Method for reducing electrolyte loss from an electrochemical cell

• US 4,414,291 A
• Filed: 05/25/1982
• Issued: 11/08/1983
• Est. Priority Date: 12/24/1980
• Status: Expired due to Term

• Current Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Breault, Richard D.
• Primary Examiner(s): Lefevour, Charles F.
• Application Number:
  US06/381,806
• Time in Patent Office: 532 Days
• Field of Search: 429/14, 429/26, 429/27, 429/29, 429/34, 429/46, 429/72, 429/120
• US Class Current: 429/434
• CPC Class Codes: H01M 8/04119 with simultaneous supply or evacuation of electrolyte; Humidifying or dehumidifying
• CPC Class Codes: H01M 8/04283 Supply means of electrolyte to or in matrix-fuel cells
• CPC Class Codes: H01M 8/241 with solid or matrix-supported electrolytes
• CPC Class Codes: H01M 8/2415 External manifolded battery stock
• CPC Class Codes: H01M 8/2484 characterised by external manifolds
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

In an electrochemical cell wherein during operation electrolyte evaporates into a reactant gas stream, the evaporated electrolyte, before it leaves the cell as a vapor in the reactant gas exhaust stream, is condensed from the gas stream by reducing the temperature of the reactant gas stream just before it exits the cell. The condensed electrolyte is taken up by the cell electrode and redistributed throughout the cell by diffusion and capillary action.

Claims

1. In a stack of electrochemical cells, each cell having electrolyte adjacent a gas diffusion type porous electrode wherein during operation said electrolyte evaporates into a reactant gas stream flowing through said cell in operable relationship to said electrode and to said electrolyte, the process of reducing electrolyte loss from said cells as a result of said evaporation comprising the step of cooling said gas stream in a condensation zone within each cell adjacent the reactant gas outlet of each cell so as to condense at lesat some of the electrolyte vapor from the gas stream back into the respective electrode of each cell prior to said gas stream leaving the cell, wherein said condensed-out electrolyte is redistributed within the cell by diffusion or bulk flow within the electrode.

2. The process according to claim 1 wherein said step of cooling includes reducing the amount of heat generated by a cell in the condensation zone by preventing the cell electrochemical reaction from occurring in that zone.

3. The process according to claim 2 wherein said step of cooling includes passing all of said reactant gas stream through the pores of a portion of said porous electrode disposed in said condensation zone.

4. The process according to claims 1, 2 or 3 wherein the electrolyte is phosphoric acid and said electrolyte is disposed within a matrix element.