The realizing of high‐performance rechargeable aqueous zinc‐ion batteries (ZIBs) with high energy density and long cycling life is promising but still challenging due to the lack of suitable layered cathode materials. The work reports the excellent zinc‐ion storage performance as‐observed in few‐layered ultrathin VSe2 nanosheets with a two‐step Zn2+ intercalation/de‐intercalation mechanism verified by ex situ X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS) characterizations. The VSe2 nanosheets exhibit a discharge plateau at 1.0–0.7 V, a specific capacity of 131.8 mAh g−1 (at 0.1 A g−1), and a high energy density of 107.3 Wh kg−1 (at a power density of 81.2 W kg−1). More importantly, outstanding cycle stability (capacity retention of 80.8% after 500 cycles) without any activation process is achieved. Such a prominent cyclic stability should be attributed to its fast Zn2+ diffusion kinetics (DZn2+ ≈ 10−8 cm−2 s−1) and robust structural/crystalline stability. Density functional theory (DFT) calculation further reveals a strong metallic characteristic and optimal zinc‐ion diffusion pathway with a hopping energy barrier of 0.91 eV. The present finding implies that 2D ultrathin VSe2 is a very promising cathode material in ZIBs with remarkable battery performance superior to other layered transitional metal dichalcogenides.

2D materials with atomically precise thickness and tunable chemical composition hold promise for potential applications in nanoenergy. Herein, a bilayer-structured VOPO 4 ⋅2H 2 O (bilayer-VOP) nanosheet is developed with high-concentration oxygen vacancies ([Vo˙˙]) via a facile liquid-exfoliation strategy. Galvanostatic intermittent titration technique study indicates a 6 orders of magnitude higher zinc-ion coefficient in bilayer-VOP nanosheets (4.6 × 10 −7 cm −2 s −1 ) compared to the bulk counterpart. Assistant density functional theory (DFT) simulation indicates a remarkably enhanced electron conductivity with a reduced bandgap of ≈0.2 eV (bulk sample: 1.5 eV) along with an ultralow diffusion barrier of ≈0.08 eV (bulk sample: 0.13 eV) in bilayer-VOP nanosheets, thus leading to superior diffusion kinetics and electrochemical performance. Mott-Schottky (impedance potential) measurement also demonstrates a great increase in electronic conductivity with ≈57-fold increased carrier concentration owing to its high concentration [Vo˙˙]. Benefited by these unique features, the rechargeable zinc-ion battery composed of bilayer-VOP nanosheets cathode exhibits a remarkable capacity of 313.6 mAh g −1 (0.1 A g −1 ), an energy density of 301.4 Wh kg −1 , and a prominent rate capability (168.7 mAh g −1 at 10 A g −1 ).

Layered vanadium phosphate (VOPO4•2H2O) is reported as a promising cathode material for rechargeable aqueous Zn2+ batteries (ZIBs) owing to its unique layered framework and high discharge plateau. However, its sluggish...