Battery with electrochemical tester

• US 5,339,024 A
• Filed: 07/22/1992
• Issued: 08/16/1994
• Est. Priority Date: 09/24/1991
• Status: Expired due to Term

• Current Assignee: Gillette Company (The Procter & Gamble Company)
• Original Assignee: Duracell Incorporated (Berkshire Hathaway Incorporated)
• Inventors: Lin, LiFun, Chi, Ignacio, Wu, Louis L., Kuo, Han C.
• Primary Examiner(s): Wieder, Kenneth A.
• Assistant Examiner(s): BROWN, GLENN WARNER
• Application Number:
  US07/914,944
• Time in Patent Office: 755 Days
• Field of Search: 324/435, 324/426, 324/103 R, 324/104, 340/636, 320/48, 429/90, 429/91, 429/92, 429/93, 204/400, 204/407
• US Class Current: 324/435
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 16/00 Structural combinations of different types of electrochemical generators
• CPC Class Codes: H01M 6/5044 Cells or batteries structurally combined with cell condition indicating means
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y10S 320/21 State of charge of battery

Abstract

The present invention relates to an electrochemical cell and a related state of charge indicator comprising an electrochemically generated display. The state of charge indicator comprises two electrical contacts and an electrochemically generated display connected therebetween. The display comprises an electrochemical cell that may be permanently connected to a main cell in a parallel configuration via the contacts. The condition of the main cell may thus be continuously displayed on the indicator.

Claims

1. A condition indicator for an electrochemical power source, said indicator comprising an anode active layer, a cathode active layer and an electrolyte layer, said electrolyte layer contacting at least a portion of both said anode and cathode active layers, said condition indicator being geometrically designed to provide a predetermined selective discharge pattern whereby the discharge reaction begins at a first region of one of said anode and cathode active layers and continues therefrom towards remote regions thereof.

2. A condition indicator for an electrochemical power source, said indicator comprising an anode active layer, a cathode active layer and an electrolyte layer, said electrolyte layer contacting at least a portion of both said anode and cathode active layers, wherein at least a portion of one of said anode and cathode active layers being laterally spaced from the other.

3. The condition indicator of claim 2 wherein no portion of the anode active layer overlaps any portion of the cathode active layer.

4. The cell condition indicator of claim 2 wherein the indicator has a thickness of less than about 100 mils (2.5 mm) and the power source is an electrochemical cell.

5. The combination of an electrochemical cell and a cell condition indicator in contact with said electrochemical cell, said electrochemical cell comprising an outer surface, a negative terminal and a positive terminal and said indicator comprising a laminate comprising an anode layer, a cathode layer and electrolyte contacting at least a portion of both said cathode and anode layers, wherein the anode layer and cathode layer are laterally spaced apart so that no portion of the anode layer overlaps any portion of the cathode layer.

6. The combination of claim 5 wherein the condition indicator has a thickness between about 4 and 15 mils (0.1 and 0.4 mm).

7. The combination of claim 5 wherein the electrolyte comprises an electrolytic film having at least two opposing sides and said electrolytic film having a conductivity of at least 1×

10^-7 ohm^-1 cm^-1.

8. The combination of claim 7 wherein the same side of the electrolytic film contacts at least a portion of both said anode layer and said cathode layer.

9. The combination of claim 7 wherein the anode and cathode layers are on opposite sides of the electrolytic film.

10. The combination of claim 7 wherein the anode and cathode layers are electrically insulated from adjacent portions of said electrochemical cell outer surface.

11. The combination of claim 7 wherein the electrolytic film comprises a porous polymeric film retaining a liquid electrolyte solution within the pores of said polymeric film.

12. The combination of claim 11 wherein the liquid electrolyte solution comprises an ionic salt dissolved therein, said ionic salt selected from the group consisting of LiCF₃ SO₃, LiClO₄, Zn(CF₃ SO₃)₂ and Zn(ClO₄)₂, LiN(CF₃ SO₂)₂ and combinations thereof;

wherein said polymeric film is selected from the group consisting of polyvinylidene fluoride and polyacrylonitrile;

wherein the electrolyte solution comprises an organic solvent selected from the group consisting of ethylene carbonate and propylene carbonate and mixtures thereof; and

wherein the electrolytic film has a thickness between about 0.05 and 0.25 mm.

13. The combination of claim 5 wherein the cathode layer comprises a cathode active material which produces an open circuit voltage (OCV) for the condition indicator, which open circuit voltage is similar to the open circuit voltage of said electrochemical cell.

14. The combination of claim 5 wherein the anode layer is electrically connected to said negative terminal and the cathode layer is electrically connected to said positive terminal.

15. The combination of claim 14 wherein the condition indicator further comprises a color or indicia layer which is revealed when one of said cathode and anode active layers is electrochemically discharged.

16. The combination of claim 15 wherein said condition indicator forms part of a label for the electrochemical cell.

17. The combination of an electrochemical cell and a cell condition indicator in contact with said electrochemical cell, said electrochemical cell comprising an outer surface, a negative terminal and a positive terminal and said indicator comprising a laminate comprising an anode layer, a cathode layer and electrolyte contacting at least a portion of both said cathode and anode layers;

wherein the anode layer and cathode layer are laterally spaced apart so that no portion of the anode layer overlaps any portion of the cathode layer;

said indicator further comprising a color or indicia layer which is revealed when one of said cathode and anode active layers is electrochemically discharged;

wherein the anode layer comprises zinc; and

wherein the cathode layer comprises a mixture of a cathode active material and about 10 percent by weight of a conducting agent, the cathode active material selected from the group consisting of CoO₂, NiO₂ and lambda MnO₂, and said conducting agent selected from the group consisting of carbon black and graphite; and

wherein the electrolyte comprises an electrolytic film having a conductivity of at least 1×

10^-7 ohm^-1 cm^-1 and a thickness of between 0.05 and 0.25 mm, said electrolytic film comprising a porous polymeric film retaining a liquid electrolyte solution within the pores of said polymeric film, said polymeric film selected from the group consisting of polyvinylidene fluoride and polyacrylonitrile, the liquid electrolyte solution comprising an ionic salt dissolved in an organic solvent, said ionic salt selected from the group consisting of LiCF₃ SO₃, LiClO₄, Zn(CF₃ SO₃)₂ and Zn(ClO₄)₂, LiN(CF₃ SO₂)₂ and combinations thereof and the organic solvent selected from the group consisting of ethylene carbonate and propylene carbonate and mixtures thereof.