Prismatic battery cells gain more and more importance especially in automotive applications. With new cell chemistries like lithium iron phosphate (LFP) or sodium ion (SIB), which are enabling larger cell formats and additional trends like Cell2X-architectures without module level, the variety in cell formats increases rapidly. Besides “standardized” VDA formats with classic top terminal design for prismatic cells, there are several additional formats now in application or at least in development.
With these new designs, the mechanical cell components – cell can and cell cap – gain more and more importance. In some cases they have to handle additional functions like mechanical stiffness or advanced safety functions. Besides that, the cell housing is a main influence factor when it comes to volumetric and gravimetric energy density on pack level. The cell can together with the cell cap are lifetime determining in terms of tightness and mechanical stability. Furthermore, the cell cap is performance determining considering the electrical resistance from the cell inside to the outside.
Established manufacturing processes for the cell can like deep drawing do not work for all current designs of prismatic cell formats and there is poor availability in Europe. Tougher requirements regarding functionality and costs also require further investigations in this field. Therefore, new processes have to be established especially for the European battery industry.
In the scope of this contribution, current prismatic cell designs together with possible manufacturing processes are shown and compared. Furthermore, possible future developments to add functionalities or reduce costs of the cell housing, such as cell-integrated sensorics or integrated safety vents, are shown.