What is actually behind a "battery" in an electric vehicle? We give a very short overview of the most important components: cell, module and pack.
Batteries for electromobility are produced in different manufacturing steps. Comprehensive quality tests are carried out at all levels of the production steps. The individual steps usually take place in different plants.
The first production step is the largely automated manufacture of battery cells, which in simplified form consist of anodes, cathodes, separators, and electrolyte. Chemicals are only processed during cell production. Battery cells are currently manufactured either as pouch cells, round cells, or prismatic cells.
Modules consist of several cells. Depending on the cell technology used, sufficient space must be provided for the expansion of the cells (pouch) and the cooling of the cells must be ensured. The cells must be mounted in a frame and interconnected. Before assembly, they are checked for quality, cleaned or activated, and then mounted in the frames or glued together. The modules are then insulated with heat-dissipating foils, which also interrupt the flow of current to neighboring modules and thus act as fire protection. The boards of the battery management system are then connected and mounted. Before several modules are assembled into a pack, cables are attached, and the module is sealed via cover plates.
Several modules are assembled in a tub to form a battery pack. Before the modules are assembled, cooling plates for operation and a heater for winter use are mounted in the tub. The cell modules are fixed in the frame and interconnected. At the pack level, the modules are controlled by a central high-voltage module, the battery management system master, and the central cooling module. Only suitably qualified personnel are permitted to assemble the high-voltage connection. The pack must then be prepared and sealed for installation in the vehicle. Before mounting, the desired uniform charge level must be established and the respective current battery management software must be loaded.