One-dimensional hybrid nanocomposite of high-density monodispersed Fe3O4 nanoparticles and carbon nanotubes for high-capacity storage of lithium and sodium†
Abstract
Here we report a simple but effective method to fill carbon nanotube (CNT) channels with a dense distribution of Fe3O4 nanoparticles, to produce Fe3O4@CNT. The resulting novel heterogeneous nanostructure displayed multiple attractive features as an anode material in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). For example, this nanostructure displayed voids that apparently effectively prevented active material from aggregating and helped to accommodate their volumetric expansion during the cycling process. In addition, most solid electrolyte interphases (SEIs) formed on the surfaces of the CNT shells instead of on individual Fe3O4 nanoparticles, limiting the amount of SEIs and increasing the stability of the Fe3O4 nanoparticles. As a result, when tested for LIBs, the Fe3O4@CNT nanocomposite exhibited an excellent rate capacity and cycling performance in half and full cells. A high reversible capacity of 720 mA h g−1 was obtained after 200 cycles at 1 A g−1, and when the current density was increased to 8 A g−1, the specific capacity was 400 mA h g−1. As for SIBs, a specific capacity of 377 mA h g−1 at 0.1 A g−1 was achieved after 300 cycles. The facile synthetic route and unique nanostructure design may be extended to high-performance anode materials for LIBs and SIBs.