π – π Stacking‐Assisted Self‐Assembly Fabricates Highly Uniform PANI@RGO Cathodes Toward High‐Performance Aqueous Zinc‐Ion Batteries

ABSTRACT Polyaniline (PANI) is a promising cathode for aqueous zinc‐ion batteries (AZIBs) due to its fast redox kinetics and eco‐friendliness. However, the main challenges are still far from expectations owing to their morphological aggregation and low specific surface area. Herein, we report an N‐methyl‐2‐pyrrolidone (NMP)‐enabled solvent‐mediated self‐assembly strategy for preparing polyaniline/reduced graphene oxide (PANI@RGO) 3D porous composite gels with molecular‐level uniformity even at a very high PANI content (85%) through π – π stacking interactions (named as M‐PANI@RGO‐85%). The resulting M‐PANI@RGO‐85% composite exhibits a high specific surface area (189.55 m 2 g −1 ) and larger mesopores (36 nm) compared to water‐assisted counterparts (98.15 m 2 g −1 and 10 nm). As expected, based on the M‐PANI@RGO‐85% cathode, the fabricated M‐PANI@RGO//Zn AZIBs delivers remarkable specific capacity of 200 mAh g −1 (0.5 A g −1 ) and excellent rate performance (135 mAh g −1 at 10 A g −1 ). Notably, AZIBs exhibit excellent low‐temperature performance, maintaining a capacity of 148 mAh g −1 at 1 A g −1 at −20 °C. Additionally, the quasi‐solid‐state battery delivers a high energy density (198 Wh kg −1 ) and an extremely high power density (11.3 kW kg −1 ) are also achieved. These results demonstrate that π – π stacking‐assisted and solvent‐mediated self‐assembly method designs advanced organic electrodes.