402030 battery.18650 lithium battery production process and lithium battery assembly method

18650 lithium battery production process and lithium battery assembly method. Objectively speaking, the 18650 lithium battery production process is divided into three major sections, one is pole piece production, the other is battery cell production, and the third is lithium battery assembly. In the lithium battery production process, pole piece production is the foundation.

18650 lithium battery production process and lithium battery assembly method. Objectively speaking, the 18650 lithium battery production process is divided into three major sections, one is pole piece production, the other is battery cell production, and the third is lithium battery assembly. In the lithium battery production process, pole piece production is the foundation, battery core production is the core, and battery assembly is related to the quality of the finished lithium battery. The editor of this article will explain it in detail.

18650 lithium battery pack production process

(1)Baking

Bake for 12 hours at a constant temperature and vacuum of -0.09MPa. The main purpose is to dry out the moisture in the battery core.

(2)Injection

Inject the electrolyte into the vacuum-baked battery core in a glove box filled with Ar gas. The amount of liquid injected varies according to the design of the lithium battery pack. The battery must be weighed before and after the liquid injection. The weight difference is the amount of liquid injected. This is used to determine whether the injection volume is appropriate.

(3) Welding electrode tabs Weld the positive electrode tab (aluminum bar) and the negative electrode tab (nickel bar) to the scraper positions of the positive and negative electrode sheets using an ultrasonic welding machine. Pay attention to prevent welding deviation, welding misalignment, and false welding.

(4) Bottom welding. First put the insulating gasket into the steel case, then put the wound battery core into the steel case, and use a spot welder to weld the negative electrode lug to the bottom of the steel case. Check the outer surface of the bottom of the steel shell to find out the 18650 lithium battery packs with weak spot welding such as yellow spots, black spots, defects, and fire.

(5)Sealing

First use a spot welder to spot weld the steel shell and cap of the 18650 lithium battery pack, and then use a laser welder to continuously laser weld. Laser welding should ensure accurate positioning and clean parts to be welded. It is strictly forbidden to cause deformation or damage to the battery. Post-welding inspections should be carried out to repair welding of defective batteries with welding holes, explosions, etc.

(6) Winding

Place the ion exchange membrane flushly on the winding needle, and the front end extends out of the winding needle by 2-5mm. There should be no wrinkles in the four corners of the pole piece. The pole piece should not fall off, the tape should be applied at an angle, the single-sided tape is too long, and the double-sided tape should not be Defects such as the left and right misalignment of the tape, the tape not covering the solder joints, etc. The positive electrode material must hug the negative electrode material, the pole piece cannot be rolled sideways, and the front end of the pole piece must be inserted to the top.

18650 lithium battery assembly method

1. The 18650 lithium battery pack is arranged neatly, which will facilitate future maintenance. It is best to use the standard 18650 battery tray;

2. Good welding. The most popular welding method on the market is spot welding using a nickel welding machine. You can also use a soldering iron to make sure the solder joints are in good contact;

3. After welding, the circuits of each battery group must be sorted out clearly;

4. To ensure waterproofing and insulation, it is best to cut a piece of highland barley paper or use asbestos material;

5. The most important point is that the internal resistance of the battery before welding, the current voltage error should not exceed 0.05V! If possible, be sure to add a special protection plate for the 18650 lithium battery pack to prevent overshoot and over-discharge;

6. After welding, measure whether the voltage of each circuit is good;

7. After using the newly assembled lithium battery pack for a period of time, the voltage of the batteries should be tested in groups.

The above is the 18650 lithium battery production process and lithium battery assembly method. The 18650 lithium battery pack production process is quite complicated. After all, the safety performance of lithium-ion battery products is directly related to the life and health of consumers. Naturally, the performance of equipment in the production and manufacturing of lithium batteries , precision, stability and automation level have higher requirements.