Multifunctional Cellulose Nanocrystals Electrolyte Additive Enable Ultrahigh‐Rate and Dendrite‐Free Zn Anodes for Rechargeable Aqueous Zinc Batteries

Abstract The design of aqueous zinc (Zn) chemistry energy storage with high rate‐capability and long serving life is a great challenge due to its inhospitable coordination environment and dismal interfacial chemistry. To bridge this big gap, herein, we build a highly reversible aqueous Zn battery by taking advantages of the biomass‐derived cellulose nanocrystals (CNCs) electrolyte additive with unique physical and chemical characteristics simultaneously. The CNCs additive not only serves as fast ion carriers for enhancing Zn 2+ transport kinetics but regulates the coordination environment and interface chemistry to form dynamic and self‐repairing protective interphase, resulting in building ultra‐stable Zn anodes under extreme conditions. As a result, the engineered electrolyte system achieves a superior average coulombic efficiency of 97.27 % under 140 mA cm −2 , and steady charge–discharge for 982 h under 50 mA cm −2 , 50 mAh cm −2 , which proposes a universal pathway to challenge aqueous Zn chemistry in green, sustainable, and large‐scale applications.