Ultrathin layered double hydroxide (LDH) nanosheets are a promising candidate as the electrode material for energy storage due to the ultrafast mass diffusion and greater specific surface area. As a kind of emerging electrode material, metal nitride plays a vital role in improving the poor conductivity of most supercapacitors. Herein, we design a novel three-dimensional (3D) embedded hierarchical core–shell nanostructure by combining ultrathin CoFe-LDH nanosheets (∼2.5 nm) with porous Cu₃N nanowire arrays (NWAs), in which the ultrathin CoFe-LDH nanosheets are grown from the interior of Cu₃N nanowire cores supported on Cu foam (denoted as Cu₃N@CoFe-LDH). The prepared Cu₃N@CoFe-LDH NWA electrode exhibits a high areal capacitance of 3078 mF cm⁻² at a current density of 1 mA cm⁻², excellent rate capacity (85.8% capacity retention at 20 mA cm⁻²) and superior cycling stability (93.9% retention after 10 000 cycles), making it significantly superior to the related CuO@CoFe-LDH NWA electrodes. Additionally, the constructed asymmetric supercapacitor (ASC) devices deliver an ultrahigh energy density of 2.474 mWh cm⁻³ and a robust cycling stability (92.6% retention after 10 000 cycles). The outstanding electrochemical performance can be credited to the significant enhancement of the specific surface area, charge transport, and mechanical stability by the ultrathin LDH shell, the highly conductive Cu₃N core, and the distinctive embedded core–shell nanostructure.

Vanadium oxides (such as V₂O₅, V₂O₃ and VO₂) hold great promise as electrode materials for energy storage due to their high electrochemical activity, low cost and environmental benignity.

Rechargeable aqueous batteries with Zn²⁺ as a media‐ion are promising candidates for large‐scale energy storage because of their intrinsic safety, low‐cost and high energy‐intensity. Vanadium based cathodic materials have gained significant attention in aqueous zinc‐ion batteries (AZIBs) due to their high capacity and satisfactory cycle stability. However, more facile and efficient fabrication methods should be explored when considering future realistic application. Herein, commercial V₂O₅ cathodes with oxygen vacancies were fabricated through a simple mechanical ball milling method. The results suggest that mechanical force can directly induce the oxygen vacancies in commercial V₂O₅, which significantly enhance the diffusion of Zn ions. The oxygen vacancy−V₂O₅ (O_v−V₂O₅) shows much higher capacity than the pristine commercial V₂O₅ and the cyclic stability reached 2500 times. O_v−V₂O₅ cathode with a facile synthesis technology is a promising candidate for future high‐performance, low‐cost, safe, and environment‐friendly Zn battery devices.