Reconfiguring Zn deposition dynamics via an epitaxial Zn2+ pathway in profiled viscose rayon for long-cyclability zinc-ion batteries

Abstract

Rechargeable aqueous zinc-ion batteries (AZIBs) are promising candidates for stationary energy storage owing to their intrinsic safety, environmental sustainability, and cost-effectiveness. However, their cycling stability is hampered by uncontrollable dendrite formation and hydrogen evolution reactions (HERs) at the Zn anode. Herein, we propose a cost-effective commercial viscose fabric derived from profiled viscose rayons as a versatile separator for reconfiguring the interface dynamics of Zn deposition, enabled by the surface grooves with abundant carboxyl groups on the profiled viscose rayons. Results show that carboxyl groups facilitate the desolvation of hydrated Zn²⁺ to suppress HERs, while the surface grooves provide epitaxial Zn²⁺ pathways for rapid horizontal transport of Zn²⁺ on the surface of the Zn anode, which promotes the transition of the Zn deposition manner from 2D to 3D diffusion and regulates the growth direction of Zn crystals from (101) to (002) to form uniform and dense Zn deposition on the anode. Consequently, AZIBs implementing the viscose fabric separator exhibit high battery performance, including an improved cycle life of over 4600 h at 1 mA cm⁻² and enhanced rate capability. This work highlights the significant potential of profiled viscose rayon in reconfiguring the interface dynamics of Zn deposition, providing guidance for the design of advanced separators in AZIBs.