Preparation of Polyaniline-coated Composite Aerogel of MnO2 and Reduced Graphene Oxide for High-performance Zinc-ion Battery

Aqueous zinc-ion batteries, especially Zn-MnO2 battery, have attracted intensive attention owing to their unique features of high capacity, environmental friendliness, and safety. However, the problem of Mn dissolution hinders the development of zinc-ion batteries with long-term usage and high-rate performance. In this work, a novel preparation method for the polyaniline (PANI)-coated composite aerogel of MnO2 and rGO (MnO2/rGO/PANI) electrode is reported. The obtained composite possesses high electrical conductivity, and also effectively suppresses the dissolution of Mn. The fabricated MnO2/rGO/PANI//Zn battery exhibits a high capacity of 241.1 mAh·g−1 at 0.1 A·g−1, and an excellent capacity retention of 82.7% after 600 charge/discharge cycles. In addition, the rapid diffusion coefficient of the MnO2/rGO/PANI electrode was further examined by galvanostatic intermittent titration technique. This work provides new insights into the development of high-performance Zn-MnO2 battery with a better understanding of its diffusion kinetics.