Methods and systems for pretreating bipolar plate and use thereof in redox flow battery

Patent metadata

Field	Value
Publication number	US-2023378482-A1
Application number	US-202318363576-A
Country	US
Kind code	A1
Filing date	Aug 1, 2023
Priority date	Feb 26, 2021
Publication date	Nov 23, 2023
Grant date	—

Abstract

Systems and methods are provided for electrochemical and/or chemical pretreatment of bipolar plates, for example, for plating electrodes in redox flow batteries. In one example, a method may include pretreating a bipolar plate for the redox flow battery by disrupting a surface of the bipolar plate. In some examples, pretreating the bipolar plate may include positioning the bipolar plate within the redox flow battery, and thereafter charging the redox flow battery at multiple discrete plating current densities for each of one or more initial charging cycles to electrochemically etch the surface. In additional or alternative examples, pretreating the bipolar plate may include soaking the bipolar plate in solution to chemically treat the surface. In this way, the bipolar plate may be pretreated via electrochemical etching and/or chemical treatment so as to reduce electrochemical performance losses and dendrite formation in the redox flow battery.

First claim

1 . A method for a redox flow battery, the method comprising:
pretreating a bipolar plate for the redox flow battery by disrupting at least one surface of the bipolar plate; and initiating charge cycling of the redox flow battery, wherein the redox flow battery includes an electrode compartment, the electrode compartment housing the pretreated bipolar plate upon initiation of charge cycling.

2 . The method of claim 1 , wherein pretreating the bipolar plate by disrupting the at least one surface comprises:
positioning the bipolar plate within the electrode compartment; and charging the redox flow battery at multiple discrete plating current densities for each charging cycle of one or more initial charging cycles to electrochemically etch the at least one surface, and wherein initiating charge cycling comprises charging the redox flow battery at a single plating current density for each charging cycle following the one or more initial charging cycles to uniformly plate a plating electrode housed in the electrode compartment.

3 . The method of claim 2 , wherein the one or more initial charging cycles comprises only one initial charging cycle.

4 . The method of claim 2 , wherein each of the multiple discrete plating current densities increase sequentially.

5 . The method of claim 1 , wherein the at least one surface is pristine and unetched prior to pretreatment; and
wherein the at least one surface is etched following pretreatment.

6 . The method of claim 1 , further comprising preforming iron plating at a plating electrode housed in the electrode compartment following pretreatment and prior to charge cycling.

7 . The method of claim 1 , wherein pretreating the bipolar plate by disrupting the at least one surface comprises:
cleaning the bipolar plate with isopropyl alcohol; and soaking the cleaned bipolar plate in solution for an extended duration to chemically treat the at least one surface.

8 . The method of claim 7 , wherein the solution comprises a ferric chloride solution.

9 . The method of claim 7 , wherein the extended duration is at least 12 hours.

10 . The method of claim 1 , further comprising:
cleaning the bipolar plate by soaking in acidic solution after pretreating the bipolar plate and before initiating charge cycling.

11 . A redox flow battery system, comprising:
positive and negative electrode compartments respectively housing positive and negative electrodes; a first bipolar plate positioned in the negative electrode compartment and in fluidic communication with the negative electrode; and a second bipolar plate positioned in the positive electrode compartment and in fluidic communication with the positive electrode, wherein a surface of the first bipolar plate facing toward the negative electrode is etched and roughened, and wherein metal plating formed on the surface is substantially free of cracking and excess particulates and flakes.

12 . The redox flow battery system of claim 11 , wherein the surface is etched and roughened by each of performing step charging of the redox flow battery system at a plurality of sequentially increasing plating current densities and soaking the surface in solution.

13 . The redox flow battery system of claim 11 , wherein the first bipolar plate is formed by injection molding or compression molding a graphite composite starting material.

14 . The redox flow battery system of claim 11 , wherein the redox flow battery system is an all-iron hybrid redox flow battery system.

Assignees

• Ess Technology Inc

Inventors

• Song Yang
• Wu Yan
• Thompson Brady

Classifications

• H01M8/0247 Primary

  characterised by the form (characterised by a channel configuration H01M8/0258) · CPC title

• H01M8/0228

  in the form of layered or coated products · CPC title

• H01M8/188 Primary

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

• Y02E60/50

  Fuel cells · CPC title