Flexible graphite metal composite bipolar plate preparation method

Abstract

The present invention relates to the technical field of fuel cells, and discloses a flexible graphite metal composite bipolar plate preparation method, which comprises the following steps of carrying out stamping or isostatic pressing on a metal polar plate, wherein the metal polar plate is provided with first convex strips, a reduction flow field is formed between every two adjacent first convex strips, and the first convex strips are provided with grooves, and a coolant flow field is formed between the groove and the upper surface of the flexible graphite cathode plate, carrying out surface coating treatment on the obtained metal polar plate to form a metal anode plate, preparing a flexible graphite cathode plate, arranging second convex strips on the flexible graphite cathode plate, and forming an oxidation flow field between every two adjacent second convex strips, and carrying out bonding and curing treatment on the metal anode plate and the flexible graphite cathode plate by adopting a polar plate connection process, so as to complete the preparation of the flexible graphite metal composite bipolar plate. The method has the advantages of large-scale production, high processing efficiency, good toughness, high mechanical strength, good heat-conducting property, good sealing property, small thickness and corrosion resistance.

Description

technical field [0001] The invention relates to the technical field of fuel cells, in particular to a method for preparing a flexible graphite-metal composite bipolar plate. Background technique [0002] Fuel cell is a power generation device that directly converts chemical energy into electrical energy through electrochemical reaction of hydrogen and oxygen, and has a very broad market prospect. Fuel cells can be specifically divided into proton exchange membrane fuel cells, high temperature solid oxide fuel cells, alkaline fuel cells, phosphoric acid fuel cells and molten carbonate fuel cells. With the continuous development of new energy technologies, proton exchange membrane fuel cells using hydrogen as the main fuel have become a research hotspot in recent years. Because the energy conversion process does not need to go through the heat engine process, the energy conversion efficiency is not limited by the Carnot cycle, the power generation efficiency of the battery pa...

AI Technical Summary

Problems solved by technology

Existing bipolar plates are mainly divided into graphite bipolar plates (hard graphite bipolar plates and flexible graphite bipolar plates), composite material bipolar plates and metal bipolar plates; Strict, labor-intensive and time-consuming, and this type of bipolar plate is brittle, lacks toughness, and is difficult to use in batches; the thickness of the flexible graphite bipolar plate is relatively thick, and the thickness of the finished plate is generally about 2mm-3mm, resulting in a large fuel cell stack. It is not conducive to the improvement of the battery volume specific power; the corrosion resistance of the metal bipolar plate is poor, and the contact resistance between the plate and the membrane electrode is large, and surface coating is usually required to improve the corrosion resistance of the plate and reduce the contact resistance, which will lead to The cost of the plate is rising, and the corrosion resistance of the metal bipolar plate with surface coating is still far behind that of the graphite bipolar plate. The fuel cell stack assembled with the metal bipolar plate generally has a service life of 5000 hours, while the service life of fuel cell stacks assembled with graphite bipolar plates generally exceeds 15,000 hours, and the service life of metal bipolar plates is shorter

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