An Ultrastable Presodiated Titanium Disulfide Anode for Aqueous “Rocking‐Chair” Zinc Ion Battery

Rechargeable aqueous Zn‐based batteries are attractive candidates as energy storage technology, but the uncontrollable Zn dendrites, low stripping/plating coulombic efficiency, and inefficient utilization of Zn metal limit the battery reliability and energy density. Herein, for the first time, a novel presodiated TiS 2 (Na 0.14 TiS 2 ) is proposed and investigated as an intercalated anode for aqueous Zn‐ion batteries, showing a capacity of 140 mAh g −1 with a suitable potential of 0.3 V (vs Zn 2+ /Zn) at 0.05 A g −1 and superior cyclability of 77% retention over 5000 cycles at 0.5 A g −1 . The remarkable performance originates from the buffer phase formation of Na 0.14 TiS 2 after chemically presodiating TiS 2 , which not only improves the structural reversibility and stability but also enhances the diffusion coefficient and electronic conductivity, and lowers cation migration barrier, as evidenced by a series of experimental and theoretical studies. Moreover, an aqueous “rocking‐chair” Zn‐ion full battery is successfully demonstrated by this Na 0.14 TiS 2 anode and ZnMn 2 O 4 cathode, which delivers a capacity of 105 mAh g −1 (for anode) with an average voltage of 0.95 V at 0.05 A g −1 and preserves 74% retention after 100 cycles at 0.2 A g −1 , demonstrating the feasibility of Zn‐ion full batteries for energy storage applications.