ZINC ELECTRODES FOR BATTERIES

• US 20140147757A1
• Filed: 03/15/2013
• Published: 05/29/2014
• Est. Priority Date: 11/28/2012
• Status: Active Grant

• Current Assignee: The Government Of The United States As Represented By The Secretary Of The Navy
• Original Assignee: United States Department Of Health And Human Services
• Inventors: Rolison, Debra R., Long, Jeffrey W., Parker, Joseph F.
• Granted Patent: US 10,008,711 B2
• Time in Patent Office: Days
• US Class Current: 429/406
• CPC Class Codes: H01M 12/085 Zinc-halogen cells or batteries
• CPC Class Codes: H01M 4/043 involving compressing or compaction
• CPC Class Codes: H01M 4/0471 involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
• CPC Class Codes: H01M 4/42 Alloys based on zinc
• CPC Class Codes: H01M 4/628 Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
• 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

Abstract

An article having a continuous network of zinc and a continuous network of void space interpenetrating the zinc network. The zinc network is a fused, monolithic structure. A method of: providing an emulsion having a zinc powder and a liquid phase; drying the emulsion to form a sponge; sintering the sponge to form a sintered sponge; heating the sintered sponge in an oxidizing atmosphere to form an oxidized sponge having zinc oxide on the surface of the oxidized sponge; and electrochemically reducing the zinc oxide to form a zinc metal sponge.

Claims

1. An article comprising;

a continuous network comprising zinc; and

a continuous network of void space interpenetrating the zinc network;

wherein the zinc network is a fused, monolithic structure.

2. The article of claim 1, wherein both the surface of the zinc network and the interior of the zinc network comprise zinc.

3. The article of claim 1, wherein the surface of the zinc network comprises one or more of zinc oxide and zinc oxide oxyhydroxides.

4. The article of claim 1, wherein the article is made by:

providing an emulsion comprising a zinc powder and a liquid phase;

drying the emulsion to form a sponge;

sintering the sponge to form a sintered sponge;

heating the sintered sponge in an oxidizing atmosphere to form an oxidized sponge comprising zinc oxide on the surface of the oxidized sponge; and

electrochemically reducing the zinc oxide to form a zinc metal sponge.

5. The article of claim 4, wherein the zinc powder or liquid phase comprises an additive that suppresses gas evolution and corrosion of the sponge.

6. The article of claim 5, wherein the additive comprises bismuth and indium.

7. An electrochemical cell comprising:

an anode current collector;

an anode comprising the article of claim 1 in electrical contact with the anode current collector;

an electrolyte filling the void space;

a cathode current collector;

a cathode in electrical contact with the anode current collector; and

a separator between the anode and the cathode.

8. The electrochemical cell of claim 7, wherein the electrochemical cell is a zinc-air battery.

9. A method comprising:

providing an emulsion comprising a zinc powder and a liquid phase;

drying the emulsion to form a sponge;

sintering the sponge to form a sintered sponge;

heating the sintered sponge in an oxidizing atmosphere to form an oxidized sponge comprising zinc oxide on the surface of the oxidized sponge; and

electrochemically reducing the zinc oxide to form a zinc metal sponge.

10. The method of claim 9, wherein the zinc powder or liquid phase comprises an additive that suppresses gas evolution and corrosion of the sponge.

11. The method of claim 10, wherein the additive comprises bismuth and indium.

12. The method of claim 9, wherein the liquid phase emulsion comprises water and decane.

13. The method of claim 9, wherein the emulsion comprises an emulsifier and an emulsion stabilizer.

14. The method of claim 13, wherein the emulsifier is sodium dodecyl sulfate and emulsion stabilizer is carboxymethylcellulose.

15. The method of claim 9, wherein the sintering is performed under argon at a peak temperature of 200-410°

C.

16. The method of claim 9, wherein the heating is performed in air at a peak temperature greater than 420°

C.

17. The method of claim 9, wherein the zinc oxide is reduced by applying a negative voltage to the oxidized sponge until the open-circuit potential vs. zinc is less than 5 mV.