Method for manufacturing battery vents and vented batteries

• US 4,254,191 A
• Filed: 11/18/1977
• Issued: 03/03/1981
• 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): Drummond, Douglas J.
• Application Number:
  US05/852,920
• Time in Patent Office: 1,201 Days
• Field of Search: 156/253, 156/306, 429/86, 429/139, 429/126, 429/127, 29/623.4, 29/623.5, 29/623.2, 29/623.3, 429/152, 429/162
• US Class Current: 429/162
• 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 156/1057 Subsequent to assembly of laminae
• CPC Class Codes: Y10T 29/4911 including sealing
• CPC Class Codes: Y10T 29/49114 including adhesively bonding

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 flat laminar battery comprising a contiguous stack of laminar cells electrically connected in series by conductive plastic intercell connectors and terminated by conductive plastic current collectors;

said battery further comprising thermoplastic frames of liquid impermeable, gas permeable material, said frames being formed with central openings to receive active components of said cells;

said frames being located between and separating said intercell connectors and said current collectors;

said frames, said intercell connectors and said current collectors being sealed together at their outer peripheries only to provide a liquid impervious enclosure for said cells; and

at least one elongated strip of paper embedded in one of said frames and entirely surrounded along its length by liquid impermeable, gas permeable material, said strip extending along a region within said sealed outer periphery through said sealed outer periphery to at least one end exposed to the atmosphere.

2. In the method of making a vented laminar battery of the type comprising laminar cells chemically isolated and electrically connected in series by conductive plastic intercell connectors and terminated by conductive plastic current collectors laminated to thin metal external terminal sheets, in which the intercell connectors and current collectors are interdigitated with thermoplastic frames formed with central openings to receive wet active cell components, the steps of embedding at least one strip of paper in at least one of said frames between said opening and one edge of said frame with at least one end of said strip exposed, and sealing said cells by heating the edges of said frames outside of said strip except at the ends of said strip such that the major portion of the length of said strip is inside of the seal but embedded in a liquid-impermeable, gas-permeable matrix of thermoplastic material.

3. The method of claim 2, further comprising the preliminary step of encasing said strip in a tube of gas-permeable, liquid-impermeable material, and in which said step of embedding said strip in said frame is carried out by laminating said strip between two laminar elements of said frame to form an integral vented frame.

4. The method of claim 2, in which said cells are sealed under vacuum.

5. The method of claim 4, in which pressure is applied at least to the edges of the battery while heating, and in which said vacuum is established before said heat and pressure are applied.

6. The method of claim 3, in which said cells are sealed under vacuum.

7. The method of claim 6, in which pressure is applied at least to the edges of the battery while heating, and in which said vacuum is established before said heat and pressure are applied.

8. In the method of making a vented laminar battery of the type comprising laminar cells chemically isolated and electrically connected in series by conductive plastic intercell connectors and terminated by conductive plastic current collectors laminated to thin metal external terminal sheets, in which the intercell connectors and current collectors are interdigitated with thermoplastic frames formed with central openings to receive wet active cell components, the steps of embedding at least one strip of paper in a liquid-impermeable, gas-permeable matrix of thermoplastic material in said battery between said openings and the edges of said frames with at least one end of said strip exposed, and sealing said cells by heating the edges of said frames outside of said strip except at the ends of said strip such that the major portion of the length of said strip is inside of the seal but embedded in a liquid-impermeable, gas-permeable matrix of thermoplastic material.

9. The method of claim 8, further comprising the preliminary step of encasing said strip in a tube of gas-permeable, liquid-impermeable material, and in which said step of embedding said strip in said frame is carried out by laminating said strip between two laminar elements of said frame to form an integral vented frame.

10. The method of claim 8, in which said cells are sealed under vacuum.

11. The method of claim 8, in which pressure is applied at least to the edges of the battery while heating, and in which said vacuum is established before said heat and pressure are applied.

12. A flat laminar battery comprising a contiguous stack of laminar cells electrically connected in series by conductive plastic intercell connectors and terminated by conductive plastic current collectors;

said battery further comprising thermoplastic frames of liquid impermeable, gas permeable material, said frames being formed with central openings to receive active components of said cells;

said frames being located between and separating said intercell connectors and said current collectors;

said frames and said current collectors being sealed together at their outer peripheries only to provide a liquid impervious enclosure for said cells; and

at least one elongated strip of paper extending along a region within said sealed outer periphery through said sealed outer periphery to at least one end exposed to the atmosphere, said strip being surrounded along its length by a liquid impermeable barrier.

13. A flat laminar battery comprising a contiguous stack of laminar cells terminated by conductive plastic current collectors;

said battery further comprising thermoplastic frames of liquid impermeable, gas permeable material, said frames being formed with central openings to receive active components of said cells;

said frames being located between and separating said current collectors;

said frames and said current collectors being sealed together at their outer peripheries only to provide a liquid impervious enclosure for said cells; and

at least one elongated strip of paper embedded in one of said frames surrounded along its length by liquid impermeable, gas permeable material, said strip extending along a region within said sealed outer periphery through said sealed outer periphery to at least one end exposed to the atmosphere.