Title: Operating a redox flow battery with a negative electrolyte imbalance

Abstract

Loss of flow battery electrode catalyst layers during self-discharge or charge reversal may be prevented by establishing and maintaining a negative electrolyte imbalance during at least parts of a flow battery's operation. Negative imbalance may be established and/or maintained actively, passively or both. Actively establishing a negative imbalance may involve detecting an imbalance that is less negative than a desired threshold, and processing one or both electrolytes until the imbalance reaches a desired negative level. Negative imbalance may be effectively established and maintained passively within a cell by constructing a cell with a negative electrode chamber that is larger than the cell's positive electrode chamber, thereby providing a larger quantity of negative electrolyte for reaction with positive electrolyte.

Inventors:

Pham, Quoc; Chang, On; Durairaj, Sumitha

Issue Date:

Tue Mar 31 00:00:00 EDT 2015

Research Org.:

EnerVault Corporation, Sunnyvale, CA (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1177112

Patent Number(s):

8993183

Application Number:

14/095,362

Assignee:

EnerVault Corporation (Sunnyvale, CA)

Patent Classifications (CPCs):

H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01M - PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY

Y - NEW / CROSS SECTIONAL TECHNOLOGIES Y02 - TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE Y02E - REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

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H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01M - PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY

H01M8/04186 - of liquid-charged or electrolyte-charged reactants
H01M8/04228 - during shut-down
H01M8/04303 - applied during shut-down
H01M8/04447 - {of anode reactants at the inlet or inside the fuel cell}
H01M8/04455 - {of cathode reactants at the inlet or inside the fuel cell}
H01M8/04798 - {of fuel cell reactants}
H01M8/04955 - Shut-off or shut-down of fuel cells
H01M8/188 - {by recharging of redox couples containing fluids
H01M8/20 - Indirect fuel cells, e.g. fuel cells with redox couple being irreversible

Y - NEW / CROSS SECTIONAL TECHNOLOGIES Y02 - TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE Y02E - REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

Y02E60/50 - Fuel cells

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DOE Contract Number:  

OE0000225

Resource Type:

Patent

Resource Relation:

Patent File Date: 2013 Dec 03

Country of Publication:

United States

Language:

English

Subject:

25 ENERGY STORAGE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY