Carbon nanotubes (CNTs) as superior support materials for functional nanoparticles (NPs) have been widely demonstrated. Nevertheless, the homogeneous loading of these NPs is still frustrated due to the inert surface of CNTs. In this work, a facile gas-phase pyrolysis strategy that the mixture of ferrocene and CNTs are confined in an isolated reactor with rising temperature is developed to fabricate a carbon-coated Fe₃O₄ nanoparticle/carbon nanotube (Fe₃O₄@C/CNT) composite. It is found the ultra-small Fe₃O₄ NPs (<10 nm) enclosed in a thin carbon layer are uniformly anchored on the surface of CNTs. These structural benefits result in the excellent lithium-ion storage performances of the Fe₃O₄@C/CNT composite. It delivers a stable reversible capacity of 861 mA ·h·g⁻¹ at the current density of 100 mA·g⁻¹ after 100 cycles. The capacity retention reaches as high as 54.5% even at 6000 mA·g⁻¹. The kinetic analysis indicates that the featured structural modification improves the surface condition of the CNT matrix, and contributes to greatly decreased interface impendence and faster charge transfer. In addition, the post-morphology observation of the tested sample further confirms the robustness of the Fe₃O₄@C/CNT configuration.

碳纳米管（CNTs）作为功能性纳米颗粒（NPs）的优良支撑材料已得到广泛证明。但是，由于CNT的惰性表面，这些NP的均匀负载仍然受阻。在这项工作中，开发了一种简便的气相热解策略，即将二茂铁和CNT的混合物限制在温度升高的隔离反应器中，以制造碳包覆的Fe ₃ O ₄纳米颗粒/碳纳米管（Fe ₃ O ₄ @C / CNT）复合材料。发现超小Fe ₃ O ₄包裹在薄碳层中的NP（<10 nm）均匀地锚固在CNT的表面上。这些结构上的好处使Fe ₃ O ₄ @ C / CNT复合材料具有出色的锂离子存储性能。经过100个循环后，它在100 mA·g ^-1的电流密度下可提供861 mA·h·g ^-1的稳定可逆容量。即使在6000mA·g ^-1下，容量保持率也高达54.5％。动力学分析表明，具有特征性的结构改性改善了CNT基体的表面状况，并有助于大大降低界面势垒和更快的电荷转移。此外，对测试样品的形态后观察进一步证实了铁的坚固性₃ O ₄ @ C / CNT配置。