Developing PI@PANI composites for aqueous zinc-ion batteries

Abstract

Polyimide electrode materials exhibit good electrochemical performance; however, their low conductivity limits their application. To address this issue, this study synthesized polyaniline-polyimide (PI@PANI) composites through chemical oxidative polymerization and solvothermal methods. The effects of the polyaniline ratio on the morphology, specific surface area, molecular weight, and electrochemical performance of the composites were investigated. The PI@PANI maintained its characteristic morphology, and when the polyaniline ratio was higher, the specific surface area of the composites increased along with the increase of high molecular weight polymers, while thermal stability slightly decreased. As an electrode material in zinc half-cells, Zn//PI@PANI (PI@PANI-2, NTCDA: ANI = 1:1) showed good cycling performance and rate capability. At a current density of 250 mA/g, after 400 cycles, the capacity retention reached as high as 90 %. Additionally, during full cell tests, the PI@PANI// MnO₂ full cell maintained a high capacity retention of 86 % after 500 cycles at a current density of 200 mA/g. These results indicate that the PI@PANI composites have significant application potential in the field of electrochemical energy storage, providing theoretical guidance and experimental evidence for further optimizing the composition and structure of the composites to enhance their electrochemical performance.