Method for Hydrophilicizing a Semifinished Element, and Electrode Element, Bipolar Element or Heat Exchanger Element Produced Thereby

Abstract

The invention relates to a method for hydrophilicizing a semi-finished element, in particular an electrode element, a bipolar element and/or a heat exchanger element, made of a plastic material or plastic composite material containing at least one thermoplastic and/or at least one thermosetting plastic. In order that the wettability of the component surface for aqueous media can be increased with smaller structure changes, with lower costs and with less effort, provision is made for the hydrophilicizing to be caused at least partially by applying carbon particles at least in sections on at least one surface of the semi-finished element and the carbon particles to be applied by rubbing, pressurised gas jet and/or by electrostatics at least in sections on the at least one surface in such manner that the carbon particles remain adhered to the surface.

Claims

1. A method for hydrophilicizing a semi-finished element, in particular an electrode element, a bipolar element and/or a heat exchanger element, made of a plastic material or plastic composite material containing at least one thermoplastic and/or at least one thermosetting plastic, in the case of which the hydrophilicizing is caused at least partially by applying carbon particles at least in sections on at least one surface of the semi-finished element and in the case of which the carbon particles are applied by rubbing, pressurised gas jet and/or by electrostatics at least in sections on the at least one surface in such manner that the carbon particles remain adhered to the surface.

2. The method according to claim 1, in the case of which, after applying carbon particles on the at least one surface for hydrophilicizing the semi-finished element, the excess carbon particles are removed at least predominantly from the at least one surface by tapping, shaking, blowing, rinsing and/or wiping.

3. The method according to claim 1, in the case of which carbon particles in the form of graphite, graphene, carbon nano tubes, carbon black and/or carbon fibres are used for hydrophilicizing.

4. The method according to claim 1, in the case of which hydrophilicizing takes place with carbon particles at a temperature of between 0° C. and 50° C., preferably between 5° C. and 40° C., in particular between 10° C. and 30° C.

5. The method according to claim 1, in the case of which, after applying the carbon particles on the at least one surface to be hydrophilicized, in particular after removing the carbon particles from the hydrophilicized surface, the grammage of the carbon particles on the surface is at least in sections less than 10,000 mg/m.sup.2, preferably less than 1,000 mg/m.sup.2, in particular less than 500 mg/m.sup.2.

6. The method according to claim 1, in the case of which at least 90% by weight of the carbon particles are smaller than 100 μm, preferably smaller than 10 μm, in particular smaller than 0.1 μm.

7. The method according to claim 1, in the case of which the carbon particles have a BET surface of between 50 m.sup.2/g and 10,000 m.sup.2/g, preferably between 250 m.sup.2/g and 2,500 m.sup.2/g, in particular between 500 m.sup.2/g and 1800 m.sup.2/g.

8. The method according to claim 1, in the case of which the oil adsorption number (ISO 4656:2012-07) of the carbon particles is between 10 ml/100 g and 1000 ml/100 g, in particular between 50 ml/100 g and 500 ml/100 g, in particular between 100 ml/100 g and 300 ml/100 g.

9. The method according to claim 1, in the case of which the at least one thermoplastic is selected from the group of polyolefins (e.g. polyethylene (PE), polypropylene (PP)), poly sulfides and poly sulfones (e.g. polyphenylene sulfide (PPS), polysulfone (PSU)), poly aryl ether ketones (e.g. poly ether ketone (PEK) and polyether ether ketone (PEEK)) and/or fluoroplastics (e.g. polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF)) and/or in the case of which the at least one thermosetting plastic is selected from the group of reaction resins (e.g. unsaturated polyester resins (UP resins), epoxide resins (EP resins), isocyanate resins, methacrylate resins (MA resins), phenacrylate resins (PHA resins) and/or condensation resins (e.g. phenol resins, amino resins, polyester resins).

10. The method according to claim 1, in the case of which between 25% by volume and 97% by volume, preferably between 45% by volume and 88% by volume, in particular between 53% by volume and 70% by volume, of the plastic composite material is formed by a, preferably electrically conductive, filler material.

11. The method according to claim 1, in the case of which as the at least one filler material of the plastic composite material, carbon particles, in particular in the form of graphite, graphene, carbon nano tubes, carbon black and/or carbon fibres arc used and in the case of which, preferably, the filler material at least substantially corresponds to the carbon particles for hydrophilicizing the at least one surface of the semi-finished element.

12. The method for manufacturing an electrode element, in particular an electrode plate, a bipolar element, in particular a bipolar plate, and/or a heat exchanger element, in particular a heat exchanger tube or a heat exchanger plate, from a semi-finished element, in the case of which a semi-finished element hydrophilicized according to claim 1, is further processed into an electrode element, in particular an electrode plate, a bipolar element, in particular a bipolar plate, and/or a heat exchanger element, in particular a heat exchanger tube or a heat exchanger plate, and/or in the case of which a semi-finished element is further processed into an electrode element, in particular an electrode plate, a bipolar element, in particular a bipolar plate, and/or a heat exchanger element, in particular a heat exchanger tube or a heat exchanger plate, and then is hydrophilicized according to claim 1.

13. The method according to claim 12, in the case of which the electrode element is an electrode element of an electrochemical cell, in particular of a redox flow battery or in the case of which the bipolar element is a bipolar element of an electrochemical cell, in particular of a redox flow battery.

14. An electrode element, in particular electrode plate, bipolar element, in particular bipolar plate, and/or heat exchanger element, in particular heat exchanger tube or heat exchanger plate, manufactured according to claim 12.

15. An electrochemical cell, in particular redox flow battery, with an electrode element, in particular electrode plate, or with a bipolar element, in particular bipolar plate, according to claim 14.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The invention is explained in more detail below on the basis of a drawing merely representing exemplary embodiments. In the drawing is shown:

[0047] FIG. 1 the hydrophilicizing according to the invention of a surface of a semi-finished element by rubbing in a schematic side view,

[0048] FIG. 2 the hydrophilicizing according to the invention of a surface of a semi-finished element by pressurised gas jet in a schematic side view, and

[0049] FIG. 3 the hydrophilicizing according to the invention of a surface of a semi-finished element by electrostatics in a schematic side view.

DESCRIPTION OF THE INVENTION

[0050] In FIG. 1, a method is schematically represented for hydrophilicizing a surface 1 to be treated of a flat semi-finished element 2, in particular of an electrode element, of a bipolar element and/or of a heat exchanger element, by rubbing in carbon particles 3, in particular in the form of graphite, graphene, carbon nano tubes, carbon black and/or carbon fibres. To do this, a rubbing element 4, for instance in the form of a stamp or plate, is moved over the surface 1 to be treated and namely preferably back and forth, with circular movements being particularly recommended. For the sake of simplicity, the rubbing element 4 can be driven by motor and be connected to the drive, not represented, via a rod element 5. In one possible configuration, the carbon particles 3 to be rubbed in can be guided to the surface 1 to be treated via a hollow rod element 5 and a central opening in the rubbing element 4. The carbon particles 3 applied to the surface 1 to be treated by the rubbing element 4 under a preferably adjustable pressure partially penetrate into the plastic of the surface 1 and thus remain adhered to the surface 1.

[0051] In FIG. 2, a method is schematically represented for hydrophilicizing a surface 1 to be treated of a flat semi-finished element 2, in particular of an electrode element, of a bipolar element and/or of a heat exchanger element, by pressurised gas jet of carbon particles 3, in particular in the form of graphite, graphene, carbon nano tubes, carbon black and/or carbon fibres. In this process, a two-substance nozzle 6 is moved over the surface 1 to be treated and namely preferably back and forth, with circular movements being particularly recommended. The carbon particles 3 are introduced via the two-substance nozzle 6 by way of an outer annual channel 7 and are entrained by a pressurised gas current 9, in particular by a pressurised air current, flowing out via a central opening 8. In this way, a jet 10 of carbon particles 3 is generated, which impinges upon the surface 1 to be treated at high speed such that the carbon particles 3 applied in this manner partially penetrate into the plastic of the surface 1 and thus remain adhered to the surface 1.

[0052] In FIG. 3, a method is schematically represented for hydrophilicizing a surface 1 to be treated of a flat semi-finished element 2, in particular of an electrode element, of a bipolar element and/or of a heat exchanger element, by electrostatic attraction of carbon particles 3, in particular in the form of graphite, graphene, carbon nano tubes, carbon black and/or carbon fibres. In this process, a charge, here a positive charge 11, is first applied to the surface 1 to be treated of the semi-finished element 2 which ensures a positive excess charge on the surface 1 of the semi-finished element 2. In contrast, a negative charge 12 has been applied to the carbon particles 3 and they have been introduced into a channel 13 from which the carbon particles 3 trickle out as a result of the potential difference and remain adhered partially electrostatically to the surface 1 to be hydrophilicized. In order to apply the carbon particles 3 extensively on the surface 1, the channel 13 with the carbon particles 3 can be moved over the surface 1 to be treated and namely preferably back and forth, with circular movements being particularly recommended.