In this study, a nitrogen–boron codoped carbon layer, Na₃V₂(PO₄)₂F₃ sample, obtained by using an ionic liquid–acrylic acid copolymer as the nitrogen–boron source was used as the cathode material for sodium-ion batteries. The optimized and modified nitrogen and boron codoped carbon layer, Na₃V₂(PO₄)₂F₃ (denoted as NVPF-PCNB-20), illustrated better rate capability and cycling performance. The discharge capacities of NVPF-PCNB-20 at 0.5C and 10C were 109 and 90 mAh g^–1, respectively, and the capacity retention rate was 93.2% after 100 cycles at 0.5C and 92.8% after 750 cycles at 10C. Through in situ X-ray diffraction analysis of NVPF-PCNB-20, the results show that the modified Na₃V₂(PO₄)₂F₃ has excellent cycle reversibility. The scanning electron microscopy and transmission electron microscopy images reveal that NVPF-PCNB-20 particles were finer and covered by a uniform coating. The results show that the ionic liquid–acrylic acid copolymer not only make the material dispersion more uniform but also enhance the electronic conductivity and sodium storage performance of Na₃V₂(PO₄)₃F₃ effectively. This study may provide an effective way to synthesize nitrogen and boron codoped carbon-coated Na₃V₂(PO₄)₂F₃ with excellent electrochemical performance.

中文翻译：

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离子液体-丙烯酸共聚物衍生氮-硼共掺杂碳包覆Na3V2(PO4)2F3作为高性能钠离子电池的正极材料

在本研究中，以离子液体-丙烯酸共聚物作为氮-硼源获得的氮-硼共掺杂碳层 Na ₃ V ₂ (PO ₄ ) ₂ F ₃被用作钠离子电池的正极材料。离子电池。优化和改性的氮和硼共掺杂碳层Na ₃ V ₂ (PO ₄ ) ₂ F ₃ (表示为NVPF-PCNB-20)显示了更好的倍率性能和循环性能。NVPF-PCNB-20 在 0.5C 和 10C 的放电容量分别为 109 和 90 mAh g ^–1, 分别在 0.5C 下循环 100 次后容量保持率为 93.2%，在 10C 下循环 750 次后容量保持率为 92.8%。通过对NVPF-PCNB-20进行原位X射线衍射分析，结果表明改性Na ₃ V ₂ (PO ₄ ) ₂ F ₃具有优异的循环可逆性。扫描电子显微镜和透射电子显微镜图像显示 NVPF-PCNB-20 颗粒更细，并被均匀的涂层覆盖。结果表明，离子液体-丙烯酸共聚物不仅使材料分散更均匀，而且提高了Na ₃ V ₂ (PO ₄ ) _{3的电子电导率和储钠性能。}F ₃有效。本研究为合成具有优异电化学性能的氮硼共掺杂碳包覆Na ₃ V ₂ (PO ₄ ) ₂ F _{3提供了一种有效途径。}