Iron and silicon oxide doped/PAN-based carbon nanofibers as free-standing anode material for Li-ion batteries

The advanced rechargeable batteries have been upgraded by the production of free-standing electrodes through electrospinning technology. This study aimed to introduce a novel hybrid composition to design a free-standing carbon nanofiber (CNF) based anode by the addition of iron acetylacetonate Fe(AcAc)₃ as active material and TEOS(tetraethoxysilane)/APTES(aminopropyl triethoxysilane) as an additive for Li-ion batteries. Polyacrylonitrile(PAN) was used as the polymer matrix in the spin dope, and the inclusion of Fe(AcAc)₃ and TEOS/APTES resulted in compositional change, producing iron oxide and silica nanoparticles throughout the matrix. Different oxidation states and the presence of embedded iron oxide nanoparticles in CNF were identified by XPS and EDX elemental mapping analysis. PAN-TEOS-APTES-Fe(AcAc)₃ based anode material was capable of enhancing the reversible specific capacity as much as 732 mAhg^-1 at 500 mAg^-1 lasting for 300 cycles, along with the rate capability as high as 815 mAhg^-1 at 200 mAg^-1. Furthermore, EIS analysis and EX-situ FESEM showed decreased impedance after cycling with the stable morphology of PAN-TEOS-APTES-Fe(AcAc)₃ CNF-film. Conclusively, non-woven, binder-free, current collector free, free-standing CNF anode film doped with iron-oxide and silica nanoparticles was indeed a novel approach for Li-ion batteries and can be considered for other batteries particularly for Li-S batteries.