Operation of molten carbonate fuel cells with high electrolyte fill level

Patent metadata

Field	Value
Publication number	US-11888199-B2
Application number	US-202217677363-A
Country	US
Kind code	B2
Filing date	Feb 22, 2022
Priority date	Nov 26, 2019
Publication date	Jan 30, 2024
Grant date	Jan 30, 2024

Abstract

An elevated target amount of electrolyte is used to initially fill a molten carbonate fuel cell that is operated under carbon capture conditions. The increased target electrolyte fill level can be achieved in part by adding additional electrolyte to the cathode collector prior to start of operation. The increased target electrolyte fill level can provide improved fuel cell performance and lifetime when operating a molten carbonate fuel cell at high current density with a low-CO 2 content cathode input stream and/or when operating a molten carbonate fuel cell at high CO 2 utilization.

First claim

The invention claimed is:

1. A method for producing electricity in a molten carbonate fuel cell comprising a lithium-containing electrolyte, the method comprising: operating a molten carbonate fuel cell comprising an anode, a matrix, and a cathode with a cathode input stream comprising CO 2 at an average current density of 120 mA/cm 2 or more and a CO 2 utilization of 90% or more, the molten carbonate fuel cell further comprising a combined target electrolyte fill level of 70 vol % or more of a combined matrix pore volume and cathode pore volume.

2. The method of claim 1 , wherein the cathode input stream comprises 5.0 vol % or less of CO 2 , or wherein a cathode exhaust comprises 2.0 vol % or less of CO 2 , or wherein the molten carbonate fuel cell is operated at a transference of 0.95 or less, or a combination of two or more thereof.

3. The method of claim 1 , wherein the electrolyte comprises a non-eutectic mixture, or wherein a lithium carbonate content of the electrolyte is greater than a corresponding eutectic composition by 10 wt % or more.

4. The method of claim 1 , wherein the average current density is 150 mA/cm 2 or more.

5. The method of claim 1 , wherein the molten carbonate fuel cell is operated for a cumulative time of 50 hours or more.

6. The method of claim 1 , wherein a target cathode electrolyte fill level comprises 85 vol % to 140 vol % of the cathode pore volume.

7. The method of claim 1 , wherein the combined target electrolyte fill level is 85 vol % to 128 vol %.

Assignees

• Exxonmobil Technology & Engineering Company
• Fuelcell Energy Inc

Inventors

• Rosen Jonathan
• Elsen Heather A
• Kiss Gabor
• Lamberti William A
• Horn William C
• Zhang Anding
• Geary Timothy C
• Franco Adam
• Hilmi Abdelkader

Classifications

• H01M8/142 Primary

  with matrix-supported or semi-solid matrix-reinforced electrolyte · CPC title

• H01M8/0202

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

• H01M8/0289

  Means for holding the electrolyte (solid polymer electrolytes H01M8/1018) · CPC title

• H01M8/04283

  Supply means of electrolyte to or in matrix-fuel cells · CPC title

• H01M8/04902

  of the individual fuel cell · CPC title