Method for mounting oxygen-consuming electrodes in electrochemical cells and electrochemical cells

Patent metadata

Field	Value
Publication number	US-2017088961-A1
Application number	US-201615377255-A
Country	US
Kind code	A1
Filing date	Dec 13, 2016
Priority date	Dec 10, 2010
Publication date	Mar 30, 2017
Grant date	—

Abstract

Method for the gastight and liquid-tight installation of oxygen consuming electrodes in an electrolysis apparatus, and electrolysis apparatus for use in chloralkali electrolysis, in which particular regions are covered with an additional film having a composition comparable to the oxygen-consuming electrodes.

First claim

1 .- 15 . (canceled)

16 . A method for the gastight and liquid-tight installation of one or more joining oxygen-consuming electrodes in an electrochemical half cell, comprising covering creased regions and/or cracked regions of the oxygen-consuming electrodes and/or abutting edge regions and/or overlap regions of adjacent oxygen-consuming electrodes occurring when the oxygen-consuming electrodes are brought into juxtaposition with a frame of a gas compartment of the cell with an additional film which has a composition comparable to the oxygen-consuming electrodes and is thinner than the layer thickness of the oxygen-consuming electrode.

17 . The method according to claim 1 , wherein the additional film has the same catalytically active material as the oxygen-consuming electrode.

18 . The method according to claim 1 , wherein the additional film and/or the oxygen-consuming electrodes are, independently of one another, based on a fluorinated polymer and a silver-containing catalytically active material.

19 . The method according to claim 1 , wherein the additional film and/or the oxygen-consuming electrodes are, independently of one another, based on polytetrafluoroethylene (PTFE) and a silver-containing catalytically active material.

20 . The method according to claim 19 , wherein the catalytically active component in the additional film and/or in the oxygen-consuming electrodes comprises silver, silver(I) oxide, silver(II) oxide, or mixtures thereof.

21 . The method according to claim 19 , wherein the content of the catalytically active component in the additional film comprises at least 50% by weight of silver oxide.

22 . The method according to claim 19 , wherein the content of the catalytically active component in the additional film comprises at least 80% by weight of silver oxide.

23 . The method according to claim 1 , wherein the additional film and/or the oxygen-consuming electrodes comprises mixtures which, independently of one another, comprise, as catalytically active component, from 70 to 95% by weight of silver oxide, from 0-15% by weight of silver metal powder and from 3-15% by weight of a fluorinated polymer.

24 . The method according to claim 23 , wherein the fluorinated polymer is polytetrafluoroethylene (PTFE).

25 . The method according to claim 1 , wherein the additional film and the oxygen-consuming electrodes are pressed together after application of the additional film.

26 . The method according to claim 1 , wherein the additional film and the oxygen-consuming electrodes join together at their contact points after application of the additional film when the cell is started up.

27 . The method according to claim 1 , wherein the additional film has a layer thickness of from 10 μm to 800 μm.

28 . The method according to claim 1 , wherein the additional film has a layer thickness of from 50 μm to 600 μm.

29 . The method according to claim 1 , wherein the oxygen-consuming electrodes have a layer thickness of from 0.1 to 0.8 mm.

30 . The method according to claim 1 , wherein the oxygen-consuming electrodes have a layer thickness of from 0.2 to 0.7 mm.

31 . An electrochemical cell ( 2 ) having one or more adjoining oxygen-consuming electrodes, wherein the oxygen-consuming electrodes have creased regions, and/or cracked regions of the oxygen-consuming electrodes and/or abutting edge regions and/or overlap regions of adjacent oxygen-consuming electrodes and occurring upon installation on the frame of the gas compartment of the cell and wherein at least one of these regions are covered with an additional film which has a composition comparable to the oxygen-consuming electrodes and is thinner than the layer thickness of the oxygen-consuming electrode.

32 . The electrochemical cell according to claim 31 , wherein the oxygen-consuming electrodes comprises a gas diffusion layer which comprises a fluorinated polymer.

33 . The electrochemical cell according to claim 31 , wherein the oxygen-consuming electrodes and/or the additional film comprises an additional support element which comprises an electrically conductive flexible textile structure.

34 . An electrochemical cell obtained by installing the oxygen-consuming electrodes according to the method according to claim 1 .

35 . A chloralkali electrolysis apparatus comprising the electrochemical cell according to claim 34 .

Assignees

• Covestro Deutschland Ag
• Uhdenora Spa

Inventors

• Bulan Andreas
• Grossholz Michael
• Kiefer Randolf
• Woltering Peter

Classifications

• H01M4/88

  Processes of manufacture · CPC title

• C25B1/34 Primary

  Simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine, e.g. by chlor-alkali electrolysis · CPC title

• C25B11/095 Primary

  at least one of the compounds being organic · CPC title

• C25B9/19

  with diaphragms · CPC title

• C25B11/031

  Porous electrodes · CPC title