Flow batteries having an electrode with differing hydrophilicity on opposing faces and methods for production and use thereof

Patent metadata

Field	Value
Publication number	US-2020152993-A1
Application number	US-202016743599-A
Country	US
Kind code	A1
Filing date	Jan 15, 2020
Priority date	Oct 18, 2016
Publication date	May 14, 2020
Grant date	—

Abstract

Electrochemical cells, such as those present within flow batteries, can include at least one electrode with one face being more hydrophilic than is the other. Such electrodes can lessen the incidence of parasitic reactions by directing convective electrolyte circulation toward a separator in the electrochemical cell. Flow batteries containing the electrochemical cells can include: a first half-cell containing a first electrode with a first face and a second face that are directionally opposite one another, a second half-cell containing a second electrode with a first face and a second face that are directionally opposite one another, and a separator disposed between the first half-cell and the second half-cell. The first face of both the first and second electrodes is disposed adjacent to the separator. The first face of at least one of the first electrode and the second electrode is more hydrophilic than is the second face.

First claim

What is claimed is the following:

1 . A method comprising
providing a conductive material configured as a sheet having a first face and a second face that are directionally opposite one another, the first face being more hydrophilic than the second face; and forming an electrochemical cell comprising:
a first half-cell containing a first electrode;
a second half-cell containing a second electrode; and
a separator disposed between the first half-cell and the second half-cell;

wherein at least one of the first electrode and the second electrode comprises the conductive material positioned such that the first face of the conductive material is disposed adjacent to the separator.

2 . The method of claim 1 , wherein the conductive material comprises a carbon cloth.

3 . The method of claim 2 , further comprising functionalizing the first face of the conductive material to a greater extent than the second face, thereby rendering the first face more hydrophilic than the second face.

4 . The method of claim 3 , wherein the conductive material is plasma functionalized upon the first face to a greater extent than upon the second face, thereby rendering the first face more hydrophilic than the second face.

5 . The method of claim 3 , wherein the conductive material is functionalized upon the first face to a greater extent than upon the second face with a plurality of hydrophilic molecules, thereby rendering the first face more hydrophilic than the second face.

6 . The method of claim 2 , further comprising functionalizing the second face of the conductive material to a greater extent than the first face with a plurality of hydrophobic molecules, thereby rendering the first face more hydrophilic than the second face.

7 . The method of claim 2 , wherein the conductive material comprises a first carbon cloth and a second carbon cloth that are layered together such that the first carbon cloth is adjacent to the separator, and the first carbon cloth is more hydrophilic than is the second carbon cloth.

8 . The method of claim 1 , wherein the electrochemical cell is located within a flow battery.

9 . The method of claim 1 , wherein a first bipolar plate contacts the first electrode opposite the separator and a second bipolar plate contacts the second electrode opposite the separator.

10 . The method of claim 9 , further comprising connecting a plurality of the electrochemical cells in series with one another in an electrochemical stack.

11 . A method comprising:
circulating a first electrolyte solution through a first half-cell and a second electrolyte solution through a second half-cell of an electrochemical cell of a flow battery, the electrochemical cell comprising: the first half-cell containing a first electrode with a first face and a second face that are directionally opposite one another; the second half-cell containing a second electrode with a first face and a second face that are directionally opposite one another; and a separator disposed between the first half-cell and the second half-cell; wherein the first faces of both the first and second electrodes are disposed adjacent to the separator, and the first face of at least one of the first electrode and the second electrode is more hydrophilic than is the second face of the respective electrode; and; wherein convective flow of at least one of the first electrolyte solution and the second electrolyte solution occurs preferentially in a hydrophilic region of the first electrode or the second electrode proximate the separator.

12 . The method of claim 11 , wherein a first bipolar plate contacts the second face of the first electrode and a second bipolar plate contacts the second face of the second electrode, and the first electrolyte solution and the second electrolyte solution are supplied through a plurality of flow channels within the first bipolar plate and the second bipolar plate, respectively.

13 . The method of claim 11 , wherein the first face of both the first and second electrodes is more hydrophilic than is the second face of the respective electrode.

Assignees

• Lockheed Martin Energy Llc

Inventors

• Loretz Jeremy
• Puranam Srivatsava Venkataranga
• Vanbenschoten Helen Elizabeth

Classifications

• H01M4/8642 Primary

  Gradient in composition · CPC title

• H01M4/96

  Carbon-based electrodes · CPC title

• H01M8/188

  by recharging of redox couples containing fluids; Redox flow type batteries · CPC title

• H01M4/8605

  Porous electrodes · CPC title

• H01M4/8657

  layered · CPC title