2.4 Cell Packaging

Cylindrical cells: The wound jelly roll with its welded tabs is inserted into a cylindrical metal can (typically steel or aluminium). The negative tab is often welded to the bottom of the can, while the positive tab is connected to the underside of the top cap assembly. Insulating gaskets and safety devices (like PTC and CID) are part of the can/cap system.  

Pouch cells : Packaging involves enclosing the assembled cell stack or jelly roll in its final housing. For pouch cells, the uncoated electrode flags are trimmed and welded to current collector tabs, typically via ultrasonic welding. The pouch foil is formed step-by-step into a bag using a press, into which the stack is inserted and sealed on three sides. This stage ensures mechanical protection and prepares the cell for electrolyte filling and final sealing. 

Prismatic cells: The electrode stack (or sometimes a flattened jelly roll) with welded tabs is inserted into a rigid prismatic can, typically made of aluminum or steel (or sometimes hard plastic). The positive and negative tabs are connected to the external terminals, which are often integrated into the cell lid. The lid is then welded (e.g., laser welded) or sealed onto the can.