601848 polymer battery.Introduction to knowledge points of 18650 lithium battery production process

The theoretical lifespan of the 18650 lithium battery is 1,000 cycles of charging. Due to the large capacity per unit density, most of them are used in laptop batteries. In addition, because 18650 has very good stability at work, it is widely used in various major electronic fields: often used in high-end bright flashlights, portable Power supplies, wireless data transmitters, electric thermal clothing and shoes, portable instruments, portable lighting equipment, portable printers, industrial instruments, medical instruments, etc.

The theoretical lifespan of the 18650 lithium battery is 1,000 cycles of charging. Due to the large capacity per unit density, most of them are used in laptop batteries. In addition, because 18650 has very good stability at work, it is widely used in various major electronic fields: often used in high-end bright flashlights, portable Power supplies, wireless data transmitters, electric thermal clothing and shoes, portable instruments, portable lighting equipment, portable printers, industrial instruments, medical instruments, etc. So, what is the production process of 18650 lithium battery? Today Shenzhen will talk to you about this knowledge point, so that more people can have a deep understanding of 18650 lithium battery. (1) Bake for 12 hours at a constant temperature and a vacuum of -0.09MPa. The main purpose is to dry out the moisture in the battery core. (2) Liquid 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 battery design. The battery must be weighed before and after liquid injection. The weight difference is the liquid injection amount 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 any bad appearance such as yellow spots, black spots, defects, fires, etc., and try to pull the tabs to find batteries with weak spot welds such as fires, weak welding, or desoldering. (5) For sealing, first use a spot welding machine to spot weld the steel shell and cap of the battery, and then use a laser welding machine 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 2-5mm. There should be no wrinkles in the four corners of the pole piece, and the pole piece should not fall off. The tape should be applied diagonally, and the tape should be single-sided. It is too long, the double-sided tape is misaligned, the tape does not cover 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. Check the winding defects: the ion exchange membrane is uneven, that is, the positive and negative electrodes exceed the exchange membrane; the plate is high and the plate is low; the pole piece is not placed in place, the positive end of the outer ring does not hug the negative end, and the positive and negative plates of the inner ring are not in place. The tops of the exchange membranes are not overlapping and there is still a distance; the exchange membrane holds the tail of the negative electrode too tightly; the positive aluminum strip and the negative nickel strip are too long and short; the adhesive tape at the end of the battery core is defective; the battery core is not rolled in place: the distance between the positive and negative electrode ears is off. Wide or narrow; the exchange membrane is not flattened and wrinkled; the positive electrode is curled; the positive electrode piece is not curled or missing corners; the exchange membrane does not fully embrace the tail of the negative electrode piece; the inner and outer electrode pieces are misaligned.