1. Homogenization method
Slurry dispersion is a step in the production of lithium ion batteries.
The tank body, mixing bar and conveying pipe of homogenizing equipment are all made of metal materials, so there is a danger of introducing metal impurities, and the equipment will be worn if it runs for a long time. This work requires lithium battery manufacturers to clean the tank before homogenization, maintain the mixing equipment regularly, clean the pipeline in time, track the performance of homogenized batteries, and establish their own internal cleaning standards to produce qualified lithium batteries. It should also be noted that many companies cannot guarantee that one homogenizing line can only produce one type of battery, so the pipeline should be cleaned during the conversion of raw materials to prevent the mixed use of different batches of powder, resulting in unnecessary loss of performance and safety. Of course, the frequency and standard of cleaning need to be explored for a long time, and different equipment and material requirements are also different, so Lao Li won't say much here.
2. Paint
For the coating, it is important to clean each roller and repair it after wear to prevent the introduction of impurities. And with the popularization of double-sided gluing equipment, the gluing speed is getting faster and faster, and the length of the equipment is getting longer and longer. Therefore, timely detection of problems will greatly improve the safety of batteries.
3. Mobility
In fact, like the coating, the compactness of the material increases with the increase of energy density, so the cleaning and maintenance of the roller is a control means to prevent impurities from entering.
Quartering
For lithium ion battery manufacturers with a high degree of automation, the width of positive and negative electrodes coated with uniform slurry is very wide, so it is generally necessary to perform slitting. Generally, the slitting is wide with metal slitting knife and narrow for subsequent processes. It adopts a key index directly related to safety - burr. Excessive burr will directly cause battery short circuit. Therefore, the importance of controlling the parameters and burrs of each lithium ion battery manufacturer is self-evident. How to control? The equipment has high requirements for cutting technology and cross cutting burrs, and the maintenance of the cutting knife is the key. Every enterprise has its own regulatory standards and sampling regulations, so I won't say much here.
5. Laser cutting
The important purpose of this process is to cut the tab from the foil with a laser. Like slitting, the key control point is the control level of burrs after laser cutting. Whether dust and impurities can be removed in time after laser cutting depends on the automation level of equipment and a series of advanced online monitoring systems.
6、 Adhesion/lamination
As for binding, the alignment of binding, the extent to which the cathode covers the anode, and the extent to which the anode, cathode and diaphragm burr after binding are the keys to control.