Current collection through the ends of a spirally wound electrochemical cell

摘要

An electrochemical cell, including a jelly-roll type electrode stack (2), and a method for making such cell. The electrochemical cell includes folded electrode (4) portions (12) which form a plane (1) recessed from the end of the electrode stack (2). The folded electrode portions (12) are preferably formed by making pairs of slits (10) in the electrode end (6) and bending over the electrode portions between each pair of slits (10). The recessed plane (18) forms a large area to which a current collection tab (8) is subsequently connected. A coating may be applied to the folded portions (12) of the electrode (4) to further increase the contact area with the current collection tab by eliminating the slight variations in the recessed plane (18) which are due to the overlap of the folded electrode portions (12).