π-π Stacking-Assisted Self-Assembly Fabricates Highly Uniform PANI@RGO Cathodes Toward High-Performance Aqueous...

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 m² g^-1) and larger mesopores (36 nm) compared to water-assisted counterparts (98.15 m² 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.