Na-containing bilayer vanadium oxides offer outstanding storage capabilities for lithium and sodium batteries, but a multistep process for chemical pre-intercalation of Na-ion exposes a limitation for the application. Herein, we propose a facile one-pot hydrothermal approach to synthesize well crystallized bilayer Na_xV₂O₅·nH₂O with ketjen black as conductive dense-network. As a cathode in sodium-ion batteries, the resultant Na_xV₂O₅·nH₂O/ketjen black nanocomposite exhibits a high specific capacity of 239 mA h g^-1 at a current density of 20 mA g⁻¹ as well as an enhanced rate performance at high current rates up to 640 mA g⁻¹. Ex situ XRD and XPS analysis are conducted to demonstrate the high specific capacity and investigate the changes in structure. Moreover, it is noticeable that two pronounced voltage plateaus reflect the high electrochemical activity of V⁴⁺/V⁵⁺, contributing to a remarkable energy density of 597 Wh kg⁻¹, which is one of the highest records for cathode of sodium-ion batteries ever reported.

含钠的双层钒氧化物为锂和钠电池提供了出色的存储能力，但是对钠离子进行化学预嵌入的多步骤工艺为该应用带来了局限性。在此，我们提出了一种容易的一锅热液方法来合成结晶良好的Na双层_X V ₂ ø ₅ · Ñ ħ ₂ ö与科琴黑作为导电密集网络。作为钠离子电池的阴极，所得的Na _x V ₂ O ₅ · n H ₂ O /科琴黑色纳米复合材料在20 mA g的电流密度下显示出239 mA h g ^-1的高比容量。^-1以及高达640 mA g ^-1的高电流速率下的增强的速率性能。进行了异位XRD和XPS分析，以证明其高比容量并研究结构的变化。此外，值得注意的是，两个明显的电压平稳期反映出V ⁴⁺ / V ⁵⁺的高电化学活性，有助于产生显着的597 Wh kg ^-1能量密度，这是钠离子阴极的最高记录之一电池曾有报道。