What is the processing flow of 18650 lithium battery cells?

What is the processing flow of 18650 lithium battery cells?

Process flow of 18650 lithium battery cells.

18650 lithium battery is a commonly used lithium-ion battery in electronic products, often used as a battery cell in laptop batteries. The meaning of its model is as follows: for example, 18650 type, which refers to a cylindrical battery with a diameter of 18mm and a length of 65mm.

The processing process of 18650 lithium battery cells: coating

Firstly, starting from the coating process, large rolls of copper foil (yellow) and aluminum foil (silver) can be seen in this process. Aluminum foil is used to coat nickel cobalt manganese NCM ternary materials; On the contrary, copper foil is used to coat the negative electrode active material graphite; The white one is the diaphragm. The global lithium-ion battery separator is dominated by manufacturers such as Asahi, Celgard, SK, Toray, W-SCOP, and these foreign companies hold nearly 70% of the market share. And the market share of our country's separator companies is about 30%, and the independent localization of lithium-ion battery separators is constantly breaking through. The capacity of the battery cell is obtained based on the blending ratio and area of these formulas.

Process 2 of 18650 lithium battery cell processing: assembly
The sorted positive and negative electrodes will be fully automatically wrapped here, and the white material is the separator. 18650 lithium battery cells cannot function properly in this way. Electrolyte needs to be added as a medium to cause chemical reactions between the positive and negative electrodes, so that lithium ions can migrate between the positive and negative electrodes and produce charge ion output energy. Only then can lithium-ion batteries be charged and discharged. After being automatically wrapped, it rolls directly onto the assembly line and enters the next assembly step to be loaded into the steel shell.

The steel shell is formed by integral stamping with a thickness of less than 1mm, so high requirements are placed on the strength and quality of the steel. This 18650 lithium battery cell factory uses imported Korean steel materials.

Processing Process Three of 18650 Lithium Battery Cells: First Charging and Testing
After injecting electrolyte, 18650 lithium battery cells have not actually stored electricity, and the state of the positive and negative electrode surfaces has not reached stability at this time. They must be charged for the first time before they can be used normally, which is called chemical conversion. When charging for the first time, additional power needs to be added to form a protective film on the electrode surface, which is the secret of low self discharge in lithium-ion batteries. Meanwhile, the properties of the protective film also affect the performance and lifespan of the battery. Therefore, the chemical conversion process is very important. The transformation is completed using a separate container.