Scalable and Sustainable Chitosan/Carbon Nanotubes Composite Protective Layer for Dendrite-Free and Long-Cycling Aqueous Zinc-Metal Batteries

• A sustainable protective layer for Zn anodes integrating carbon nanotubes (CNTs) and chitosan via a simple scraping process inhibits dendrite growth and side reactions. • Chitosan's polar functional groups enhance Zn2+ transport, and the even distribution of CNTs lowers local current density, enabling a uniform electric field to regulate Zn deposition. • Benefiting from the chitosan/CNTs protective layer, the Zn//Zn and Zn//V2O5 cells showcase significantly enhanced electrochemical performance, and technical economic analyses demonstrate their practical applications. • The reversibility of chitosan as a binder enables successful recovery of high-value CNTs, demonstrating sustainability and providing a novel design idea for highly efficient use of electrodes.