Dish shaped and pressure equalizing electrodes for electrochemical batteries

• US 8,632,901 B2
• Filed: 10/27/2008
• Issued: 01/21/2014
• Est. Priority Date: 10/26/2007
• Status: Expired due to Fees

• Current Assignee: G4 Synergetics, Inc.
• Original Assignee: G4 Synergetics, Inc.
• Inventors: West, Jon Kenneth, Higgins, Martin Patrick, Regalado, Julius, George, Anthony
• Primary Examiner(s): Gilliam, Barbara
• Assistant Examiner(s): MARTIN, ANGELA J
• Application Number:
  US12/258,854
• Publication Number:
  US 20090142655A1
• Time in Patent Office: 1,912 Days
• Field of Search: None
• US Class Current: 429/53
• CPC Class Codes: H01M 10/0413 Large-sized flat cells or batteries for motive or stationary systems with plate-like electrodes
• CPC Class Codes: H01M 10/0418 with bipolar electrodes
• CPC Class Codes: H01M 10/044 with bipolar electrodes
• CPC Class Codes: H01M 10/282 with bipolar electrodes
• CPC Class Codes: H01M 10/345 Gastight metal hydride accumulators
• CPC Class Codes: H01M 10/4235 Safety or regulating additives or arrangements in electrodes, separators or electrolyte H01M10/4242 takes precedence
• CPC Class Codes: H01M 50/317 Re-sealable arrangements
• CPC Class Codes: H01M 50/342 Non-re-sealable arrangements
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/49108 Electric battery cell making

Abstract

A stacked battery has at least two cell segments arranged in a stack. Each cell segment may have a first electrode unit having a first active material electrode, a second electrode unit having a second active material electrode, and an electrolyte layer between the active material electrodes. One or more gaskets may be included in each cell segment to seal the electrolyte within the cell segment. The electrode units may be “dish shaped” and may contain a pressure equalization valve to reduce electrode unit deflection and improve pressure equalization between cell segments. The pressure equalization valve may allow a gas to diffuse through adjacent cell segments and may substantially prevent electrolyte from diffusing through.

Claims

1. A bi-polar battery comprising:

a positive mono-polar electrode unit;

a negative mono-polar electrode unit;

at least one bi-polar electrode unit stacked between said positive electrode unit and said negative electrode unit, wherein the at least one bi-polar electrode unit comprises a pressure equalization valve disposed in a substrate of the bi-polar electrode unit, wherein the pressure equalization valve is formed of a sealant and a graphitic carbon fiber material;

an electrolyte layer provided between each pair of adjacent electrode units; and

a gasket positioned about each of said electrolyte layers, wherein each of said electrolyte layers is sealed by its respective gasket and its respective pair of adjacent electrode units.

2. The battery of claim 1, wherein the pressure equalization valve is resistant to chemical corrosion.

3. The battery of claim 1, wherein the pressure equalization valve has at least one of nanometer sized perforations and micrometer sized perforations.

4. The battery of claim 3, wherein an electrolyte is prevented from passing between adjacent electrolyte layers by the pressure equalization valve.

5. The battery of claim 3, wherein a gas is permitted to pass between adjacent electrolyte layers by the perforations in the pressure equalization valve.

6. The battery of claim 1, wherein the graphitic carbon fiber material comprises

a graphitic carbon fiber bundle.

7. The battery of claim 6, wherein gas molecules are chemically transferred between adjacent electrolyte layers along the graphitic fiber bundle.

8. The battery of claim 6, wherein diffusion forces allow hydrogen molecules from an over pressurized electrolyte layer to travel along the surface of the graphitic fiber bundle.

9. The battery of claim 6, wherein an electrolyte is prevented from passing between adjacent electrolyte layers by the pressure equalization valve.

10. The battery of claim 6, wherein the graphitic carbon fiber bundle comprises about 1,000 fibrils cured within the sealant.

11. The battery of claim 1, wherein the substrate comprises a curved shape that prevents electrolyte from pooling around the pressure equalization valve.

12. An energy storage device comprising:

a substrate having a pressure equalization valve therein, wherein the pressure equalization valve allows gases to travel through the otherwise impervious substrate but prevents an electrolyte from traveling therethrough, and wherein the pressure equalization valve is formed of a sealant and a graphitic carbon fiber material.

13. The energy storage device of claim 12, wherein the graphitic carbon fiber material comprises a graphitic carbon fiber bundle.

14. The energy storage device of claim 13, wherein the graphitic carbon fiber bundle comprises about 1,000 fibrils cured within the sealant.

15. The energy storage device of claim 12, further comprising a positive active material electrode layer on a first side of the substrate and a negative active material electrode layer on a second side of the substrate opposite the first side.

16. The energy storage device of claim 15, wherein the pressure equalization valve is disposed in the substrate and surrounded on both sides of the substrate by the respective positive and negative active material electrode layers.

17. The energy storage device of claim 12, wherein the substrate has a curved shape that prevents electrolyte from pooling around the pressure equalization valve.