An electron/ion pathway reconstruction strategy enabling fast aqueous Zn2+ storage

Aqueous Zn ion batteries are considered ideal alternatives for scalable energy storage due to their reliable safety, affordable cost, and sustainability. However, the further development of ZIBs is limited by the design of the cathode, especially with kinetics coupling of electron transfer and ion diffusion. Here, we develop an electron/ion pathway reconstruction strategy to enhance the kinetics of Zn storage by designing a composite of a reduced graphene oxide wrapped polyaniline/vanadium oxide superlattices. The superlattice structure of V-O layers stacked with polyaniline enables rapid Zn2+ diffusion due to the enlarged interlayer spacing and redistributed electron structure. Meanwhile, the lamellar superlattices wrapped with rGO optimizes electron transfer pathway and enhances mechanical stability. Therefore, the synergistic optimization between ion migration inside superlattices and charge transport in bulk materials achieves double acceleration for Zn2+ storage kinetics, showing superior rate capability (≥100 mAh g-1 at 20 A g−1) and cycling durability. Moreover, the electrochemical mechanism investigation shows that the as-obtained composite cathode presents highly reversible Zn diffusion behavior and good structural stability through a series of in-situ spectroscopic characterizations. It is hoped that this electron/ion pathway reconstruction strategy can provide a new perspective for the development of high-performance cathodes for aqueous batteries.