Abstract

Polymer-based composite current collectors are considered promising alternatives to conventional Cu foils for lithium-ion batteries. However, insufficient adhesion between polymer substrates and metallic coatings limits their mechanical reliability and electrochemical stability. Herein, a synergistic interface engineering strategy integrating oxygen plasma pretreatment, polydopamine functionalization, Ag activation, and electroless Cu deposition is developed to fabricate PET-Cu composite current collectors. The synergistic functional interface promotes uniform Ag adsorption and regulates Cu nucleation and growth, resulting in a compact Cu coating with good conductivity and robust polymer-metal adhesion. The optimized PET-Cu current collector exhibits a low density of 1.32 mg & sdot;cm(-3), a low resistance of 29.3 m Omega, excellent adhesion, and stable electrical performance after 2000 bending cycles. Owing to the reduced current collector weight, the gravimetric capacity of full cells is improved by approximately 50% compared with Cu foil.

Keywords Plus：ENERGY

Published in MATERIALS LETTERS，Volume425；10.1016/j.matlet.2026.141548，DEC 15 2026