Self-assembled multilayers direct a buffer interphase for long-life aqueous zinc-ion batteries

Abstract

There are extensive application prospects for rechargeable aqueous zinc-ion batteries (AZIBs) in stationary energy storage grids, but two major obstacles that remain are their interfacial instability and dendrite growth. Herein, we designed a specifically adsorbed self-assembled multilayer (SAM) to modify the structure of the electrical double layer (EDL). Based on the enrichment of zinc ions and the larger potential difference in the compact layer, the kinetics of the electrode reaction was accelerated. The molecular multilayer acted as a buffer layer that dynamically replenished the defects caused by the change in electrode morphology during the long-term cycling process. The designed SAM-Zn anode alleviated the concentration polarization and suppressed dendritic Zn growth. Consequently, the SAM-Zn anode with extremely reversible Zn plating/stripping endowed a cumulative plated capacity greater than 6.85 Ah cm⁻². Furthermore, the SAM-Zn||NH₄V₄O₁₀ pouch cell displayed an initial capacity of 211 mA h g⁻¹ with a capacity retention of 82.0% after 200 cycles at 2 A g⁻¹. This study extends the well-established method of SAMs into a platform for designing a function-oriented interphase that endows AZIBs with exceptional longevity.