Anaerobic Aluminum-Water Electrochemical Cell

Patent metadata

Field	Value
Publication number	US-2019036185-A1
Application number	US-201816057285-A
Country	US
Kind code	A1
Filing date	Aug 7, 2018
Priority date	Dec 4, 2012
Publication date	Jan 31, 2019
Grant date	—

Abstract

An anaerobic aluminum-water electrochemical cell is provided. The electrochemical cell includes: 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 and having a surface characterized by an electrochemical roughness factor of at least 5 and a mean pore diameter of at least 50 μm; 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; and a water injection port, in the housing, configured to introduce water into the housing.

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 and having a surface characterized by an electrochemical roughness factor of at least 5 and a mean pore diameter of at most 50 μm; 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; and a water injection port, in the housing, configured to introduce water into the housing.

2 . The electrochemical cell according to claim 1 , the cathode surface electrochemical roughness factor being at least 10.

3 . The electrochemical cell according to claim 1 , the cathode surface electrochemical roughness factor being at least 15.

4 . The electrochemical cell according to claim 1 , the cathode surface electrochemical roughness factor being at least 20.

5 . The electrochemical cell according to claim 1 , the mean pore diameter being at most 100 μm.

6 . The electrochemical cell according to claim 1 , further comprising 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 an electrochemical cell.

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

8 . The electrochemical cell according to claim 1 , wherein the aluminum or aluminum alloy of the anode is substantially free of titanium and boron.

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 electrolyte, the electrolyte comprising at least one hydroxide base at a concentration of at least 0.25 M to at most 2 M.

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 and having a surface characterized by an electrochemical roughness factor of at least 5 and a mean pore diameter of at most 50 μm; 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; and a water injection port, in the housing, configured to introduce water into the housing, the method comprising:
introducing water between the 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 , the cathode surface electrochemical roughness factor being at least 10.

17 . The method according to claim 15 , the cathode surface electrochemical roughness factor being at least 15.

18 . The method according to claim 15 , wherein the water includes sodium chloride.

19 . The method according to claim 15 , the electrolyte having a hydroxide base concentration of at least 0.05 M to at most 3 M.

20 . The method according to claim 15 , the electrolyte having a hydroxide base concentration of at least 0.1 M to at most 2.5 M.

Assignees

• Massachusetts Inst Technology

Inventors

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

Classifications

• H01M6/34

  Immersion cells, e.g. sea-water cells · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M12/02

  Details (of electrodes H01M4/00; of non-active parts H01M50/00) · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M2300/0014

  Alkaline electrolytes · CPC title