Topological Frustration of Ångström-Confined Water for Stable Aqueous Zinc-Ion Batteries.

Abstract

Despite extensive efforts to regulate water activity in hydrogel electrolytes for aqueous zinc-ion batteries (AZIBs), current strategies are insufficient to impose spatial constraints on water molecules and prevent the self-assembly of bulk water networks. Herein, we report a quasi-solid hybrid electrolyte (HM) by integrating polyacrylamide with a rigid inorganic montmorillonite (MMT) framework that imposes strong ångström confinement on interlayer water molecules. Such spatial confinement restricts the volume required to assemble a bulk three-dimensional tetrahedral hydrogen-bond network. Concurrently, polar Si-O bonds on the MMT surface chemically anchor water molecules in a one-hydrogen-down configuration, inducing symmetry breaking and topological frustration. Consequently, Grotthuss-type proton transport and water autoionization are suppressed. This molecular-level regulation mitigates water-induced parasitic reactions and byproduct accumulation, ensuring a reversible Zn/electrolyte interface. As a result, the assembled Zn||NH₄V₄O₁₀ full cell achieves stable cycling for over 800 cycles at 1 A g^-1. By shifting the electrolyte design toward ångström topological engineering, this work establishes a promising paradigm for suppressing water-induced parasitic reactions in high-performance AZIBs.