The battery system is a central element of the modular electric drive system (MEB), the new vehicle architecture that is consistently designed for electric drives. The largest German automobile manufacturer uses its broad experience in the development of all-electric and plug-in models. The battery systems are mainly manufactured at the Volkswagen components plant in Braunschweig. The Group Components division, which is responsible for the drive systems will become an independent division in January 2019. It is currently expanding this location in order to produce up to half a million battery systems annually.
Since 2017, Volkswagen has bundled the development of lithium-ion batteries in a Center of Excellence for battery cells in Salzgitter, which is responsible for all battery cells in the Volkswagen Group; in addition, a pilot line for battery cell production is currently being set up at the Salzgitter plant. The Group division also produces components for electric drives: The Kassel plant was specifically restructured for this purpose. Against this backdrop, the company is investing 1.3 billion euros in e-mobility in Braunschweig, Salzgitter and Kassel alone.
Aluminium battery housing with crash frame
The MEB batteries are constructed as follows: The lowest level is a solid collision protection. Above this is the aluminium battery housing with a crash frame, integrated battery cooling and a connection box for the high-voltage and low-voltage vehicle electrical systems (AC, DC and 12V). The newly developed MEB cell modules, which consist of individual battery cells, are inserted into the battery housing. The cell controllers (CMCe) - control units for monitoring the cells (voltage, currents and temperature) and cell balancing (ensuring equal load of the cells in daily operation) - are installed in the longitudinal member of the battery housing. The battery electronics (BMCe) are integrated in the rear part of the battery system as a further control unit. The cell modules are networked with each other via so-called cell module connectors; measuring lines communicate with the battery electronics. The battery housing is closed at the top with a debase. It can be easily removed for possible maintenance.
Since both the "pouch" and "prismatic" designs can be used as cell types, there is a high degree of flexibility in the cooperation with the cell suppliers. Volkswagen achieves the highest energy density via a maximum packing density within the cell modules. The energy density and thus also the energy content of the batteries will continue to rise in the coming years. A further breakthrough could also be achieved in the second half of the next decade with the use of solid cells.