Dynamic Noncovalent Interactions: The Role of Supramolecular Chemistry in Stabilizing Aqueous Zinc-Ion Batteries

ConspectusAqueous zinc-ion batteries (ZIBs) are increasingly recognized as leading candidates for grid-scale energy storage owing to their intrinsic safety, material abundance, and low cost. However, their practical deployment is fundamentally constrained by a self-amplifying failure cycle at the zinc anode, wherein inhomogeneous Zn²⁺ flux induces dendritic growth, which exacerbates the hydrogen evolution reaction (HER) and promotes the formation of insulating passivation layers (e.g., Zn₄SO₄(OH)₆·xH₂O). Conventional mitigation strategies, such as structural engineering of the anode, surface coatings, or electrolyte optimization, are largely static and lack the dynamic adaptability required to stabilize the evolving electrode-electrolyte interface over extended cycling. In this context, supramolecular chemistry, governed by reversible noncovalent interactions, molecular recognition, and self-assembly, offers a transformative and dynamic platform to address the root causes of ZIB instability. This Account systematically elucidates the core mechanisms by which supramolecular systems operate: (1) host-guest recognition, wherein macrocyclic hosts (e.g., cyclodextrins, cucurbiturils, crown ethers) selectively bind Zn²⁺ or anions to reconfigure solvation structures and direct uniform ion transport; (2) interface stabilization via self-assembled supramolecular layers that create water-deficient, flexible artificial SEI layers to suppress parasitic reactions; and (3) dynamic hydrogen-bond networks that enable real-time adaptation, self-repair, and mechanical buffering against volume fluctuations. We highlight key contributions from our group and others across diverse application domains, including host-guest electrolyte additives, supramolecular gel electrolytes, and interfacial engineering, demonstrating precise control over Zn²⁺ deposition behavior (e.g., epitaxial (002) growth), effective HER suppression, and enhanced performance under extreme conditions such as low temperature. Through integration of advanced in situ characterization and multiscale simulations, we establish structure-property relationships that inform the rational design of next-generation supramolecular systems. Finally, we outline critical challenges and future directions, including elucidation of noncovalent interaction dynamics under operando conditions, development of multifunctional hosts with tailored selectivity, scalable and sustainable synthesis, and full-cell validation (e.g., suppression of cathode dissolution). This Account underscores that supramolecular chemistry, through its dynamic and adaptive nature, overcomes the inherent limitations of conventional static approaches and paves the way toward durable, high-performance ZIBs for sustainable energy storage.