Zinc electrodes for batteries

Patent metadata

Field	Value
Publication number	US-10720635-B2
Application number	US-201715797181-A
Country	US
Kind code	B2
Filing date	Oct 30, 2017
Priority date	Nov 28, 2012
Publication date	Jul 21, 2020
Grant date	Jul 21, 2020

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; annealing and/or sintering the sponge to form an annealed and/or sintered sponge; heating the annealed and/or 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.

First claim

What is claimed is:

1. An article comprising;
a continuous network comprising metallic zinc; and
a continuous network of void space interpenetrating the zinc network;
wherein the zinc network comprises a fused, monolithic structure;
wherein the article comprises metallic zinc bridges connecting metallic zinc particle cores; and
wherein the article is made by:
providing a mixture comprising a metallic zinc powder and a liquid phase emulsion;
wherein the particle size distribution of all of the metallic zinc powder used to make the article has two maxima;

drying the mixture to form a sponge;
sintering the sponge in an inert atmosphere or under vacuum at a temperature below the melting point of zinc to form a sintered sponge having a metallic zinc surface; and
heating the sintered sponge in an oxidizing atmosphere at a temperature above the melting point of zinc to form a zinc oxide shell on the surface of the sintered sponge.

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 zinc network is substantially uniformly conductive.

5. The article of claim 1 , wherein the inert atmosphere is argon or nitrogen.

6. The article of claim 1 , wherein the article is further made by:
reducing the zinc oxide.

7. The article of claim 1 , wherein the void space comprises 10-75 micron-sized pores.

8. The article of claim 1 ;
wherein one of the two maxima is in a range of 2-20 microns; and
wherein the other of the two maxima is in a range of 20-75 microns.

9. 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.

10. The electrochemical cell of claim 9 , wherein the electrochemical cell is a zinc-air battery.

11. The electrochemical cell of claim 9 , wherein the anode can be oxidized and reduced for at least 45 cycles without the formation of zinc dendrites.

12. A method comprising:
providing a mixture comprising a metallic zinc powder and a liquid phase emulsion;
wherein the particle size distribution of all of the metallic zinc powder used to make the article has two maxima;

drying the mixture to form a sponge;
sintering the sponge at a temperature below the melting point of zinc to form a sintered sponge; and
heating the sintered sponge in an oxidizing atmosphere at a temperature above the melting point of zinc to form a zinc oxide shell on the surface of the sintered sponge.

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

14. The method of claim 2 , wherein the emulsion comprises an emulsifier and an emulsion stabilizer.

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

16. The method of claim 12 ;
wherein one of the two maxima is in a range of 2-20 microns; and
wherein the other of the two maxima is in a range of 20-75 microns.

17. The method of claim 12 , wherein the sintering is performed under argon at a peak temperature of 200-410° C.

18. The method of claim 12 , wherein the heating is performed in air at a peak temperature greater than 420° C.

19. The method of claim 12 ,
wherein the sintering is performed in an inert atmosphere or under vacuum; and
wherein the sintered sponge has a metallic zinc surface.

20. The method of claim 19 , the inert atmosphere is argon or nitrogen.

21. The method of claim 12 , further comprising:
reducing the zinc oxide.

22. The method of claim 21 , 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.

23. An electrochemical cell comprising:
an anode current collector;
an anode in electrical contact with the anode current collector;
wherein the anode is made by a method comprising:
providing a mixture comprising a metallic zinc powder and a liquid phase emulsion;
drying the mixture to form a sponge;
annealing and/or sintering the sponge in an inert atmosphere or under vacuum at a temperature below the melting point of zinc to form an annealed sponge having a metallic zinc surface; and
heating the annealed sponge in an oxidizing atmosphere at a temperature above the melting point of zinc to form an oxidized sponge comprising a zinc oxide shell on the surface of the oxidized sponge;
wherein the anode comprises:
a continuous network comprising metallic zinc;
a continuous network of void space interpenetrating the zinc network; and
metallic zinc bridges connecting metallic zinc particle cores;

an electrolyte filling the void space;
a cathode current collector;
a cathode comprising carbon; and
a separator between the anode and the cathode.

24. An article made by method comprising:
providing a mixture comprising a zinc powder and a liquid phase emulsion;
drying the emulsion to form a sponge;
sintering the sponge in an inert atmosphere 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
heating the oxidized sponge in an inert atmosphere at above the melting, point of the zinc.

Assignees

• Us Gov Sec Navy

Inventors

• Rolison Debra R
• Parker Joseph F
• Long Jeffrey W
• Ko Jesse S

Classifications

• H01M12/08 Primary

  composed of a half-cell of a fuel-cell type and a half-cell of the secondary-cell type · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M10/054

  Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium · CPC title

• H01M4/38

  of elements or alloys · CPC title

• H01M2220/30

  Batteries in portable systems, e.g. mobile phone, laptop · CPC title