The abundant sodium resources makes sodium ion batteries have the potential to be an alternative to lithium-ion batteries. Due to the large ionic radius of sodium ion, suitable cathode materials have a significant impact on the electrochemical performance of sodium ion batteries. Herein, Cu_0.18V₂O₅•0.72H₂O/ Ketjen black, a double modification strategy of groups (Cu²⁺/H₂O) intercalation and Ketjen black composition materials was successfully synthesized. Copper ions and water molecules co-inserted into the V₂O₅ interlayer to increase its spacing, thus increasing the active sites of Na⁺ ions intercalation and deintercalation. Meanwhile, the interlayer groups serve as “pillars” to improve the structural stability of the material. Ketjen black not only reduces particle aggregation but also enhances electrical conductivity of the material. As the cathode of sodium-ion batteries, the combination of these factors allows the cathode to exhibit high reversible specific capacity (up to 155 mA h g⁻¹ at 50 mA g⁻¹) and superior cycle performance. The fast and highly reversible Na⁺-ion intercalation/deintercalation mechanism was revealed by in situ XRD.

丰富的钠资源使得钠离子电池有潜力成为锂离子电池的替代品。由于钠离子的离子半径较大，合适的正极材料对钠离子电池的电化学性能有重大影响。成功合成了基团(Cu²⁺/H₂Cu_0.18V₂O₅•0.72H₂铜离子和水分子共同插入V₂O₅⁺的活性位点。同时，层间基团充当“支柱”，提高材料的结构稳定性。科琴黑不仅可以减少颗粒聚集，还可以增强材料的导电性。作为钠离子电池的正极，这些因素的结合使得正极表现出高可逆比容量（在50 mA g^-1-1）和优异的循环性能。通过原位 XRD 揭示了快速且高度可逆的 Na⁺