Methods and system for manufacturing a redfox flow battery system by roll-to-roll processing

Patent metadata

Field	Value
Publication number	US-2020052318-A1
Application number	US-201916536216-A
Country	US
Kind code	A1
Filing date	Aug 8, 2019
Priority date	Aug 10, 2018
Publication date	Feb 13, 2020
Grant date	—

Abstract

Methods and systems are provided for manufacturing a bipolar plate for a redox flow battery. In one example, the bipolar plate is fabricated by a roll-to-roll process. The bipolar plate includes a non-conductive substrate that is coupled to a negative electrode on a first surface and coupled to a positive electrode on a second surface, the first surface opposite of the second surface.

First claim

1 . A method for fabricating a bipolar plate, comprising;
arranging a flexible substrate between a first roller and a second roller; moving the flexible substrate in a direction from the first roller towards the second roller; coupling a top surface of the flexible substrate with a first conductive material as the flexible substrate is moving; coupling a bottom surface of the flexible substrate with a second material as the flexible substrate is moving; bonding the first conductive material and the second conductive material to the flexible layer and forming the bipolar plate, the flexible substrate sandwiched between the first conductive material and the second conductive material, as the flexible substrate is moving from the first roller to the second roller; and collecting the bipolar plate onto the second roller.

2 . The method of claim 1 , wherein coupling the first conductive material to the flexible substrate includes applying a layer of the first conductive material to the top surface of the non-conductive substrate by one of spin-coating, doctor-blading, or screen printing.

3 . The method of claim 1 , wherein coupling the first conductive material to the flexible substrate includes unreeling a roll of the first conductive material onto the top surface of the flexible substrate.

4 . The method of claim 1 , wherein coupling the second conductive material to the flexible substrate includes unreeling a roll of the second conductive material onto the bottom surface of the flexible substrate.

5 . The method of claim 1 , wherein bonding the first and second conductive materials to the flexible substrate includes heating and pressing the first and second conductive materials against the top and bottom surfaces, respectively, of the flexible substrate.

6 . The method of claim 1 , wherein bonding the bipolar plate includes sewing the bipolar plate with a thread formed from a conductive material.

7 . The method of claim 6 , further comprising inserting stitches of the thread through an entire thickness of each of the first conductive material and the flexible substrate, and through a portion of a thickness of the second conductive material, from a top face of the bipolar plate towards a bottom face of the bipolar plate.

8 . A redox flow battery system, comprising;
a battery cell including:
a bipolar plate assembly including an fluid-impermeable layer sandwiched between a negative electrode and a positive electrode;
a negative electrolyte in contact with the negative electrode; and
a positive electrolyte in contact with the positive electrode.

9 . The redox flow battery system of claim 8 , further comprising a membrane separator arranged between the negative electrode and a positive electrode of an adjacent battery cell, on an opposite side of the negative electrode from the bipolar plate.

10 . The redox flow battery system of claim 8 , wherein the fluid-impermeable layer is formed from carbon fiber imbedded with resin and separates the negative electrolyte from the positive electrolyte within the battery cell.

11 . The redox flow battery system of claim 8 , wherein the fluid-impermeable layer is formed from metal and configured to conduct electricity and maintain a rigidity of the bipolar plate.

12 . The redox flow battery system of claim 8 , wherein the negative electrode is formed from a layer of high surface area carbon particles deposited onto a first surface of the fluid-impermeable layer.

13 . The redox flow battery system of claim 8 , wherein the positive electrode is formed from a carbon or graphite felt heat-pressed onto a second surface of the fluid-impermeable layer, the second surface opposite of the first surface.

14 . The redox flow battery system of claim 8 , wherein the fluid-impermeable layer is formed from thermoplastic and separates the negative electrolyte from the positive electrolyte within the battery cell.

15 . The redox flow battery system of claim 14 , wherein the negative electrode is formed from a carbon sheet coupled to a first surface of the thermoplastic.

16 . The redox flow battery system of claim 15 , wherein the positive electrode is formed from a carbon or graphite felt coupled to a second surface of the thermoplastic, the second surface opposite of the first surface.

17 . The redox flow battery system of claim 16 , further comprising a conductive thread penetrating through a thickness of the bipolar plate and maintaining the coupling of the negative electrode to the first surface of the thermoplastic and the coupling of the positive electrode to the second surface of the thermoplastic and wherein the thermoplastic is melted and sealed around portions of the conductive thread extending through a thickness of the thermoplastic.

18 . The redox flow battery system of claim 8 , wherein the membrane separator is coupled to the negative electrode on a first side of the membrane separator and coupled to the positive electrode of the adjacent battery cell on a second side of the membrane separator, the second side opposite of the first side.

19 . A method for manufacturing a redox flow battery, comprising;
fabricating a bipolar plate assembly, the bipolar plate assembly including a non-conductive substrate coupled to a negative electrode on a first side and coupled to a positive electrode on a second, opposite side, the negative and positive electrodes spaced apart by a thickness of the non-conductive substrate.

20 . The method of claim 17 , further comprising fabricating the bipolar plate assembly by a roll-to-roll process.

Assignees

• Ess Technology Inc

Inventors

• Evans Craig E

Classifications

• H01M8/188 Primary

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

• H01M8/0204

  Non-porous and characterised by the material · CPC title

• H01M8/0213 Primary

  Gas-impermeable carbon-containing materials · CPC title

• H01M8/0202

  Collectors; Separators, e.g. bipolar separators; Interconnectors · CPC title

• H01M4/663

  containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres · CPC title