New-Concept\nMetal-Based Artificial SEI Film of Polyimide\nAnode Material in Dual-Ion Batteries

Organic material polyimides (PI) are widely used in secondary\nbatteries\ndue to green safety, renewables, and structural designability. However,\nproblems such as low conductivity and structural damage of polyimide\nelectrode materials seriously limit its practical application. Herein,\nan innovative in situ modification method with CaCl<sub>2</sub> is\nused to construct pure Al metal-based artificial SEI film on the surface\nof PI to improve the electrochemical performance of organic dual-ion\nbatteries. Compared with the pure PI material, it has a noticeable\nimprovement in cycle performance. Importantly, characterization results\nof the physicochemical analysis show that the pure Al metal-based\nartificial SEI film formed in situ on the surface of the PI material\nplays a key role in isolating and improving the electrochemical performance\nof PI anode materials. The innovative approach offers an efficacious\nstrategy to construct pure metal-based artificial SEI films for the\npractical implementation of organic batteries.