Synergistic Biomass Electrolyte via Mechanochemistry Enables Ultralong-Life Dendrite-Free Zinc Anodes

Zinc metal, a promising anode for aqueous zinc-ion batteries (AZIBs) due to its high capacity, low cost, and safety, suffers from irreversibility caused by side reactions and dendrite growth. While electrolyte additives offer a solution, designing low-cost, green additives remains challenging. Herein, we introduce a novel, multifunctional electrolyte (CSZE) prepared via a solvent-free ball milling mechanochemical process using microcrystalline cellulose (MCC), succinic anhydride (SAD), and ZnSO₄ (ZS). This one-pot solid-phase synthesis leverages ZS as both catalyst and electrolyte solute. The resulting cellulose succinate ester (CSAE) and succinic acid (SA) exhibit a synergistic effect, promoting close Zn²⁺ binding and uniform deposition, surpassing the performance of either component alone. Carboxyl and hydroxyl groups within CSAE/SA facilitate strong adsorption on the Zn anode, effectively shielding it from dendrite formation and corrosion. Consequently, the Zn anode achieves exceptional reversibility for 3666 h at 1 mA cm⁻²/1 mAh cm⁻². Paired with a MnO₂ cathode, the full cell retains 79.75% capacity after 4000 cycles at 5 A g⁻¹. Life-cycle assessment further demonstrates a 22.64% reduction in global warming potential versus conventional electrolytes. This work presents a sustainable strategy utilizing abundant lignocellulosic biomass for high-performance, reversible AZIBs.