In this work, nitrogen-doped carbon-coated NaV₃O₈ (NVO@NC) were successfully synthesized by a simple rheological phase method using melamine as a nitrogen source. X-ray powder diffraction (XRD) and Scanning electron microscopy (SEM) analyses revealed that nitrogen-doped carbon-coated didn't change the crystal structure of NVO but altered the thickness and properties of the surface coating. Among obtained composites, NVO@NC containing a molar ratio of melamine to citric acid of 2.75:1.25 displayed the best electrochemical properties. The electrochemical tests suggested discharge capacity reaching 231.3 mAh g⁻¹ at 150 mA g⁻¹, with discharge capacity remaining at 169.4 mAh g⁻¹ after 100 cycles. Electrochemical impedance spectroscopy (EIS) proved that the coated materials delivered a much lower resistance than that of bulk NVO. Galvanostatic intermittent titration technique (GITT) tests demonstrated sodium ion diffusion coefficient was greatly enhanced after nitrogen-doped carbon coating. In conclusion, nitrogen-doped carbon might increase material conductivity, aid in the formation of SEI films on electrode surfaces, and improve electrode material stability, resulting in NVO materials with high-capacity and ultrafast Na-ion storage.

在这项工作中，以三聚氰胺为氮源，通过简单的流变相法成功合成了氮掺杂碳包覆的 NaV ₃ O _{8 (NVO@NC)。}X 射线粉末衍射 (XRD) 和扫描电子显微镜 (SEM) 分析表明，氮掺杂碳涂层不会改变 NVO 的晶体结构，但会改变表面涂层的厚度和性能。在获得的复合材料中，三聚氰胺与柠檬酸的摩尔比为 2.75:1.25 的 NVO@NC 表现出最好的电化学性能。电化学测试表明放电容量 在 150 mA g ^{-1时达到 231.3 mAh g -1}，放电容量保持在 169.4 mAh g ^-1100 次循环后。电化学阻抗谱 (EIS) 证明，涂层材料的电阻比块状 NVO 低得多。恒电流间歇滴定技术（GITT）测试表明，氮掺杂碳涂层后钠离子扩散系数大大提高。总之，氮掺杂碳可能会增加材料的导电性，有助于在电极表面形成 SEI 膜，并提高电极材料的稳定性，从而产生具有高容量和超快钠离子存储的 NVO 材料。