Method for producing a solid ceramic fuel cell
View Patent ↗According to a method for producing a solid ceramic fuel cell, a solid electrolyte layer is gas-tightly deposited on an electrode inside a coating chamber, using a plasma spraying technique. The pressure inside the coating chamber is set at less than approximately 15 mbar for this purpose. A coating material is powder form, preferably with a particle diameter of significantly less than 10 μm, is finely dispersed in the plasma jet in such a way that the individual particles are isolated from each other when they meet the electrode. This enables a very homogenous and impervious solid electrolyte layer to be deposited.
1. A process for producing a solid oxide fuel cell, including a solid electrolyte layer arranged between two porous electrodes, comprising:
applying the solid electrolyte layer in gastight form to one of the electrodes via a plasma-spraying process in a coating chamber in which the pressure is less than 15 mbar, wherein individual particles of a coating material are entrained in a plasma jet, and wherein the particles are thinly distributed in the plasma jet in such a manner that they are applied to the one of the electrodes in substantially isolated form.
2. The process as claimed in claim 1 , further comprising:
producing a continuous layer after the plasma jet has passed over the electrode a plurality of times.
3. The process as claimed in claim 2 , wherein the layer is continuous after the plasma jet has passed over the electrode about 20 to 60 times.
4. The process as claimed in claim 1 , wherein the total layer thickness of the solid electrolyte layer is between 5 μm and 30 μm.
5. The process as claimed in claim 1 , wherein the plasma jet on the electrode includes a jet diameter of between 30 and 50 cm.
6. The process as claimed in claim 1 , wherein a pulverulent coating material with a mean particle diameter of less than 20 μm is introduced into the plasma jet.
7. The process as claimed in claim 1 , wherein the leak rate of the solid electrolyte layer is less than 10*10 −4 mbar l/sec/cm 2 .
8. The process as claimed in claim 1 , wherein the density of the coating is set by varying the process parameters.
9. The process as claimed in claim 8 , wherein the density is set by selecting the mean particle size.
10. The process as claimed in claim 1 , further comprising: applying an interconnector as a further layer via the plasma-spraying process.
11. The process as claimed in claim 1 , wherein at least one of the electrodes is produced via the plasma-spraying process.
12. The process as claimed in claim 1 , wherein the process parameters are varied during the coating.
13. The process as claimed in claim 1 , wherein the fuel cell is designed as a tubular hollow body.
14. The process as claimed in claim 3 , wherein the layer has a layer thickness of 5 μm to 10 μm.
15. The process as claimed in claim 1 , wherein the total layer thickness of the solid electrolyte layer is between 5 μm and 30 μm.
16. The process as claimed in claim 1 , wherein the total layer thickness of the solid electrolyte layer is between 5 μm and 30 μm.
17. The process as claimed in claim 4 , wherein the plasma jet on the electrode includes a jet diameter of 40 cm.
18. The process as claimed in claim 2 , wherein the plasma jet on the electrode includes a jet diameter of between 30 and 50 cm.
19. The process as claimed in claim 3 , wherein the plasma jet on the electrode includes a jet diameter of between 30 and 50 cm.
20. The process as claimed in claim 1 , wherein a pulverulent coating material with a mean particle diameter of less than 10 μm is introduced into the plasma jet.
21. The process as claimed in claim 1 , wherein the leak rate of the solid electrolyte layer is less than 2.3*10 −4 mbar l/sec/cm 2 .
22. A method for producing a solid oxide fuel cell, including a solid electrolyte layer arranged between two porous electrodes, comprising:
applying the solid electrolyte layer in gastight form to one of the electrodes via a plasma-spraying process in a coating chamber in which the pressure is less than 15 mbar, wherein particles of a coating material are dispersed in the plasma jet in such a manner that they are applied to the one of the electrodes in substantially isolated form.
23. The process as claimed in claim 22 , further comprising:
producing a continuous layer by passing the plasma jet over the at least one electrode a plurality of times.
24. The process as claimed in claim 23 , wherein the layer is continuous after the plasma jet has passed over the electrode about 20 to 60 times.