Two-step synthesis of nanohusk Fe3O4 embedded in 3D network pyrolytic marine biochar for a new generation of anode materials for Lithium-Ion batteries

Abstract

Two-step preparation of nanohusk Fe3O4 embedded in 3D network biochar was achieved by a facile slow pyrolysis process at 700 °C and hydrothermal gasification method. To reach material sustainability, a macroalga, namely Cladophora glomerata was used as carbon resource in this study. Based on structural characterizations by XRD, Raman, FTIR, FESEM, BET, and XPS analyses, it has been found that crystalline Fe3O4 particles are embedded in an amorphous olive shaped carbon matrix and created a 3D network carbon. When the 3D network carbon tested as an anode electrode in Lithium-Ion batteries (LIBs), showed a high initial specific discharge capacity of 1307 mAh g−1 at 100 mA g−1, good cycleability, and excellent rateability. Moreover, a stable reversible capacity of 551.7 mAh g−1 at 500 mA g−1 with the negligible capacity fade during charge and discharge process could be related to the high surface area, the presence of macro/meso porous structures, and iron crystals in 3D network carbon. Electrochemical Impedance Spectroscopy (EIS) and differential capacity analyses also showed the negligible decrease in Li+ diffusion coefficient and the safeguard the structural integrity of Fe3O4 by using carbon derived from biomass after charge and discharge processes.