Graphite bipolar plate is the most commonly used stack bipolar plate at present. It is the core component of the hydrogen energy vehicle stack. The bipolar plate is composed of a polar plate and a flow field. Its main functions are gas distribution, current collection, heat conduction, and sealing. . It has good chemical stability at room temperature, acid and alkali resistance, and corrosion resistance of organic solvents. The graphite bipolar plate has good electrical conductivity, thermal conductivity, stability, airtightness, and other properties, the thickness of the graphite bipolar plate is good, and the process is more advanced. Our graphite bipolar plates can be customized according to customer needs, with high strength, high-temperature resistance, oxidation resistance, excellent electrical and thermal conductivity, and graphite bipolar plates with different specifications.
Self-lubricating rod graphite battery plate fuel cell graphite bipolar plate can be customized and processed, directly supplied by manufacturers, with many specifications; suitable for the petrochemical industry, machinery industry, metallurgical industry, aerospace, and scientific research, and other fields. Graphite material fixed carbon more than 99.9%.
Main Specifications of graphite bipolar plates:
Air leakage coefficient: (minimum thickness 03mm, 1kg negative pressure airtight) Compressive strength: >100Mpa Bending strength: >50MPa Shore hardness: 60SSH
Recommended operating temperature: 150-180°C
Graphite material application：
Graphite materials can be used as refractory materials, conductive materials, wear-resistant lubricating materials, widely used in petrochemical, hydrometallurgy, acid-base production, synthetic fiber, papermaking, and other industrial sectors, which can save a lot of metal materials, graphite materials can be used for casting, Sand turning, stamping and high-temperature metallurgical materials can be used in the atomic energy industry and national defense industry, and can also prevent boiler scaling. It can be used as pencil lead, pigment, and polishing agent. Graphite materials can be used as electrodes and graphite gradually replaces copper as the material for EDM electrodes.
Customized advantages of graphite bipolar plates for hydrogen fuel cells:
1. Strong processing strength and mass production capacity
We have been engaged in the customization of graphite products for more than ten years. We are a professional graphite supplier integrating R&D, sales, production, and integration. We have dozens of sets of fully automated production equipment and high-precision testing equipment. We can provide professional various industries according to customer needs. Application solutions and various types and specifications of raw materials.
2. Upgrade of processing technology, innovation in the graphite bipolar plate industry
In recent years, the company has focused on the research and development of hydrogen fuel cell bipolar plates and has made major breakthroughs in production costs and processing techniques. Professional automated production lines and high-precision diversified testing equipment have also been added to the production equipment to provide the industry with high precision, Graphite bipolar plate with high-cost performance.
3. The product has high accuracy and guaranteed quality
All kinds of graphite products, exquisite processing technology, extremely high processing accuracy, high product qualification rate, ideal customer satisfaction, professional testing equipment, quality control, adhere to the mandatory inspection of each product leaving the factory to ensure product quality assurance.
4. Fast delivery and good after-sales service
In-depth cooperation with Chinese raw material suppliers, our company is also a Japanese graphite company, which can save the time and cost of purchasing raw materials around the world. The professional technical team can provide a full set of graphite product solutions according to customer needs. The processing speed is fast, and the delivery can be made according to the customer's order.
Graphite bipolar plate production process:
At present, the application of fuel cell systems in the market is mainly commercial vehicles, and the core component of fuel cell stacks is mainly graphite electrode stacks. From the perspective of future development, graphite bipolar plates will still occupy the commercial vehicle market for a long time. larger share. So why does the graphite bipolar plate occupy such a large market share, and how does it change from graphite to bipolar plate step by step?
According to the fuel cell bipolar plate performance requirements in the "Fuel Cell Technical Team Roadmap" report issued by the US Department of Energy in 2017:
The cost, mechanical properties, air permeability, corrosion resistance, electrical conductivity and surface contact resistance of the graphite bipolar plate production process have strict requirements as the core indicators of the bipolar plate. Therefore, the selection of raw materials and process processing of the graphite bipolar plate process affects whether it can meet the needs of the final target market.
According to different process requirements, graphite can be made into powder, coil, sheet, and emulsion, but the raw materials for the production process of graphite bipolar plate are mainly divided into three categories:
Graphite powder: a substance with a very sensitive chemical reaction, its resistivity will change in different environments, depending on whether the graphite powder can ensure the uninterrupted graphite powder in an insulating object. High-temperature resistance, chemical stability, plasticity, and thermoplastic resistance are all good.
Expanded graphite: a loose and porous worm-like substance obtained from natural graphite flakes through intercalation, water washing, drying and high-temperature expansion. In addition to the excellent properties of natural graphite itself, it also has the characteristics of softness, compression resilience, adsorption, and radiation resistance than natural graphite does not have. Expanded graphite can instantly expand 150-300 times in volume when exposed to high temperatures.
Flake graphite: It is natural crystalline graphite with complete crystallization. It is like fish phosphorus, belongs to the hexagonal crystal system, has a layered structure, is thin and has good toughness, excellent physical and chemical properties, and has good thermal conductivity, electrical conductivity, and heat resistance shock resistance, corrosion resistance, etc.
The source cited the analysis report of the two types of processes published by AFCC in Canada in 2017:
The expanded graphite sheet is calendered, formed, and removed, and then enters the resin impregnation, vulcanization, bonding, and sealing vulcanization process, and finally forms a bipolar plate product.
The production process of graphite bipolar plate has the following characteristics:
It can well meet the requirements of the shape, surface geometry, and mechanical size of the plate;
Due to the continuity of the expanded graphite material, it has high electrical and thermal conductivity;
The required surface hydrophobicity needs to be solved by co-processing of process and material;
If the rolling process is used, its design accuracy and process accuracy should be further improved;
The post-processing of clamping pressure, resin ratio, and surface contact resistance is the key to affecting the performance of the electrode plate;
First, the mixed material of graphite powder and resin is prepared, then the mixed material and mold are pre-molded, followed by molding and vulcanization, and finally, bonding, sealing, and curing are performed to form a product.
At present, the process has the following characteristics:
1. It can well meet the requirements of the shape, surface geometry, and mechanical size of the plate;
2. Since the mixed particles block the continuity of the graphite material, the conductivity should be further improved under high current;
3. To meet the needs of surface hydrophobicity, it needs to be solved by co-processing of technology and materials;
4. The ratio and selection of resin, vulcanization time, and post-treatment of surface contact resistance are the keys to affecting the performance of the electrode plate.
Judging from the current development of the hydrogen energy industry, the production process of the pole plate has progressed rapidly. The transformation of the traditional graphite industry and related manufacturing industries has provided great help for the production of fuel cell bipolar plates. I hope that fuel cells can enter thousands of households as soon as possible. For custom graphite materials or graphite bipolar plates please contact us for a quote.