Graphite Bipolar Plate

Graphite bipolar plates are produced using high-quality graphite raw materials, including natural graphite and expanded graphite, through precision machining. These makes our products having good electrical and thermal conductivity. They can effectively improve the efficiency of the battery. While strong corrosion resistance, to ensure long-term stable operation.

Properties of graphite bipolar plates

High electrical conductivity: Graphite has good electrical conductivity, which can ensure the efficient operation of fuel cells.

Corrosion resistance: Strong graphite materials have excellent corrosion resistance to a variety of chemical. They can work stably in the corrosive environment of fuel cells for a long time.

Good thermal conductivity: The thermal conductivity of graphite bipolar plate can reach 2.17×10^6 W/(cm·K) at room temperature. And it still maintains good thermal conductivity at high temperatures. Its melting point is as high as 3850°C and its boiling point is 4250°C, which makes it able to work stably in high temperature environment without deformation or damage.

Small deflation rate and permeability: As fuel cells with graphite bipolar can convert hydrogen and oxygen into electricity, it may produce water during reaction. The feature of graphite can avoid the leakage of gas and water effectively . This ensures the normal operation of the fuel cell.

Graphite Bipolar Plate Manufacturing Process

Raw material selection and pretreatment: We use high purity graphite powder for drying treatment. The particle size is normally within10~50 microns.

Forming and preliminary curing: Press the mixture into the mold, initial curing after release.

Impregnation and carbonization: The initial cured bipolar plate is impregnated, usually using synthetic resin or phenolic resin to fill the graphite surface and internal pores. The impregnation generally takes 24 hours or more to ensure that the resin can fully penetrate.

Then carbonize the impregnated bipolar plate at high temperature. This aims to convert the resin into a carbonaceous material, further enhancing the strength and conductivity of the bipolar plate.

Slicing and polishing: Slice the graphite bipolar plates to appropriate thickness. And polish the surface until smooth.

Heat treatment: Heat the cured bipolar plate between 500 and 1000 degrees Celsius. This step can further improve the crystallinity and electrical conductivity of graphite. Then cool down plates slowly to room temperature, this can prevent graphite bipolar plates from cracking because of thermal stress.

Assembly and sealing: Assemble the bipolar plates according to the requirements of the battery stack to form a complete battery structure. Use a sealant or gasket to seal the battery stack to prevent leakage and corrosion.

In the entire production process, we strictly control the process parameters and quality standards of each link to ensure that the performance and quality of the final product meet the requirements. We also carry out regular maintenance and cleaning of the production equipment and environment to maintain its normal operation and good production environment.

Applications

The graphite bipolar plate is mainly used in fuel cells. Normal batteries that release mercury, lead and acid and alkali after use, these are harmful to environment. However, fuel cell with graphite bipolar plates can use hydrogen and oxygen to generate electricity, producing electricity and producing water vapor. Therefore, the battery with graphite bipolar plate can convert clean energy in a more efficient and environmental-friendly way. In addition, it can also be used in fixed auxiliary power supplies, and engines for electric vehicles to provide electricity.