Facet-selective molecular regulation of Zn metal anodes for durable aqueous zinc-ion batteries.

Abstract

Aqueous zinc-ion batteries (AZIBs) are attractive for grid-scale energy storage, yet Zn anodes suffer from dendrites, side reactions and restricted current windows. Herein, capecitabine (CAP) is employed as a electrolyte additive for Zn-deposition regulation and interfacial stabilization. The N/O-containing groups in CAP partially reconstruct the Zn²⁺ solvation and water hydrogen-bond network, reducing water activity. Meanwhile, facet-selective adsorption of CAP on Zn(100), forms an adsorption-mediated interfacial layer that suppresses parasitic reactions and promotes compact Zn(100)-textured deposition. Consequently, Zn‖Zn symmetric cells operate stably for over 7000 h at 1 mA cm^-2/1 mAh cm^-2. Moreover, Zn‖ZVO full cells retain 82.45% capacity after 5500 cycles at 5 A g^-1. CAP-mediated electrolyte-structure regulation and Zn(100)-selective interfacial modulation provide a molecular strategy for highly reversible Zn metal anodes.