A Hydrophobic Nanoconfined Interface for Anode-Free Aqueous Zinc Batteries.

Anode-free aqueous zinc batteries offer high-energy, low-cost storage but suffer from dendritic Zn deposition, water-induced side reactions, and active Zn loss on bare current collectors. Here, we develop a hydrophobic hydrogen titanate nanosheet-modified Cu current collector (HTO@Cu) as a multifunctional Zn host. Ti-O/Ti-OH sites enhance Zn2+ affinity and homogenize nucleation, the interconnected nanosheet network regulates Zn growth, and the hydrophobic surface suppresses interfacial water accumulation and parasitic reactions. Experiments and calculations confirm faster interfacial Zn2+ transfer, more uniform Zn deposition, and reduced water-related side reactions. Zn||HTO@Cu cells achieve 1200 cycles with an average Coulombic efficiency of 99.58%, while symmetric cells operate for over 2500 h. Strictly anode-free HTO@Cu||NVO cells (N/P = 0) cycle for over 40 cycles, and limited-Zn cells (N/P = 3) deliver 305 mAh g-1. The pouch cell reaches 178.5 Wh kg-1 based on cathode active material.