Flat battery and manufacture thereof

• US 3,988,168 A
• Filed: 10/20/1975
• Issued: 10/26/1976
• Est. Priority Date: 06/10/1974
• Status: Expired due to Term

• Current Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Original Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Inventors: Bruneau, Louis O.
• Primary Examiner(s): Mack, John H.
• Assistant Examiner(s): Lefevour, C. F.
• Application Number:
  US05/624,053
• Time in Patent Office: 372 Days
• Field of Search: 136/111, 136/175, 136/6 B, 136/6 S, 136/133
• US Class Current: 429/129
• CPC Class Codes: H01M 6/48 with bipolar electrodes

Abstract

A flat battery structure and method of fabricating it which is characterized by a distinctive integration of the arrangement and dimensions of discrete components of the battery pile structure. Through the select dimensioning and positioning of discrete components of the battery, an especially efficient high speed production process for batteries of improved operational reliability is realized.

Claims

1. In a flat primary battery structure comprising sheet type separators between electrochemically active battery sheet elements comprising anode materials, cathode materials and electrolyte combined with sheet type electrically conductive intercell connectors and electrically conductive oppositely disposed sheet type current collector elements combined to form a series connected multicell structure by seals entirely surrounding said electrochemically active elements and formed between the peripheries of the sheet type, electrically conductive, intercell connectors and contiguous portions of the sheet type separators;

the improvement wherein the overall peripheral dimensions of the separators exceed the overall peripheral dimensions of the connectors and active elements and the peripheral dimensions of the intercell connectors exceed the peripheral dimensions of the electrochemically active elements so that the peripheral portions of the separators extend beyond all the peripheral portions of the electrochemically active elements and intercell connectors sealed thereto.

2. The battery of claim 1 further including an electrically insulating sheet material attached extremely against one surface of said sheet collector element and at least coextensive therewith.

3. The battery of claim 2 wherein said electrically insulating sheet material is configured having an access opening therein for exposing a select portion of the said surface of said one said sheet collector element to provide a terminal for said battery structure.

5. The battery of claim 2 wherein:

said electrically insulating sheet material is configured having an access opening therein for exposing a select portion of the said surface of said one said sheet collector element to provide a terminal for said battery structure; and

said sheet collector element opposite said attached collector element is configured such that a portion thereof is foldable against said electrically insulating sheet material so as to provide another terminal defining surface of said battery adjacent said last mentioned terminal.

6. The battery of claim 2 wherein said electrically insulating sheet material is polyethylene terephthalate.

7. The battery of claim 2 in which said electrically insulating sheet material is opaque to actinic radiation incident thereon.

8. The battery of claim 2 wherein said electrically insulating sheet material is configured having a size at least coextensive with said sheet type separator elements.

9. The battery of claim 5 including packaging means encapsulating said battery structure and including openings for selectively exposing said terminal surfaces.

4. The battery of claim 4 wherein a said sheet collector element opposite said attached collector element is configured such that a portion thereof is foldable against said electrically insulating sheet material so as to provide a terminal defining surface of said battery.

10. In a flat battery comprising the combination of:

means defining a series connected, multicell structure including first and second outwardly disposed electrodes, electrolyte layers and separator means comprising sheet type separators having sheet type electrically conductive intercell connectors whose peripheries are sealed to contiguous portions of said separators to form seals entirely surrounding said electrolyte layers;

first and second flat sheet collector means electrically coupled, respectively, with the first and second outwardly disposed electrodes;

the improvement wherein the overall peripheral dimensions of the separators exceed the overall peripheral dimensions of the first and second electrodes and of the conductive connectors so that the peripheral portions of the separators extend beyond all the peripheral portions of the electrodes and of the conductive connectors sealed thereto.

11. A battery of claim 10 further including an electrically insulative sheet mounted adjacent a select one of said first and second flat sheet collector means and having an access opening formed therein to expose a portion of the surface of said select collector means so as to define a terminal of said battery.

12. The battery of claim 10 in which said electrically insulative sheet material is configured having dimensions at least coextensive with said select one of said flat sheet collector means.

13. The battery of claim 10 wherein one said flat sheet collector means is configured such that a portion thereof is foldable against said electrically insulative sheet so as to provide a terminal defining surface of said battery.

14. The battery of claim 10 in which said electrically insulative sheet is opaque to actinic radiation incident thereon.

15. The battery of claim 10 in which said electrically insulative sheet is polyethylene terephthalate.

16. The battery of claim 13 including packaging means for encapsulating said battery structure and including access openings for selectively exposing said terminal defining surfaces.

17. In a method for constructing flat battery units comprising the steps of assembling the elements and components of the battery by fixedly placing in selectively spaced alignment a predetermined sequence of electrolyte, anode and cathode materials in combination with discrete sheet type separators and discrete electrically active battery sheet elements including current collectors and sheet type, electrically conductive, intercell connectors to form a discrete series connected, multicell structure assembly by sealing the peripheries of the sheet type, electrically conductive, intercell connectors to contiguous portions of the sheet type separators to form continuous seals entirely surrounding the anode, cathode and electrolyte materials;

the improvement wherein the overall peripheral dimensions of the separators are formed to exceed the overall peripheral dimensions of the connectors sealed thereto, and wherein said connectors are placed within the boundaries of said separators so that said separators overlap said connectors on all sides.

18. The method of claim 17 wherein said sequence of electrolyte, anode and cathode materials, separators and sheet elements are fixedly placed in selectively spaced alignment on a continuous carrier sheet of electrically insulative material.

19. The method of claim 18 in which said continuous carrier sheet is provided having a widthwise dimension substantially corresponding with the width of a said flat battery unit.

20. The method of claim 18 including the step of providing access openings within said continuous carrier sheet to expose the surface of a said current collector thereby defining a terminal surface for each said constructed discrete flat battery units.

21. The method of claim 18 wherein the said placement of said flat cell assemblies is commenced with the step of fixedly positioning a first said current collector upon said continuous carrier, said current collector having a widthwise dimension less than the width of said carrier sheet.

22. The method of claim 20 wherein said access openings are provided at a predetermined repetitive spacing along said carrier sheet.

23. The method for constructing flat battery units of claim 21 including the step of providing access openings within said continuous carrier sheet to expose the surface of a said current collector thereby defining a terminal surface for each said constructed discrete flat battery units.

24. The method of claim 23 wherein the said placement of said flat cell assemblies in concluded with the step of fixedly positioning a second said current collector having a widthwise dimension greater than the width of said carrier sheet and extending beyond a width defining edge thereof.

25. The method of claim 24 wherein the placement of said flat cell assemblies includes the step of folding the portion of said second current collector extending beyond said carrier sheet over and in juxtaposition against said carrier sheet to define a terminal surface of said flat battery unit.

26. The method of claim 25 including the step of packaging said discrete flat battery units in a manner exposing relatively spaced and dimensional portions of said current collectors.

32. The method of claim 25 wherein said continuous carrier sheet is provided having a widthwise dimension corresponding with the width of one said battery.

27. In a method for constructing flat multicell batteries, the steps of:

providing a continuous carrier sheet of electrically insulative material;

fixedly positioning discrete first current collector assemblies in selectively spaced relationship upon said continuous carrier sheet;

forming a predetermined number of cells separated by sheet type electrically conductive intercell connectors upon each said collector assembly, each cell including cathode and anode electrodes between which there is disposed electrolyte and a sheet type separator, the electrodes and electrolyte lying within the boundaries of said intercell connectors and said first current collector assembly, and the separator extending beyond the boundaries of said intercell connectors and said first current collector assembly on all sides, by intersealing the peripheries of the sheet type, electrically conductive intercell connectors and said first current collector assembly to contiguous portions of the sheet type separator means, thereby forming continuous seals entirely surrounding the electrodes and electrolyte of all but the outermost cell;

positioning discrete second collector assemblies over and in electrical association with the outermost of said cells to form a multicell unit, and sealing said second collector assembly to the outermost separator to complete a continuous seal about the electrodes and electrolyte of said outermost cell, said second collector assemblies having a width selectively extending beyond the edge of said continuous carrier sheet;

folding said width of said second collector assembly extending beyond said carrier sheet about the edge thereof to a position juxtaposed against a surface thereof; and

sealing the periphery of each said multicell unit.

28. The method of claim 27 in which said continuous carrier sheet is provided having a widthwise dimension substantially corresponding with the width of a said flat battery unit.

29. The method of claim 27 including the step of providing access openings within said continuous carrier sheet to expose the surface of a said current collector thereby defining a terminal surface for each said constructed discrete flat battery units.

30. The method of claim 27 including the step of:

cutting said continuous carrier sheet between said multicell units.

31. The method of claim 27 including the steps of:

cutting said continuous carrier sheet between said multicell units; and

packaging said multicell units in a mannner exposing selectively spaced and dimensioned portions of said current collector.