In a battery cell a current collector can be found as the metallic backing sheet of the anode and the cathode. These are normally copper or aluminium, depending on the chemistry and on whether it is the anode or the cathode.
Typically the current collectors are 5 to 25µm in thickness.
Perforated Current Collectors
Using laser-perforated copper foil allows the silicon-carbon composite to form inter-penetrating “stitches” through the current collector, tightly holding the electrode together and preventing delamination caused by expansion forces.
See also: Options that Solve the Expansion of Silicon Anodes, 3D Electrodes