adhesive and experiments have shown that if the coating is slit parallelly to the carbon rod the coating opens away from the slit.
  • the method of forming the coating i.e. by an injection moulding procedure, is such that intimate contact with the round cell wall that it closely follows even microeccentricities in the wall surface, thus the coating is to be differentiated from a round cell enclosed in a preformed sheath of synthetic plastics material where there is a definite gap between the zinc bucket 1 and the sheath.
  • a round cell fully assembled, as already described, is placed in a mould formed in two separate hollow parts 13 and 14 capable of being clamped together to form a mold.
  • the bottom 11 of the zinc container 1 is supported in the mould part 13 by a coaxial boss 15 which covers the central part of the bottom 11 to prevent the central part being coated.
  • the other end of the round cell is engaged in the other mould part 14 by coaxial recess 16 which receives the cap 3 and prevents molten plastics material from forming a coating on the cap 3.
  • Molten synthetic plastics material is injected into the mould from a conventional injection moulding machine (not shown) through an inlet 17 and delivers the plastics material through radial inlets 18 of which two are shown, into a moulding cavity 19 enveloping the whole of the cell except the part abutting the boss 15.
  • the invention has been exemplified by reference to moulding a coating onto a single round cell, it will be understood that by suitably designing the moulds, two or more cells constructed according to the invention connected in parallel may be encapsulated to constitute an hermetically sealed battery, indeed any prescribed shape of the battery can :be moulded to include a plurality of interconnected cells, and it is to be understood that the present invention comprehends electrically connected batteries encapsulated together in the manner described.
  • a false bottom plate may be added to each round cell and maintained in position by the coating, such plate may be embossed to ensure intimate contact between adjacent cells.
  • the leak proof battery is economically achieved; the complex interlocking equipment necessary to produce the conventional lock seam at the top of the can is not required, and the height of the can is at a minimum because of the absence of the conventional bitumastic seal, and accordingly a considerable saving in the amount of zinc required in forming the can is obtained.
  • a galvanic dry cell comprising a can as the soluble electrode, a carbon rod as the insoluble electrode, a depolarizer bobbin about the rod and a separator between the bobbin and the can wall, the rod carrying a flanged metal cap, with a chamer above the depolarizer defined by a first insulating washer just above the depolarizer and a second insulating washer located by a wall formation near to the top of the can, and an injection moulded coating of synthetic plastics material encapsulating the engaging can and including a seal between the can rim and engaging said metal cap flange and also including a clamping flange overlying the marginal area of the base of the can, said seal and said clamping flange being integrally joined by a cylindrical portion of the coating which portion is in intimate contact with the whole cylindrical wall of the can including the region of said wall formation.
  • a process for producing a galvanic dry cell having as its main components a can as the soluble electrode, a carbon rod as the insoluble electrode, the carbon rod having a flanged metal cap, a depolarizer bobbin about the rod, and a separator between the bobbin and the can wall, characterized by the step of forming in one operation an integral coating which encapsulates the cell and which coating includes a seal between the can rim and said metal cap flange and also includes a clamping flange overlying the marginal area of the base of the can, said operation being effected by supporting the cell in a mould of capacity suflicient to allow the formation of the said coating around the cell, and injecting a synthetic plastics material at a temperature below C. and at a pressure below 200 p.s.i. into the mould to form the casing around the cell while cooling the mould, said plastics material being selected so as to be mobile at the said low temperatures.
  • plastics material is a mixture of 50% by weight of polyethylene and 50% by weight of parafiin wax.
  • the synthetic plastics material is a copolymer of polyvinyl acetate and polyethylene.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Sealing Battery Cases Or Jackets (AREA)
  • Primary Cells (AREA)
US465319A 1964-06-24 1965-06-21 Round cells and batteries made therefrom Expired - Lifetime US3420714A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB26212/64A GB1116593A (en) 1964-06-24 1964-06-24 Improvements in or relating to cylindrical cells and batteries made therefrom

Publications (1)

Publication Number Publication Date
US3420714A true US3420714A (en) 1969-01-07

Family

ID=10240108

Family Applications (1)

Application Number Title Priority Date Filing Date
US465319A Expired - Lifetime US3420714A (en) 1964-06-24 1965-06-21 Round cells and batteries made therefrom

Country Status (7)

Country Link
US (1) US3420714A (de)
JP (1) JPS4843690B1 (de)
BE (1) BE665892A (de)
DE (1) DE1596044A1 (de)
DK (1) DK121389B (de)
GB (1) GB1116593A (de)
SE (1) SE327245B (de)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3524770A (en) * 1966-07-11 1970-08-18 Servel Inc Dry cell seal
US3607412A (en) * 1967-11-27 1971-09-21 Lucas Industries Ltd Battery plate grids
US3622392A (en) * 1968-11-01 1971-11-23 Esb Inc Organic depolarized cell construction
US3627586A (en) * 1968-12-12 1971-12-14 Accumulateurs Fixes Sealed cylindrical electrochemical cell
US3891463A (en) * 1972-12-21 1975-06-24 Kapsch Telephon Telegraph Leak-proof galvanic cell
US3898104A (en) * 1971-01-28 1975-08-05 Costa Joao Baptista Pimenta Da Cylindrical electrical batteries
US4048401A (en) * 1975-01-09 1977-09-13 Gte Laboratories Incorporated Hermetically sealed primary electrochemical cell and a method for its production
US4087595A (en) * 1973-04-23 1978-05-02 P.R. Mallory & Co. Inc. Multi-cell battery and method of making
US4254192A (en) * 1979-11-23 1981-03-03 The International Nickel Company, Inc. Primary galvanic cell
US20030173709A1 (en) * 2000-10-20 2003-09-18 Yoshinori Iwaizono Method and device for forming outer packaging body of product
US20130071725A1 (en) * 2011-09-19 2013-03-21 Stmicroelectronics (Tours) Sas Method of encapsulating an electrical energy accumulation component and battery

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5410296U (de) * 1977-06-22 1979-01-23

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2427561A (en) * 1944-09-15 1947-09-16 Bright Star Battery Company Flashlight battery with plastic casing
US2450813A (en) * 1945-07-31 1948-10-05 Olin Ind Inc Leakproof dry cell
US2571732A (en) * 1948-05-28 1951-10-16 Burndept Ltd Primary electric cell
US2923757A (en) * 1957-03-27 1960-02-02 Mallory & Co Inc P R Dry cell
US3278339A (en) * 1964-04-20 1966-10-11 Union Carbide Corp Primary dry cells
US3311690A (en) * 1963-03-13 1967-03-28 Continuous Molding Corp Injection molding method for encapsulating metal objects

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2427561A (en) * 1944-09-15 1947-09-16 Bright Star Battery Company Flashlight battery with plastic casing
US2450813A (en) * 1945-07-31 1948-10-05 Olin Ind Inc Leakproof dry cell
US2571732A (en) * 1948-05-28 1951-10-16 Burndept Ltd Primary electric cell
US2923757A (en) * 1957-03-27 1960-02-02 Mallory & Co Inc P R Dry cell
US3311690A (en) * 1963-03-13 1967-03-28 Continuous Molding Corp Injection molding method for encapsulating metal objects
US3278339A (en) * 1964-04-20 1966-10-11 Union Carbide Corp Primary dry cells

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3524770A (en) * 1966-07-11 1970-08-18 Servel Inc Dry cell seal
US3607412A (en) * 1967-11-27 1971-09-21 Lucas Industries Ltd Battery plate grids
US3622392A (en) * 1968-11-01 1971-11-23 Esb Inc Organic depolarized cell construction
US3627586A (en) * 1968-12-12 1971-12-14 Accumulateurs Fixes Sealed cylindrical electrochemical cell
US3898104A (en) * 1971-01-28 1975-08-05 Costa Joao Baptista Pimenta Da Cylindrical electrical batteries
US3891463A (en) * 1972-12-21 1975-06-24 Kapsch Telephon Telegraph Leak-proof galvanic cell
US4087595A (en) * 1973-04-23 1978-05-02 P.R. Mallory & Co. Inc. Multi-cell battery and method of making
US4048401A (en) * 1975-01-09 1977-09-13 Gte Laboratories Incorporated Hermetically sealed primary electrochemical cell and a method for its production
US4254192A (en) * 1979-11-23 1981-03-03 The International Nickel Company, Inc. Primary galvanic cell
US20030173709A1 (en) * 2000-10-20 2003-09-18 Yoshinori Iwaizono Method and device for forming outer packaging body of product
US6881371B2 (en) * 2000-10-20 2005-04-19 Matsushita Electric Industrial Co., Ltd. Method for forming outer packaging body of product
CN100456528C (zh) * 2000-10-20 2009-01-28 松下电器产业株式会社 产品的保护体形成方法及其装置
US20130071725A1 (en) * 2011-09-19 2013-03-21 Stmicroelectronics (Tours) Sas Method of encapsulating an electrical energy accumulation component and battery
US8852481B2 (en) * 2011-09-19 2014-10-07 Stmicroelectronics (Tours) Sas Method of encapsulating an electrical energy accumulation component

Also Published As

Publication number Publication date
DE1596044A1 (de) 1971-04-01
BE665892A (de) 1965-12-24
GB1116593A (en) 1968-06-06
SE327245B (de) 1970-08-17
DK121389B (da) 1971-10-11
JPS4843690B1 (de) 1973-12-20

Similar Documents

Publication Publication Date Title
US3420714A (en) Round cells and batteries made therefrom
US5562741A (en) Method of making a bipolar battery housing
US3855000A (en) Air depolarization primary cell and process for production thereof
US5227261A (en) Cylindrical electrochemical cells with a diaphragm seal
US6017653A (en) Method of manufacturing modular molded components for a bipolar battery and the resulting bipolar battery
US4804593A (en) Enclosed cell having safety valve mechanism and fabricating method of the same
US4076908A (en) Pole bolt seal for storage batteries
US2758259A (en) Electrolytic capacitor device
US3511906A (en) Process for producing a pressure-resistant,edge-sealing mounting for porous discs
US3692587A (en) Multicell storage battery
US2450813A (en) Leakproof dry cell
EP0246590B1 (de) Geschlossene Zelle mit Sicherheitsventilanordnung und Verfahren zu ihrer Herstellung
US4048406A (en) Electrode for a rechargeable electrochemical current source, and method of making same
US3449171A (en) Method of making an encapsulated dry battery
US3644149A (en) Battery terminal construction and method for forming battery terminals
US2903499A (en) Primary battery
US2684397A (en) Battery and method of making same
US2244016A (en) Process for manufacturing dry cells
US3877992A (en) Primary dry cell with fail-safe vent
US4053686A (en) Epoxy sealed lead battery probe
US3040117A (en) Process for manufacturing primary dry cells
KR970007516B1 (ko) 사출성형된 마개
US3575724A (en) Cylindrical primary dry cells
US4010537A (en) Epoxy sealed lead battery probe and method for inserting same
US2419244A (en) Method of manufacturing dry cells