Anaerobic Aluminum-Water Electrochemical Cell

Patent metadata

Field	Value
Publication number	US-2019020085-A1
Application number	US-201816057117-A
Country	US
Kind code	A1
Filing date	Aug 7, 2018
Priority date	Dec 4, 2012
Publication date	Jan 17, 2019
Grant date	—

Abstract

An anaerobic aluminum-water electrochemical cell that includes: a plurality of electrode stacks, each electrode stack featuring an aluminum or aluminum alloy anode, and at least one cathode configured to be electrically coupled to the anode; one or more physical separators between each electrode stack adjacent to the cathode; a housing configured to hold the electrode stacks, an electrolyte, and the physical separators; a water injection port, in the housing, configured to introduce water into the housing. The electrochemical cell also includes an amount of hydroxide base sufficient to form an electrolyte having a hydroxide base concentration of at least 0.05 M to at most 3 M when water is introduced between the anode and at least one cathode of the electrochemical cell. The aluminum or aluminum alloy of the anode is substantially free of titanium and boron.

First claim

1 . An anaerobic aluminum-water electrochemical cell comprising:
a plurality of electrode stacks, each electrode stack comprising an aluminum or aluminum alloy anode, and at least one cathode configured to be electrically coupled to the anode; one or more physical separators between each electrode stack adjacent to the cathode; a housing configured to hold the electrode stacks, an electrolyte, and the physical separators; a water injection port, in the housing, configured to introduce water into the housing, and an amount of hydroxide base sufficient to form an electrolyte having a hydroxide base concentration of at least 0.05 M to at most 3 M when water is introduced between the anode and at least one cathode of the electrochemical cell, wherein the aluminum or aluminum alloy of the anode is substantially free of titanium and boron.

2 . The electrochemical cell according to claim 1 , wherein the amount of hydroxide base is sufficient to form an electrolyte having a hydroxide base concentration of at least 0.1 M to at most 2.5 M.

3 . The electrochemical cell according to claim 1 , wherein the amount of hydroxide base is sufficient to form an electrolyte having a hydroxide base concentration of at least 0.25 M to at most 2 M.

4 . The electrochemical cell according to claim 1 , wherein the aluminum of the anode has a purity of at least 99.95 wt %.

5 . The electrochemical cell according to claim 1 , wherein the aluminum of the anode has a purity of at least 99.99 wt %.

6 . The electrochemical cell according to claim 1 , wherein the cathode has a surface having an electrochemical roughness factor of at least 5 .

7 . The electrochemical cell according to claim 1 , the cathode being in the form of a solid plate.

8 . The electrochemical cell according to claim 1 , wherein the one or more physical separators are formed from a mesh material having openings of about 100 μm or larger.

9 . An aluminum-water electrochemical system comprising:
an aluminum-water electrochemical cell according to claim 1 ; a waste separation system in fluid communication with the housing and configured to receive electrolyte and aluminum hydroxide waste from the aluminum-water electrochemical cell and to separate the aluminum hydroxide waste from the electrolyte; and a fuel injector, in fluid communication with the waste separation system and the water injection port, configured to receive the electrolyte from the waste separation system and to provide the electrolyte to the water injection port.

10 . The electrochemical system according to claim 9 , wherein the fuel injector is further configured to receive water from a water supply.

11 . The electrochemical system according to claim 9 , wherein each electrode stack includes two cathodes on either side of the anode.

12 . The electrochemical system according to claim 9 , further comprising an aqueous electrolyte.

13 . The electrochemical system according to claim 12 , wherein the electrolyte includes water and sodium chloride.

14 . The electrochemical system according to claim 9 , wherein the water injection port is configured to introduce the water into the housing so that the water flows through the physical separators.

15 . A method for generating an electrical current using an electrochemical cell comprising: a plurality of electrode stacks, each electrode stack comprising an aluminum or aluminum alloy anode, and at least one cathode configured to be electrically coupled to the anode; one or more physical separators between each electrode stack adjacent to the cathode; a housing configured to hold the electrode stacks, the electrolyte, and the physical separators; and a water injection port, in the housing, configured to introduce water into the housing, wherein: the electrolyte has a hydroxide base concentration of at least 0.05 M to at most 3 M, and the aluminum or aluminum alloy of the anode is substantially free of titanium and boron, the method comprising:
introducing water between an anode and at least one cathode of the electrochemical cell, to form the electrolyte; anaerobically oxidizing aluminum or an aluminum alloy; and electrochemically reducing water at the at least one cathode.

16 . The method according to claim 15 , wherein the electrolyte has a hydroxide base concentration of at least 0.1 M to 2.5 M.

17 . The method according to claim 15 , wherein the electrolyte has a hydroxide base concentration of at least 0.25 M to 2 M.

18 . The method according to claim 15 wherein the cathode has a surface having an electrochemical roughness factor of at least 5.

19 . The method according to claim 15 , wherein the aluminum of the anode has a purity of at least 99.95 wt %.

20 . The method according to claim 15 , wherein the aluminum of the anode has a purity of at least 99.99 wt %.

Assignees

• Massachusetts Inst Technology

Inventors

• Mckay Ian Salmon
• Macdonald Ruaridh R
• Milnes Thomas B

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

• H01M8/04283

  Supply means of electrolyte to or in matrix-fuel cells · CPC title

• H01M8/04828

  Humidity; Water content · CPC title

• H01M8/18

  Regenerative fuel cells, e.g. redox flow batteries or secondary fuel cells · CPC title

• H01M8/20

  Indirect fuel cells, e.g. fuel cells with redox couple being irreversible (H01M8/18 takes precedence) · CPC title