Which Property of Graphite is Utilised in Making Electrodes?

graphite in making electrodesAs an important raw material for electrodes, graphite is indispensable in electrode manufacturing with its unique properties. Electrodes are widely used in a wide range of industries, from batteries and electrolysis in the electrochemical field to electric arc furnace steelmaking in the electrical field. Its performance directly affects the efficiency of the related process, product quality and energy consumption.

Graphite basic information

Physical appearance

Graphite is dark gray, metallic luster, soft texture, smooth touch, from a special crystal structure, can play a lubricating role in friction. Its density is about 2.09-2.23g /cm3, and the electrode made of it has good performance and light weight. It is suitable for equipment with weight requirements.

Chemical structure

Graphite is a typical layered structure. The carbon atoms in the layers form a hexagonal planar network with covalent bonds, and the layers are maintained by weak van der Waals forces. The interlayer covalent bonds give stability and strength to graphite. And the weak interlayer interaction enables it to form intercalation compounds, which expands the application field.

Characteristics of graphite used to make electrodes

Good electrical conductivity

One of the most outstanding characteristics of graphite is its good electrical conductivity. In its crystal structure, each carbon atom is bound to only three surrounding carbon atoms through covalent bonds. And the remaining one valence electron is able to move freely within the layer to form a free electron gas. These free electrons can move rapidly and directionally under the action of an applied electric field. Thus forming an electric current, which makes graphite have excellent electrical conductivity.

Compared with many metals, although its the electrical conductivity may be slightly inferior in numerical terms. In some specific application scenarios, such as in some electrical conductivity requirements are not extremely high. But there are strict restrictions on the chemical stability and cost of the material, its electrical conductivity has been able to meet the needs. And its cost advantages and chemical stability make it a more suitable choice. For example, in ordinary dry batteries, the graphite electrode plays a good conductive role. It conducts the electrons generated by the chemical reaction inside the battery to form a stable current output.

High melting point and high temperature resistance

It has a very high melting point, about 3652-3697°C. This makes it able to maintain stable physical and chemical properties in a high temperature environment. This high melting point and high temperature resistance play a crucial role in electrode manufacturing. In many industrial production processes, such as electric arc furnace steelmaking, electrolytic aluminum, etc., the electrodes need to work at extremely high temperatures. In the process of steelmaking, the arc generated between the electrode and the charge can produce a high temperature of thousands of degrees Celsius.

The graphite electrodes in such a high temperature environment, not only will not melt or deformation, but also can continue to work stably. It efficiently converts the electrical energy into heat energy, so as to achieve the heating and melting of the charge. If the melting point of the electrode material is low, it will melt rapidly at high temperatures. Resulting in electrode damage, which will not only affect production efficiency, but also increase production costs.

Chemical stability

Graphite shows good chemical stability in most chemical environments. It is not easy to chemically react with common acids, bases, salts and other chemicals. And it can maintain its own structure and performance stability in a variety of corrosive media. In the process of electrolysis, the electrode needs to be soaked in the electrolyte for a long time. If the chemical stability of the electrode material is not good, it will be corroded by the electrolyte. Resulting in a shortened life of the electrode, and it also affects the normal progress of the electrolytic process.

The graphite electrode, with its excellent chemical stability, can work stably in the electrolyte for a long time. To ensure the efficient and continuous electrolytic reaction. For example, in the chlor-alkali industry, you can use it to electrolyze salt water to prepare chlorine, hydrogen and sodium hydroxide. And in a strong alkaline electrolyte environment, it can operate stably, providing a reliable guarantee for industrial production.

Machinability

It has good machinability, which enables it to be processed into electrodes of various shapes and sizes. To meet the needs of different application scenarios. Due to the relatively soft texture of graphite, you can process it more easily by conventional machining methods. Such as cutting, drilling, grinding, etc. In the manufacture of electronic equipment, it is necessary to process graphite into ultra-thin, high-precision electrode sheets. And through precision cutting and grinding processes, precise processing of graphite can be achieved to meet the strict requirements of electronic equipment for electrode size and accuracy. Moreover, it is not easy to produce deformation and cracks during processing. It can ensure that the electrode after processing has good quality and performance.

Manufacturing process and application of graphite electrodes

Manufacturing process

Raw material pretreatment:

Select high-quality graphite raw materials such as petroleum coke. And calcination at high temperature to remove impurities, water and volatile components to improve purity and stability.

Mixed kneading molding:

Mix raw materials and binders such as coal pitch in proportion. After heating and stirring, mould it into a predetermined shape.

Roasting:

Roast the body at 1000-1300 °C to carbonize the binder and enhance the strength and density of the electrode.

Impregnation:

Soak the calcined electrode in asphalt and other impregnating agent, fill the pores under pressure and temperature to improve performance.

Graphitization:

Graphitize the impregnated electrode is at 2500-3000 °C, so that the carbon atoms are arranged more regularly and the performance is strengthened.

Machining:

Cutting and grinding of graphitized electrodes according to demand to achieve dimensional accuracy and surface quality requirements.

Application fields of electrodes made of graphite

Iron and steel industry:

In electric arc furnace steelmaking, graphite electrode is crucial. Using its high conductivity and high temperature resistance, input strong current to produce high temperature arc melting charge. With the improvement of steel industry requirements, it promotes the development of graphite electrode manufacturing technology.

Electrolytic aluminum industry:

You can use it as the anode in the electrolytic aluminum. And the conduction current is stable in the electrolyte with high temperature melting and strong corrosion. Due to the large scale and high energy consumption of electrolytic aluminum, the electrode conductivity, chemical stability and service life are required.

Electrochemical industry:

You can widely use it in chlor-alkali industry, electroplating, electrolytic refining and other fields. In chlor-alkali industry, graphite electrode anode achieves high efficiency electrolysis in strong alkaline electrolyte. During electroplating, it provides table current for the plating solution to ensure high quality electroplating.

Electronic field:

In lithium ion battery, you can use it as a negative electrode. Through good conductivity and chemical stability to achieve lithium ion embedding and removal, complete charge and discharge. In semiconductor manufacturing and other fields, you can use it for special processes such as EDM. To meet the needs of high-precision processing.

Conclusion

Graphite is an ideal electrode material because of its good electrical conductivity, high melting point, chemical stability and easy processing. The high performance electrode is made by complex technology and widely used. The development of science and technology promotes its technological innovation. And it is expected to help more fields in the future. And it is necessary to optimize the process to promote industrial development.