Lithium-ion battery pack manufacturing process
The production process from a simple battery cell to a lithium-ion battery pack is quite complex, involving multiple steps and is no simpler than the manufacturing process of a battery cell.
1. Loading materials
The battery cells are transported to a designated location, where a robotic arm automatically picks them up and feeds them into the module assembly line.
2. Plasma cleaning process to give the battery cells a bath
Each battery cell surface is cleaned. Ion cleaning is used here to ensure that contaminants do not adhere to the bottom of the cell during the process. Why use plasma cleaning technology? Because plasma cleaning is the most thorough stripping cleaning method. Its biggest advantage is that it produces no waste liquid after cleaning. Its greatest feature is that it can effectively handle metals, semiconductors, oxides, and most polymer materials, and can achieve overall, localized, and complex structure cleaning.
3. Assemble the battery cells and apply adhesive to them.
Before assembling the battery cells, an adhesive is applied to their surfaces. Besides securing them in place, this adhesive also serves to insulate and dissipate heat. High-precision adhesive application equipment, working in conjunction with robotic arms, allows for application along a set trajectory while simultaneously monitoring the application quality in real time, ensuring consistent application and further improving the consistency of each battery module.
4. Welding of the terminal plate and side plate for the battery cell.
Battery modules are mostly made of aluminum end plates and side plates welded together, and the lamination and welding of end plates and side plates are carried out by robots.
5. Assembly of wire harness isolation plate
After the welding monitoring system accurately locates the welding position, it binds the wire harness isolation plate material barcode to the MES production scheduling management system, generating a unique code for traceability. After coding, a robotic arm automatically loads the wire harness isolation plate into the module.
6. Complete the series and parallel laser welding of the batteries.
Automatic laser welding is used to connect the terminals and connecting pieces, enabling the batteries to be connected in series and parallel.
7. A crucial step before going offline: offline testing.
Before rolling off the production line, the modules undergo a full performance check, including module voltage/resistance, individual battery cell voltage, withstand voltage test, and insulation resistance test. The standardized module design principles allow for customization to match different vehicle models, and each module can be installed in the optimal space and predetermined location within the vehicle.
