Carbon and Graphite Anode Materials (Graphitized)

Carbon and Graphite Anode Materials (Graphitized)

Humans have never stopped exploring and using carbon. With the improvement of human living standard, the demand for energy is increasing rapidly, and countries are paying more and more attention to energy, especially new energy and sustainable energy. The solar industry has a strong demand for special graphite materials. The research, development and production of graphite materials for nuclear are becoming more and more urgent. The rise of electric vehicles has also greatly driven the development of carbon materials and high-performance additives for power batteries such as lithium ion batteries; High-performance electrodes, brushes, high-speed railway conductive sliders, carbon blocks and other traditional carbon materials are also continuing to develop and produce with the development of high-performance products.

The graphitization of carbon requires energy to be given to the carbon at high temperature so that the carbon with ordinary disordered structure can be transformed into ordered graphite with interlayer structure.

The degree of graphitization is mainly determined by the purity of carbon and the heating temperature of graphite chemical process, which is the main process for deepening the development of carbon materials and the use of cutting-edge technology. The melting point of graphite is 3850±50℃, the boiling point is 4250℃, and the carbon begins to change to graphite at 1700 degrees. The graphite electrode used for smelting and steelmaking, the general temperature is 2500 degrees. High purity graphite, such as lithium-ion battery anode material, needs to be around 3,000 degrees Celsius.This heating process is the graphitization sequence of the carbon industry.

The carbon production process includes calcination, medium crushing, screening, kneading, molding, roasting, impregnation, graphitization, processing and other processes. The graphitization process is the key process of carbon-graphite processing. The carbon material is heated to reach the graphitization temperature, usually between 2500 degrees and 3000 degrees. The heating process of heating the carbon to the graphitized state is generated by electric energy, and there are two processes, the external heating type large direct current method and the internal heating type internal string method.

Whether it is large-scale isotropic graphite, small-scale brushes, conductive sliders, or even a series of carbon-graphite products such as lithium-ion battery anode materials, graphitization is a key technical link in its industrial production process.

The graphitization process can be divided into external heat method and internal heat method according to the heating method, and can be divided into batch type and continuous type according to the operation mode. Since E.G. Acheson invented the graphitization furnace (called Acheson furnace) in 1895, the production of artificial graphite has a history of more than 100 years. With the development of industry, the structure of graphitization furnace has also been greatly developed. Acheson furnaces have DC and AC furnaces. In addition to the Acheson furnace, there are also internal string graphitization furnaces, continuous graphitization furnaces, etc.

The ash content of carbon products can be reduced by about 70% after the graphitization process, and the specific resistance is also much lower than that before roasting, which is more conducive to electrical conductivity, and the true specific gravity has increased by about 5%. In short, after the graphitization process, the oxidation resistance, thermal conductivity and chemical stability of carbon products have been improved.