In-Situ Crafting of ZnFe₂O₄ Nanoparticles Impregnated within Continuous Carbon Network as Advanced Anode Materials

The ability to create a synergistic effect of nanostructure engineering and its hybridization with conductive carbonaceous material is highly desirable for attaining high-performance lithium ion batteries (LIBs). Herein, we judiciously crafted ZnFe₂O₄/carbon nanocomposites composed of ZnFe₂O₄ nanoparticles with an average size of 16 ± 5 nm encapsulated within the continuous carbon network as anode materials for LIBs. Such intriguing nanocomposites were yielded in situ via the pyrolysis-induced carbonization of polystyrene@poly(acrylic acid) (PS@PAA) core@shell nanospheres in conjunction with the formation of ZnFe₂O₄ nanoparticles through the thermal decomposition of ZnFe₂O₄ precursors incorporated within the PS@PAA nanospheres. By systematically varying the ZnFe₂O₄ content in the ZnFe₂O₄/carbon nanocomposites, the nanocomposite containing 79.3 wt % ZnFe₂O₄ was found to exhibit an excellent rate performance with high capacities of 1238, 1198, 1136, 1052, 926, and 521 mAh g^-1 at specific currents of 100, 200, 500, 1000, 2000, and 5000 mA g^-1, respectively. Moreover, cycling performance of the ZnFe₂O₄/carbon nanocomposite with 79.3 wt % ZnFe₂O₄ at specific currents of 200 mA g^-1 delivered an outstanding prolonged cycling stability for several hundred cycles.