This process is the last process. The stirred slurry is evenly sprinkled on the bottom of the 4000 meters of copper foil at a speed of 80 meters per minute. The copper foil before coating is only 6 microns thick, which can be described as thin silkworm wings.
Coating is essential to ensure that the thickness and components of the electrodes are consistent, otherwise it will affect the consistency of the battery. The coating must also ensure that no particles, debris, and dust are mixed into the pole. Otherwise, the battery will discharge too quickly and even cause safety hazards.
The negative film on the copper foil is pressed up and down and then cut cold pressing and pre-cutting
In the rolling workshop, the plate with positive and negative data is connected to the roll for rolling, so that the coated data is more compact, the energy density is improved, and the thickness consistency is ensured. On the other hand, dust and humidity are further controlled.
According to the size of the battery to be produced, cut the cold-pressed electrode sheet to fully control the appearance of burrs (the burrs can only be seen clearly under a microscope). The purpose of this is to prevent the burr from penetrating the gap, causing serious safety hazards.
Cut out the small ears of the positive and negative electrodes on the battery pole, die-cut and split
The tab die-cutting process uses a die-cutting mechanism to make the tabs into a conductive battery. We understand that a battery is divided into a positive electrode and a negative electrode. The tabs are separated from the metal conductor by the battery. The positive and negative tabs of the battery are the contact points when the battery is charged and discharged.
The next step is to cut the battery with a cutting knife.
Complete the winding process of the prototype battery
Here, the positive electrode, negative electrode, and separator of the battery are combined in a winding manner to form a bare battery. Advanced CCD visual inspection equipment can complete active detection and active correction to ensure a good position of the battery pole.
CATL Ningde battery production workshop is one of the most active battery production workshops in the world with CCD visual inspection equipment.
Remove moisture and inject electrolyte for baking and injection
Water is the enemy of the battery system. The baking process of the battery is to make the inside of the battery meet the water standard, ensuring that the battery has good functions throughout its life cycle.
Liquid injection is to inject electrolyte into cells. Electrolyte is like blood flowing in cells, and the exchange of energy is the exchange of charged ions. These charged ions are transported from the electrolyte to another electrode, where they are charged and discharged. The injection volume of electrolyte is the key in the key. If the injection volume of electrolyte is too large, it will cause the battery to heat up or even directly fail. If the injection volume is too small, it will affect the cycle of the battery.