Rechargeable ZnMn flat plate electrode cell

• US 8,968,424 B2
• Filed: 08/20/2013
• Issued: 03/03/2015
• Est. Priority Date: 09/26/2008
• Status: Active Grant

• Current Assignee: Encell Technology, Inc
• Original Assignee: Encell Technology, Inc
• Inventors: Ogg, Randy Gene
• Primary Examiner(s): Cano, Milton I
• Assistant Examiner(s): VO, JIMMY
• Application Number:
  US13/971,580
• Publication Number:
  US 20130333205A1
• Time in Patent Office: 560 Days
• Field of Search: 429/235, 429/162, 429/233, 429/241, 296/235
• US Class Current: 29/623.5
• CPC Class Codes: H01M 10/02 Details of electrodes H01M4/00; of non-active parts H01M50/00
• 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 10/0585 of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
• CPC Class Codes: H01M 10/281 Large cells or batteries with stacks of plate-like electrodes
• CPC Class Codes: H01M 4/0402 Methods of deposition of the material
• CPC Class Codes: H01M 4/244 Zinc electrodes
• CPC Class Codes: H01M 4/42 Alloys based on zinc
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: H01M 4/50 of manganese
• CPC Class Codes: H01M 4/502 for non-aqueous cells H01M4/505 takes precedence
• CPC Class Codes: H01M 4/808 Foamed, spongy materials
• CPC Class Codes: H01M 6/02 Details of electrodes H01M4/00; of non-active parts H01M50/00
• 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 29/49115 including coating or impregnating

Abstract

Provided is a flat plate electrode cell, comprises positive electrode plates and negative electrode plates. The positive electrode plates each comprise manganese and compressed metal foam. The negative electrode plates each comprise zinc and compressed metal foam. Both the positive and negative electrodes can have alignment tabs, wherein the flat plate electrode cell can further comprise electrical terminals tanned from the aligned tabs. The rechargeable flat plate electrode cell of the present disclosure, formed from compressed metal foam, provides both low resistance and high rate performance to the electrodes and the cell. Examples of improvements over round bobbin and flat plate cells are current density, memory effect, shelf life, charge retention, and voltage level of discharge curve. In particular, the rechargeable flat plate electrode cell of the present disclosure provides longer cycle life with reduced capacity fade as compared with known round bobbin and flat plate cells.

Claims

1. A process of preparing a flat plate electrode cell comprising the steps of:

a) Coating a metal foam mesh substrate on and throughout the foam mesh with an anode active paste;

b) Coating a metal foam mesh substrate on and throughout the foam mesh with a cathode active paste;

c) Compressing the metal foam substrate with the anode active paste comprises zinc between 42 and 45% of the original thickness to prepare an anode electrode;

d) Compressing the metal foam substrate with the cathode active paste comprises manganese between 42 and 45% of the original thickness to prepare a cathode electrode; and

e) Combining the anode and cathode electrode to form the cell.

2. The process of claim 1, wherein the metal foam substrate used with the anode paste has a volume of void spacing in the range of from 75-95%.

3. The process of claim 1, wherein the metal foam substrate used with cathode paste has a volume of void spacing in the range of from 75-95%.

4. The process of claim 1, wherein the compression of the metal foam substrate to prepare a cathode results in a coated size thickness for the cathode in the range of from 0.0200 to 0.0300 inches.

5. The process of claim 1, wherein the compression of the metal foam substrate to prepare an anode results in a coated size thickness for the anode in the range from 0.0200 to 0.0300 inches.

6. The process of claim 1, wherein more than one anode electrode and more than one cathode electrode are prepared, and the anodes and cathodes are stacked in an alternating cathode and anode pattern.

7. The process of claim 6, wherein the cathode electrodes are connected together and the anode electrodes are connected together.

8. The process of claim 1, wherein the metal foam is a nickel foam.

9. The process of claim 1, wherein the metal foam is a copper plated nickel foam.

10. The process of claim 1, wherein the anode paste comprises 75-98% zinc active material.

11. The process of claim 10, wherein the zinc active material comprises lead-free zinc or zinc alloy.

12. The process of claim 10, where the anode paste further comprises from 0.01-1.0 wt % polymeric binder.

13. The process of claim 1, wherein the cathode paste comprises from about 70-90 wt % manganese dioxide.

14. The process of claim 1, wherein the cathode paste comprises from about 2-15% of graphite and/or carbon black.

15. The process of claim 13, wherein the cathode paste further comprises from 3-10 wt % polymeric binder.

16. The process of claim 1, wherein the anode paste and/or the cathode paste contain carboxymethyl cellulose (CMC).

17. The process of claim 16, where the amount of CMC in the paste is about 2 wt %.