Low Resistance Flexible Current Collector for Lithium Secondary Battery

Flexible current collectors are fabricated through the placement of a thin copper layer onto various polymeric films such as poly (ethylene naphthalate) (PEN), poly(ethylene terephthalate) (PET), polyimide (PI), and poly(ether sulfone) (PES) by radio-frequency magnetron sputtering. Flexible current collectors with different Cu-sputtered thicknesses were examined as a current collector for lithium secondary batteries. As the thickness of the copper layer increased, the surface resistance of the flexible current collector decreased to the level of 1 Ω/Sq, which could make the unit cell based on the flexible current collector obtain comparable capacity as a copper metal foil current collector.