The coating process uses a coater (a coating machine) to coat aluminum and copper foils with the cathode and anode slurry layers, respectively. It is an important step that determines many cell design parameters like uniform performance and longer battery life.
For more information, please visit HUIYAO.
In order to prevent damage to aluminum and copper current collectors (or foils) when coating the electrodes, controlling the roll-to-roll machine and coating electrodes evenly and uniformly are critical.
After coating, these wet layers still need to be dried thoroughly before being ready for the next phase. This process of drying by heating or vacuum takes up to 48% of the entire battery manufacturing process.
Winding is to separate the positive and negative electrode sheets with a separator and roll them into a roll core (the cell of a lithium-ion battery) of a specific size. It is mainly used for the production of square and round lithium batteries.
Winding machines can be subdivided into square winding machines and cylindrical winding machines, which are used for the production of square and cylindrical lithium batteries respectively. Compared with cylindrical winding, the square winding process has higher requirements for tension control, so the square winding machine technology is more difficult.
ALF shaping is punching aluminum plastic film into a shell of a specific size to facilitate the packaging of the battery cell.
Put the rolled cell into the punched aluminum-plastic shell film, and seal the aluminum-plastic film into a bag with side openings.
During the production process of battery cells, a certain amount of moisture will be introduced. If the moisture is not controlled within the standard in time, it will seriously affect the performance and safety of the battery.
If you are looking for more details, kindly visit China li ion battery pack assembly.
Generally, an automatic vacuum oven is used for baking. The cells to be baked are placed neatly, the desiccant is placed in the oven, the parameters are set, and the temperature is raised to 85°C (taking lithium iron phosphate cells as an example). Several vacuum drying cycles are required.
Baking process: heating, vacuuming, nitrogen replacement. These three steps act as a cycle. Bake for about 6 to 10 cycles. In this way, the moisture content of the electrode can be controlled to within 150ppm. After completion, cool the battery temperature to normal temperature and fill it with liquid.
Conduct a moisture test on the baked battery cell. Only after it meets the previous baking standards can you proceed to the next step: injecting electrolytes.
Liquid injection is to inject a certain amount of electrolyte into the battery cell to wet the electrode and separators. The liquid injection process includes entering the warehouse, filling the liquid, vacuuming, and sealing once.
Quickly put the baked cells into the vacuum glove box, weigh them, record the weight, and put them on the liquid injection sleeve. Add the designed weight of the electrolyte into the cup and put it into a vacuum box to evacuate to accelerate the penetration of the electrolyte into the electrode.
After several cycles, take out the battery cell and weigh it to calculate whether the liquid injection amount meets the design value. Less need for rehydration. If it exceeds the limit, the excess needs to be discarded. until the design requirements are met.
After the liquid injection is completed, it needs to be left at 45°C for 24 hours before it can be transferred to the formation process.
Want more information on private label prismatic battery pack assembly? Feel free to contact us.