Separator plate with periodic surface structures in the nanometer to micrometer range

Patent metadata

Field	Value
Publication number	US-2021288336-A1
Application number	US-202117195506-A
Country	US
Kind code	A1
Filing date	Mar 8, 2021
Priority date	Mar 10, 2020
Publication date	Sep 16, 2021
Grant date	—

Abstract

The present disclosure relates to a separator plate for an electrochemical system, wherein the separator plate has, at least in some regions, periodic surface structures with a mean spatial period of less than 10 μm. The disclosure additionally relates to a method for producing a separator plate for an electrochemical system, comprising the steps: providing a separator plate; irradiating the separator plate by means of a pulsed laser, wherein a pulse duration of the laser pulses is less than 1 ns; and creating periodic surface structures on the separator plate by way of the laser radiation.

First claim

1 . A separator plate for an electrochemical system, wherein the separator plate has, at least in some regions, periodic surface structures with a mean spatial period of less than 10 um.

2 . The separator plate according to claim 1 , wherein the surface structures comprise depressions which extend substantially parallel to one another.

3 . The separator plate according to claim 2 , wherein the depressions have:
a depth of at least 8 nm and/or at most 0.5 μm; and/or a width of at least 0.1 um and/or at most 2 μm; and/or a period in one spatial direction of at least 0.3 um and/or at most 3 μm.

4 . The separator plate according to claim 1 , wherein the separator plate is surface-treated by laser in the region of the periodic surface structures.

5 . The separator plate according to claim 1 , wherein the surface structures are arranged periodically with respect to one another at least in one spatial direction.

6 . The separator plate according to claim 1 , wherein an oxygen content of the surface material is greater in the region of the periodic surface structures than outside of the periodic surface structures.

7 . The separator plate according to claim 1 , wherein at least the regions provided with the periodic surface structures are provided with a coating at least in some sections and the coating increases the electrical conductivity.

8 . The separator plate according to claim 7 , wherein the coating comprises one or more of the following substances or alloys thereof: electrically conductive oxides, carbon, electrically conductive carbon layers, noble metals, metals, metal nitrides, metal carbides, metal borides, metal silicides, and/or silicon carbide.

9 . The separator plate according to claim 1 , having a plurality of webs and channels formed between the webs, wherein the webs have the surface structures at least in some sections, and/or wherein rear webs are formed on the surface of the separator plate opposite the channels, wherein the rear webs have the surface structures at least in some sections.

10 . The bipolar plate comprising two separator plates according to claim 9 , wherein the webs form a contact surface for bearing against a diffusion layer, and/or the rear webs form a contact surface for bearing against one another.

11 . The bipolar plate according to claim 10 , wherein an electrical resistance in the region of the contact surface between the webs and the gas diffusion layer and/or between the rear webs of the two separator plates is reduced by the surface structures.

12 . A method for producing a separator plate for an electrochemical system, comprising the steps:
providing a separator plate; irradiating the separator plate by means of a pulsed laser, wherein a pulse duration of the laser pulses is less than 1 ns; and creating periodic surface structures on the separator plate by way of the laser radiation.

13 . The method according to claim 12 , wherein the laser radiation is linearly polarized.

14 . The method according to claim 13 , wherein the surface structures are oriented perpendicular to a polarization direction of the incident laser radiation.

15 . The method according to claim 12 , wherein a mean spatial period of the surface structures is at least 2% and/or at most 200%, of the laser wavelength used.

16 . The method according to claim 12 , wherein a beam diameter or a smallest lateral size of the laser beam is at least 20 μm.

17 . The method according to claim 12 , wherein additionally at least the regions provided with the periodic surface structures are coated with a coating at least in some sections, and the coating increases the electrical conductivity.

18 . The method according to claim 12 , wherein the separator plate has a plurality of webs and channels formed between the webs, wherein, at least on one surface of the separator plate, at least the webs and/or the rear webs formed as the rear side of the channel bottoms are irradiated with the laser substantially across the entire surface and/or in some sections, and the surface structures are created on the webs and/or on the rear webs.

19 . The method according to claim 12 , wherein said plurality of periodic surface structures is created within a spatially contiguous projection of the laser radiation onto the separator plate.

20 . The method according to claim 19 , wherein the periodic surface structures are brought about by optical interference of the incident laser radiation with an electromagnetic surface wave in the material of the separator plate that is generated by the laser pulse.

Assignees

• Reinz Dichtungs Gmbh

Inventors

• Gaugler Bernd
• Grafl Dieter
• Wenzel Stephan

Classifications

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• H01M8/0258

  characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant · CPC title

• H01M8/0202 Primary

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

• B23K26/352

  for surface treatment · CPC title

• H01M8/026 Primary

  characterised by grooves, e.g. their pitch or depth · CPC title