Nanoweb anodes composed of one-dimensional, high aspect ratio, size tunable electrospun ZnFe₂O₄ nanofibers for lithium ion batteries

Nanowebs consisting of interwoven ZnFe₂O₄ nanofibers are synthesized by a simple electrospinning technique, to be employed as an environmentally friendly anode in lithium ion batteries. Effect of precursor viscosity on the growth mechanism of electrospun ZnFe₂O₄ nanofibers (ZFO-NF) and ZnFe₂O₄ nanorods (ZFO-NR) is studied by microscopy and diffraction techniques. Structural characterization by powder X-ray diffraction, FESEM and HRTEM studies evaluates the single phase nature of ZnFe₂O₄, which consists of 11(3) nm nanocrystals that self-agglomerate to form nanofibers after thermal treatment. FESEM micrographs depict the self-assembly of electrospun ZnFe₂O₄ nanofibers into intertwined porous nanowebs with a continuous framework. Benefitting from the one-dimensional functional nanostructured architecture, the application of electrospun nanowebs with ZnFe₂O₄ nanofiber (ZFO-NF) anodes in lithium ion batteries exhibits excellent cyclability and retains a reversible capacity of 733(10) mAh g^-1 up to 30 cycles at 60 mA g^-1 as compared to ZnFe₂O₄ nanorods (ZFO-NR) with a capacity of ∼200 mAh g^-1. In addition, the importance of providing electronic wiring during lithiation/delithiation, especially in prolonged cycling, is emphasized.