Fe₃O₄ Nanoparticles on 3D Porous Carbon Skeleton Derived from Rape Pollen for High-Performance Li-Ion Capacitors

Herein, a three-dimensional (3D) Fe₃O₄@C composite with hollow porous structure is prepared by simple solution method and calcination treatment with biomass waste rape pollen (RP) as a carbon source, which is served as an anode of Li-ion capacitor (LIC). The 3D interconnected porous structure and conductive networks facilitate the transfer of ion/electron and accommodate the volume changes of Fe₃O₄ during the electrochemical reaction process, which leads to the excellent performance of the Fe₃O₄@C composite electrode. The electrochemical analysis demonstrates that the hybrid LIC fabricated with Fe₃O₄@C as the anode and activated carbon (AC) as the cathode can operate at a voltage of 4.0 V and exhibit a high energy density of 140.6 Wh kg^-1 at 200 W kg^-1 (52.8 Wh kg^-1 at 10 kW kg^-1), along with excellent cycling stability, with a capacity retention of 83.3% over 6000 cycles. Hence, these encouraging results indicate that Fe₃O₄@C has great potential in developing advanced LICs electrode materials for the next generation of energy storage systems.