What is lithium battery roller press machine

1, the basic overview of lithium battery roller press machine

Lithium battery roller press machine, from the name can be roughly understood its main functions and structural characteristics. It is a kind of mechanical equipment specially used to deal with lithium battery electrode sheet, mainly composed of two relatively rotating rolls, transmission system, pressure regulation system, roll gap regulation system and control system. The working principle is that the coated electrode sheet is placed between two rolls, and the roll is driven by the drive system to rotate, and under the pressure exerted by the pressure regulating system, the electrode sheet is gradually compacted and passes through the roll gap, so as to achieve the set thickness and density requirements.

In the preparation of lithium battery electrode sheet, the role of roller press is very important. The electrode sheet is usually composed of active substances, conductive agents, binders, etc. After the coating process, it is necessary to roll through the roller press to improve the physical and chemical properties of the electrode sheet, and then improve the overall performance of the lithium battery.

2, lithium battery roller press machine in the electrode thickness control of the role

(1) Precise control of electrode thickness

The lithium battery roller press machine can accurately control the thickness of the electrode sheet, which has a direct impact on the performance of the lithium battery. In the design and manufacturing process of lithium batteries, the thickness of the electrode sheet needs to be strictly controlled within a certain tolerance range.

(2) Improve battery energy density

Appropriate electrode thickness control is of great significance to improve the energy density of lithium battery. In a limited battery volume, the thickness of the electrode sheet is directly related to the content of active substances. By compacting the electrode sheet to the appropriate thickness through a roller press, more active substances can be accommodated in the same volume of electrode sheets, thereby increasing the energy storage capacity of the battery.

3, the influence of lithium battery roller press machine on the compaction density of electrode sheet

(1) Enhance the compaction density of the electrode sheet

Another important role of the lithium battery roller press is to improve the compaction density of the electrode sheet. In the rolling process, the pressure applied by the roller press makes the contact between the active substance, the conductive agent and the binder in the electrode sheet tighter, reducing the gap between the materials, and thereby increasing the compaction density of the electrode sheet. The higher compaction density is helpful to improve the electron conduction and ion diffusion properties of the electrode. When the compaction density of the electrode plate increases, the transmission path of electrons in the electrode plate is smoother, the resistance is reduced, and the charging and discharging efficiency is improved. At the same time, the diffusion rate of lithium ions in the electrode sheet will also be accelerated, which is conducive to improving the charge and discharge ratio performance of the battery.

(2) Improve battery cycle life

Good compaction density also has a positive impact on the cycle life of lithium batteries. In the charge and discharge cycle of lithium batteries, the electrode sheet will undergo repeated volume expansion and contraction. If the compaction density of the electrode sheet is uneven or too low, it is easy to cause problems such as powder and fall off of the electrode material during the cycle, so that the performance of the battery gradually declines. By compacting the electrode sheet evenly, the electrode material forms a stable structure, which can better withstand the volume change in the charge and discharge process, reduce the loss of active substances, and thus extend the cycle life of the lithium battery. In the application scenarios such as energy storage power stations with high battery cycle life requirements, the role of roller presses in improving the compaction density of electrode sheets is particularly important.

4,The role of lithium battery roller press in improving the electronic conductivity of electrode sheet

(1) Optimize the electron conduction path

During the rolling process, the conductive agent in the electrode sheet can be better distributed among the active substances and the electron conduction path can be optimized. The conductive agent plays an important role in connecting the active substance and collecting the fluid in the electrode, and the uniformity of its distribution and the closeness of contact with the active substance directly affect the electron conductivity. The compaction effect of the roller press can promote the conductive agent and the active substance to form a closer contact network, reduce the contact resistance of electron conduction, and improve the transmission efficiency of electrons in the electrode sheet. This is of key significance for improving the charge and discharge performance of lithium batteries, especially the high rate charge and discharge performance, which can meet the needs of modern electronic devices and electric vehicles for fast charging and high power discharge.

(2) Improve the overall performance of the battery

Good electron conductivity can not only improve the charge and discharge efficiency of lithium batteries, but also have a positive impact on other performance indicators of batteries. For example, in a low temperature environment, the improvement of electronic conductivity can reduce the increase in the internal resistance of the battery and reduce the attenuation degree of the battery performance, so that the lithium battery can still maintain good working performance in a low temperature environment.

5, lithium battery roller press to improve the mechanical strength of the electrode

(1) Enhance the tensile and bending resistance of the electrode sheet

In the production, assembly and use of lithium batteries, the electrode needs to withstand a certain mechanical stress. By compacting the electrode sheet, the lithium battery roller can significantly enhance the mechanical strength of the electrode sheet, including the resistance to stretching and bending. After rolling, the electrode sheet structure is more compact, and the binding force between the materials is stronger, which can effectively prevent the fracture and damage in the process of processing and use.

(2) Ensure the safety of battery production and use

The mechanical strength of the electrode sheet also has an important impact on the safety performance of lithium batteries. If the electrode sheet is damaged during use because of insufficient mechanical strength, it may lead to serious problems such as internal short circuit, resulting in safety accidents such as battery thermal loss and even fire and explosion. By improving the mechanical strength of the electrode sheet, the lithium battery roller reduces this safety risk from the source, and provides a reliable guarantee for the production and use of lithium batteries. In the field of high battery safety requirements such as aerospace and military, the role of the roller press in improving the mechanical strength of the electrode can not be ignored.

6,Conclusion

As one of the core equipment in the manufacturing process of lithium battery, the roller press plays an irreplaceable role in electrode thickness control, compaction density improvement, electronic conductivity optimization, mechanical strength improvement and so on. Through the precise rolling process, it can significantly improve the energy density, charge and discharge efficiency, cycle life and safety and other performance indicators of lithium batteries, laying a solid foundation for the wide application of lithium batteries in various fields.