Method and apparatus for manufacturing battery vents and vented batteries

• US 4,256,813 A
• Filed: 01/21/1980
• Issued: 03/17/1981
• Est. Priority Date: 01/24/1977
• Status: Expired due to Term

• Current Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Original Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Inventors: Kniazzeh, Alfredo G.
• Primary Examiner(s): Walton, Donald L.
• Application Number:
  US06/113,551
• Time in Patent Office: 421 Days
• Field of Search: 429/86, 429/152, 429/162, 29/623.3, 156/276, 156/306.3, 156/309.9, 427/121, 427/411, 428/233, 428/342, 428/478.8, 428/479.6, 428/496, 428/530
• US Class Current: 429/86
• CPC Class Codes: H01M 50/30 Arrangements for facilitating escape of gases
• CPC Class Codes: H01M 50/394 Gas-pervious parts or elements
• CPC Class Codes: H01M 6/12 with flat electrodes
• CPC Class Codes: H01M 6/48 with bipolar electrodes
• CPC Class Codes: Y10T 29/49112 including laminating of indefinite length material

Abstract

A vent for thin, flat laminar batteries comprising a paper strip enclosed along its length by a gas-permeable, liquid impermeable thermoplastic composition. One or more of the vents can be incorporated into a frame structure which also serves to provide internal and external sealing. For this purpose, the vents are sealed to frames comprising closed loops of thermoplastic material, dimensioned to correspond to the external and internal dimensions of the battery. Methods of making vents comprising the steps of laminating paper with a thermoplastic material and forming the laminate into thermoplastic tubes filled with a paper core.

Claims

1. A battery vent, comprising an elongated tube of liquid impervious, hydrogen permeable thermoplastic material filled with a thin, narrow elongated strip of paper, said tube being open at at least one end.

2. A battery vent, comprising a strip of paper encased on at least four sides in a sheath of liquid impervious, hydrogen permeable thermoplastic resin and having at least one end exposed.

3. A battery vent, comprising a composite strip of thermoplastic resin and paper having at least one external paper surface and at least one external resin surface, said external resin surface having a substantially greater area than said external paper surface.

4. The battery vent of claim 3, in which said composite strip comprises a thin, narrow elongated strip of paper laminated between two thin narrow elongated strips of thermoplastic resin.

5. The battery vent of claim 3, in which said composite strip comprises an elongated tube of liquid impervious, hydrogen permeable material filled with an elongated strip of paper.

6. A battery vent, comprising an elongated tube of vinyl resin filled with an elongated strip of paper.

7. The battery vent of claim 6, in which said vinyl resin is a copolymer of vinyl chloride and vinyl acetate.

8. The method of making battery vent stock, comprising the steps of laminating two sheets of liquid impervious, hydrogen permeable thermoplastic resin to opposite sides of a sheet of paper, and slitting said laminated sheet into narrow elongated strips.

9. The method of making battery vent stock, comprising the steps of laminating two sheets of liquid impervious, hydrogen permeable thermoplastic resin to a sheet of paper under sufficient heat and pressure to establish a bond sufficient to allow the laminate to be handled as a unit, slitting the laminate into thin elongated strips, and heating the strips under pressure to fuse the plastic strips on either side of each paper strip together into a paper filled plastic tube.

10. The method of making vented battery frame stock, comprising the steps of feeding a pair of spaced parallel elongated plastic tubes each filled with a paper strip between confronting sheets of thermoplastic sheet material through a pair of heated nip rolls to adhere the confronting thermoplastic sheets together and thereby enclose the tubes, and cutting apertures through the adhering sheets between the tubes to form a vented ladder of battery frames.

11. The method of making vented battery frame and separator subassembly stock, comprising the steps of feeding a pair of spaced parallel elongated plastic tubes each filled with a paper strip between confronting sheets of thermoplastic sheet material through a pair of heated nip rolls to adhere the confronting thermoplastic sheets together and thereby enclose the tubes, cutting windows through the adhering sheets between the tubes to form a vented ladder of battery frames, and tacking a cellophane separator over each of said windows with heat and pressure to form a temporary bond permitting the stock to be handled as a unit.

12. The method of making vented battery frames comprising the steps of feeding a pair of spaced parallel elongated plastic tubes each filled with a paper strip between confronting sheets of thermoplastic sheet material through a pair of heated nip rolls to adhere the confronting thermoplastic sheets together and thereby enclose the tubes, cutting windows through the adhering sheets between the tubes to form a vented ladder of battery frames, adhering a cellophane separator over each of said windows, and cutting said adhering sheets and the tubes enclosed thereby between said separators to form vented frame and separator subassemblies.

13. The method of making vented battery frame stock, comprising the steps of laminating an elongated plastic tube filled with a paper strip between confronting sheets of thermoplastic sheet material under heat and pressure to adhere the confronting thermoplastic sheets together and thereby enclose the tube, said tube being located closer to one edge of said confronting strips than to the other in a direction normal to the direction of elongation of said tube, and cutting windows through the adhering sheets between the tube and the edge farthest from the tube to form a vented ladder of battery frames.

14. The method of making vented battery frame and separator subassembly stock, comprising the steps of laminating at least one tube filled with a paper strip between confronting sheets of thermoplastic sheet material by adhering the confronting thermoplastic sheets together to thereby enclose the tube, cutting windows through the adhering sheets alongside the tube to form a vented ladder of battery frames, and adhering a separator over each of said windows to form a bond permitting the stock to be handled as a unit.

15. The method of making vented battery frames, comprising the steps of laminating an elongated plastic tube filled with a paper strip between confronting sheets of thermoplastic sheet material near one edge of said sheets by adhering the confronting thermoplastic sheets together to thereby enclose the tube, cutting windows through the adhering sheets in regions spaced from the paper to form a vented ladder of battery frames, adhering a separator over each of said windows, and cutting said adhering sheets and the tube enclosed thereby between said separators to form vented frame and separator subassemblies.

16. A battery frame construction adapted to permit electrolyte migration between electrodes in a cell within a battery and to permit venting of gas produced within the battery, comprising a closed loop of gas-permeable, liquid-impermeable material, said loop defining an open area within the loop and an outer periphery having dimensions substantially corresponding to the outer periphery of the battery;

and at least one vent comprising a paper strip embedded in said loop and extending along one side at least to said outer periphery.

17. The frame construction of claim 16 wherein the vent is positioned between and sealed to a pair of said loops.

18. The frame construction of claim 16 which includes at least two of said battery vents.

19. The method of making vented battery frame stock, comprising the steps of laminating at least one elongated strip of battery vent stock between confronting sheets of thermoplastic sheet material by adhering the confronting thermoplastic sheets together to thereby enclose the vent stock, and cutting windows through the adhering sheets in regions spaced from the vent stock to form a vented ladder of battery frames.

20. The method of making vented battery frame and separator subassembly stock, comprising the steps of laminating at least one strip of battery vent stock between confronting sheets of thermoplastic sheet material by adhering the confronting thermoplastic sheets together to thereby enclose the strip of vent stock, cutting windows through the adhering sheets alongside the strip to form a vented ladder of battery frames, and adhering a separator over each of said windows to form a bond permitting the stock to be handled as a unit.

21. The method of making vented battery frames comprising the steps of laminating at least one elongated strip of vent stock between confronting sheets of thermoplastic sheet material by adhering the confronting thermoplastic sheets together to thereby enclose the strip of vent stock, cutting windows through the adhering sheets alongside the strip to form a vented ladder of battery frames, adhering a separator over each of said windows, and cutting said adhering sheets and the strip of vent stock enclosed thereby between said separators to form vented frame and separator subassemblies.

22. A battery frame construction adapted to permit electrolyte migration between electrodes in a cell within a battery and to permit venting of gas produced within the battery, comprising two closed loops each comprising a flat substrate with both surfaces comprising an adhesive composition, said loops defining an open area within the loops and an outer periphery having dimensions substantially corresponding to the outer periphery of the battery;

at least one narrow elongated paper strip extending alongside said open area between said loops at least to said outer periphery and being sealed to and between said loops;

said loops being sealed together.

23. A battery frame construction adapted to permit electrolyte migration between electrodes in a cell within a battery and to permit venting of gas produced within the battery, comprising two closed loops each comprising a flat substrate with both surfaces comprising an adhesive composition, said loops defining an open area within the loops and an outer periphery having dimensions substantially corresponding to the outer periphery of the battery;

at least one battery vent extending alongside said open area between said outer periphery and said open area at least to said outer periphery and being sealed to said loops; and

an electrolyte-permeable membrane sealed to one of said loops to cover said open area, said battery vent comprising a paper strip.

24. A battery frame construction adapted to permit electrolyte migration between electrodes in a cell within a battery and to permit venting of gas produced within the battery, comprising two closed loops each comprising a flat substrate with both surfaces comprising an adhesive composition, said loops defining an open area within the loops and an outer periphery having dimensions substantially corresponding to the outer periphery of the battery;

at least one battery vent extending between said loops alongside said open area at least to said outer periphery and spaced from said open area and said outer periphery;

said vent being sealed to said loops; and

an electrolyte-permeable membrane sealed to at least one of said loops to cover said open area, said battery vent comprising a paper strip enclosed along its length by a gas-permeable, liquid-impermeable plastic composition.