Abstract Carbon-based supercapacitive materials are promising energy storage materials because of their high power density and long durability. The energy density of carbon based materials can be significantly improved by making their hybrids with metal/metal oxides and hydroxides. Here, we successfully fabricated the electrospun carbon nanofibers (CNFs) with Fe encapsulated carbon nanotubes (CNTs) by simple chemical vapor deposition (CVD). The Fe nanoparticles later got oxidized by absorbing oxygen from air resulting in the desired hierarchical Fe/Fe3O4 encapsulated CNT/CNF nanostructure (Fe/Fe3O4@CNT-CNF). The composite material showed a high specific capacitance of 195 F g-1 at 0.5 A g-1, areal capacitance of 398 m F cm-2 in 1 M KOH and long term durability with 95% capacitance retention even after 5000 charge discharge cycles. The findings of our results suggest that Fe/Fe3O4@CNT-CNF hybrid is a potential candidate for electrode material of an electrochemical capacitor due to its distinctive nanoarchitectures and physiochemical properties.

中文翻译：

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在用于高性能超级电容器电极的碳纳米纤维上生长的碳纳米管中封装 Fe/Fe3O4

摘要 碳基超级电容材料具有高功率密度和长寿命等优点，是很有前景的储能材料。通过将碳基材料与金属/金属氧化物和氢氧化物混合，可以显着提高碳基材料的能量密度。在这里，我们通过简单的化学气相沉积 (CVD) 成功地制造了带有 Fe 封装的碳纳米管 (CNT) 的电纺碳纳米纤维 (CNF)。Fe 纳米粒子后来通过从空气中吸收氧气而被氧化，从而产生所需的分层 Fe/Fe3O4 封装的 CNT/CNF 纳米结构（Fe/Fe3O4@CNT-CNF）。该复合材料在 0.5 A g-1 下显示出 195 F g-1 的高比电容，在 1 M KOH 中的面积电容为 398 m F cm-2，并且即使在 5000 次充放电循环后仍具有 95% 的电容保持率的长期耐久性。