Preparation and properties of PI@Cu composite films current collectors under silver catalysis for lithium-ion batteries

Abstract

As a high-performance polymer, polyimide (PI) exhibits excellent mechanical properties, thermal stability, electrical insulation, and chemical stability. However, the electrically insulating properties of PI limits its application in fields that require high electrical conductivity, so surface metallization is necessary. Conventional metallization methods make it challenging to achieve PI@Cu composite films with both good electrical conductivity and excellent mechanical properties. In this paper, the alkaline hydrolysis, silver ion activation, and pre-reduction methods were employed, followed by electroless plating, to successfully prepare a tightly bonded copper cladding layer on the PI film. The lowest resistivity of the prepared PI@Cu composite film is 2.53×10^–8 Ω·m, and the area density is as low as 1.22 mg/cm². This composite film is expected to be utilized as an anode collector for lithium-ion batteries instead of pure Cu foil. Furthermore, it effectively reduces the mass ratio of inactive substances in the electrode to enhance the energy density of the battery.