New-Concept Metal-Based Artificial SEI Film of Polyimide Anode Material in Dual-Ion Batteries

Organic material polyimides (PI) are widely used in secondary batteries due to green safety, renewables, and structural designability. However, problems such as low conductivity and structural damage of polyimide electrode materials seriously limit its practical application. Herein, an innovative in situ modification method with CaCl₂ is used to construct pure Al metal-based artificial SEI film on the surface of PI to improve the electrochemical performance of organic dual-ion batteries. Compared with the pure PI material, it has a noticeable improvement in cycle performance. Importantly, characterization results of the physicochemical analysis show that the pure Al metal-based artificial SEI film formed in situ on the surface of the PI material plays a key role in isolating and improving the electrochemical performance of PI anode materials. The innovative approach offers an efficacious strategy to construct pure metal-based artificial SEI films for the practical implementation of organic batteries.