Surface modification method for dual polar plates of proton exchange membrane fuel cell

Abstract

The invention relates to a method for surface modification for a bipolar plate of a proton exchange membrane fuel cell in the technical field of energy resources. The bipolar plate is composed of a surface modification layer and substrate stainless steel. By adopting a method of ion injection, copper ions are injected into a stainless steel thin plate, an injection layer is formed in a range of dozens of nanometer on the surface of the stainless steel thin plate, and finally a modified stainless steel bipolar plate is obtained. The invention has the advantages that the corrosion resistance performance of a metallic bipolar plate can be further improved, the contact resistance of the metallic bipolar plate with a gas diffusion layer (carbon paper) can be reduced, a thinner bipolar plate can be produced, and the weight ratio energy and the volume ratio energy of a fuel cell can be increased, so as to satisfy the development requirement on the proton exchange membrane fuel cell.

Description

technical field [0001] The invention relates to a method for modifying the surface of a pole plate in the technical field of fuel cells, in particular to a method for modifying the surface of a 316L stainless steel bipolar plate of a proton exchange membrane fuel cell. Background technique [0002] Proton exchange membrane fuel cell (PEMFC) is a fuel cell with perfluorosulfonic acid solid polymer membrane as electrolyte, hydrogen or purified reformed gas as fuel, air or oxygen as oxidant, and its electrode reaction is similar to other acidic electrolyte fuel cells . Under the action of the catalyst, hydrogen reacts at the anode under the action of the catalyst to generate electrons and hydrogen ions. The electrons generated by the electrode reaction reach the cathode through the external circuit, and the hydrogen ions reach the cathode through the electrolyte membrane. Oxygen, hydrogen ions and electrons are at the cathode. Reaction occurs to generate water, and most of the...

AI Technical Summary

Problems solved by technology

Gold and nickel plates are used in metal bipolar plates of proton exchange membrane fuel cells due to their excellent corrosion resistance and low surface contact resistance, but their disadvantages are high cost and great difficulty in commercial production

[0006] Found through document retrieval to prior art, (H.Wang et al.) " Thermally nitrided stainless steel for polymer electrolyte " published on " Journal of Power Sources " (Energy magazine) (2004 138 period 79-85 pages) Membrane fuel cell bipolar plate Part 2: Beneficial modification of passive layer on AISI446" (Thermal nitriding stainless steel used as a proton exchange membrane fuel cell 2: beneficial modification of passive layer on AISI446 stainless steel) pointed out that nitriding at 1100 ° C for 2 hours can Significantly improve the corrosion resistance of stainless steel, but its disadvantage is that too high temperature will cause thermal deformation of the stamped stainless steel bipolar plate

Although its corrosion potential has moved positively and the passivation current has decreased, the TiN coating has certain coating defects. From the perspective of long-term working environment, the anti-corrosion performance is limited.

[0008] In summary, two major challenges in the application of metal bipolar plates—corrosion resistance and electrical conductivity—still hinder their commercial production.

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