Fluorinated Aromatic Anode‐electrolyte Interface for Highly Reversible Zinc Anode

Abstract The issues of dendrite formation and side reactions at the zinc anode–electrolyte interface are the primary factors limiting the reversibility and stability of aqueous zinc‐ion batteries (AZIBs). Herein, the functionalities of fluorinated aromatic additive on zinc anode–electrolyte interface are investigated by comparing a series of organics with N‐, phenyl‐, and F‐ groups individually or jointly. An additive, 3‐(trifluoromethyl)‐phenyltrimethyl‐ammonium bromide (TFPM), featuring the hydrophobic groups from benzene ring and fluorine together, effectively regulates zinc ion deposition to prevent dendrite formation. It also isolates high‐activity water during the desolvation process and forms a robust solid electrolyte interphase (SEI) layer to suppress interfacial parasitic reactions. As a result, Zn//Zn symmetric batteries with TFPM additive exhibit an ultralong cycling lifetime over 5900 h (over 8 months) at 0.5 mA cm ⁻² , and improved Coulombic efficiency (CE) of 99.93% over 4000 h at 1 mA cm ⁻² than bare ZnSO ₄ electrolyte in Zn//Cu symmetric batteries. Paring with Mn ²⁺ preintercalated V ₂ O ₅ · n H ₂ O cathode (MnVO), the full battery delivers a high capacity of 263 mAh g ⁻¹ at 8 A g ⁻¹ with a retention of 94.9% over 6000 cycles. This work provides a promising interface‐engineering strategy from the functional group design of additives for high‐performance AZIBs.