How is
18650 lithium battery assembled? Today let's take a look at the super detailed assembly process of 18650 lithium batteries that are suitable for everyone to watch! For reference only, you can also try assembling it yourself.
We know that the outer shell of 18650 batteries is made of battery steel, and there is no commonly used battery spot welding machine. It is difficult to weld with an electric soldering iron. Of course, there are also powerful battery soldering fluxes available now, which can be easily used to weld 18650 batteries with regular soldering irons. But this type of strong soldering flux is corrosive and irritating, not only to the battery casing and positive electrode, but also to the soldering iron tip. So, how to solder 18650 cells and battery packs without a battery spot welder? Next, Energy Lithium Battery Manufacturer will teach you step by step how to use soldering iron to solder 18650 cells and assemble them into battery packs based on their practical experience.
1、 Moisture content of baked battery cells
Baking for 12 hours under temperature control and vacuum degree of -0.09MPa is crucial to better dry the moisture content of the battery cells.
2、 Inject liquid
After vacuum baking, the battery cells are filled with electrolyte in an Ar gas filled armrest box. The amount of electrolyte injected varies according to the design of the power lithium battery pack, and the battery must be weighed before, after, and after injection. The total weight difference is the amount of electrolyte injected, which is used to determine whether the amount of electrolyte injected is appropriate.
3、 Welding positive and negative electrode plates
Weld the positive electrode ear (aluminum strip) and negative electrode ear (nickel strip) separately to the scraping parts of the positive and negative electrode plates using an ultrasonic welding machine. Special attention should be paid to avoiding welding deviation, welding displacement, and empty welding.
4、 Bottom welding
Bottom welding. First, pour the insulation gasket into the battery steel shell, then pour the wound battery cells into the battery steel shell, and use a spot welding machine to weld the negative ear to the bottom of the battery steel shell. Check the outer surface layer of the bottom of the battery steel shell, pick out some yellow, black, defective, and burnt spots with poor appearance, and try to pull the electrode ears to pick out 18650 power lithium battery packs with weak spot welding such as burnt spots, empty welding, and desoldering.
5、 Sealing
First, use a spot welding machine to spot weld the battery steel shell and cap of the 18650 power lithium battery pack, and then use a laser welding machine to continuously laser weld them. Laser welding should ensure accurate positioning and cleanliness of the welded area. It is strictly prohibited to cause deformation or damage to the battery. After welding, inspection should be carried out to repair poor quality batteries such as welding holes and explosions.
6、 Winding up
Place the ion exchange membrane flat on the winding needle, with the front end extending 2-5mm from the winding needle. There should be no wrinkles at the four corners of the pole piece, and the pole piece should not have defects such as material falling off, tape being slanted, single-sided tape being too long, double-sided tape shifting left and right, or tape not covering the welding points. The positive electrode material must hold the negative electrode material, and the pole piece should not be rolled off center. The front end of the pole piece must be inserted to the top.
What should be done to assemble qualified lithium batteries?
1： We use high-quality and reliable lithium battery packs. Currently, the uniformity ratio of lithium batteries is relatively high, and the batteries are also good.
2： We need a high-quality lithium battery balanced protection board. Currently, the protection boards on the market are uneven, and there are also analog batteries that are difficult to distinguish from the appearance. Therefore, we need to choose a battery pack controlled by a good digital circuit.
3： Use a lithium battery charger instead of a regular lead-acid battery charger, and the charging voltage should match the balanced starting voltage of the protection board.
