Production method of carbon-based composite die-pressing bipolar plateTechnical Field
The invention relates to the technical field of bipolar plate production, in particular to a production method of a carbon-based composite molded bipolar plate.
Background
Currently, bipolar plates in the industry are mainly classified into metal bipolar plates and graphite bipolar plates, wherein the graphite bipolar plates are further classified into hard graphite bipolar plates and flexible graphite bipolar plates, and the development of the metal bipolar plates is in a stagnation state at present.
In the stack operating environment, three aspects cause fatal damage to the metal bipolar plate: acid corrosion, galvanic corrosion, and the shape of the plate at high temperature), so that the metallic bipolar plate has a short service life; the hard graphite bipolar plate has low bending strength, and the process is a machine processing flow channel, so that the efficiency and the cost are difficult to keep up with the market; the flexible graphite bipolar plate has the defects of large resistance, very poor breaking strength, poor compression molding precision and the like. Therefore, the bipolar plates currently produced have the following disadvantages: low breaking strength, non-corrosion resistance, high cost and the like, and can not be produced in batch with high efficiency.
Disclosure of Invention
One object of the present invention is: provides a production method of a carbon-based composite die-pressed bipolar plate, which is used for solving the problems in the prior art.
In order to achieve the purpose, the invention adopts the following technical scheme:
a production method of a carbon-based composite molded bipolar plate comprises the following steps:
stirring graphite powder and carbon black uniformly;
introducing resin, and stirring until the color is uniform;
adding carbon nano tubes, and uniformly stirring to obtain a mixture;
pumping the mixture into a mold, and pressurizing and heating the mold after the mold is closed;
maintaining the pressure and keeping the shape after the set pressure is reached;
after reaching the set temperature, the model is converted into a molding mode;
standing for waiting for the temperature to decrease, and taking out a finished product;
and (5) placing the finished product into a jig for shape keeping and cooling to obtain the bipolar plate.
As a preferred technical scheme, the part ratio of graphite powder, carbon black, resin and carbon nano tubes is 4:1:4:1.
as a preferable technical scheme, the pressure is set to be 10MPa-50MPa.
As a preferred technical scheme, the set temperature is 100-200 degrees.
As a preferable technical solution, the molding mode is to mold the shape of the product according to the requirement.
As a preferred technical scheme, the temperature value reduced is 20-30 degrees.
The invention has the beneficial effects that: the bipolar plate produced by the production method of the carbon-based composite die-pressing bipolar plate has the advantages of chemical corrosion resistance, electric corrosion resistance, low thermal expansion coefficient, low production cost, low die molding cost, high production efficiency, high strength, low resistance, stable performance and suitability for mass production, and can be used for a long time without expansion or deformation in a high-temperature environment.
Detailed Description
The technical solution of the present invention is further explained by the following embodiments.
In this embodiment, a method for producing a carbon-based composite molded bipolar plate specifically comprises the following steps of mixing graphite powder, carbon nanotubes, carbon black and resin according to a ratio of 40:10:10:40, stirring graphite powder and carbon black uniformly, introducing resin, continuously stirring uniformly, adding carbon nano tubes, continuously stirring uniformly to obtain a mixture, pumping the mixture with rated weight into a mold, carrying out mold closing treatment on the mold, heating while pressurizing until the internal pressure value reaches the rated value, namely the set value in 10Mpa-50Mpa (the specific value is set according to the internal area size of the mold), maintaining the pressure and maintaining the shape, gradually heating to 160 ℃, then reaching the thermosetting temperature and converting to the molding shape, heating and solidifying the mixture in the mold to form the cavity molding of the mold due to the characteristics of the resin, then waiting for the temperature of the mold to fall to the set temperature in 20-30 ℃ (the specific value is set according to the internal area size of the mold), opening the mold and taking out the finished product, finally putting the finished product into a jig, maintaining the shape and cooling, and taking out the finished product
The bipolar plate produced by the production method of the carbon-based composite die-pressed bipolar plate has the following advantages:
1. compared with a metal bipolar plate, the product has the advantages of chemical corrosion resistance, electric corrosion resistance, low thermal expansion coefficient and low cost;
2. compared with the hard graphite bipolar plate, the flow channel of the product is molded by a mold, has low cost and high efficiency, and is suitable for mass production;
3. compared with flexible graphite bipolar plates, the product has high strength, relatively low resistance and high production efficiency, and the material cannot expand or deform even being used for a long time in a high-temperature environment, and has stable performance and low cost.
It should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention and the technical principles used, and any changes or substitutions which can be easily conceived by those skilled in the art within the technical scope of the present invention disclosed herein should be covered within the protective scope of the present invention.