Anchored Fe3O4 Nanoparticles on rGO Nanosheets as High-Power Negative Electrodes for Aqueous Batteries

Fe3O4 nanoparticles were anchored on GO nanosheets and evaluated as negative electrode materials for high-performance aqueous batteries. The prepared samples were characterized by using XRD, Raman spectroscopy, TGA, and TEM. The energystorage behavior of the samples was investigated by testing high-mass-loaded (ca. 8.5 mg.cm(-2)) Fe3O4-rGO electrodes with different electrochemical techniques, including cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. The nanocomposites showed better electrochemical storage properties than pure Fe3O4 nanoparticles and rGO nanosheets, suggesting superior performance through synergistic effects. Accordingly, the Fe3O4-rGO nanocomposite with an optimized composition of [60 : 40] showed a maximum capacity of 402 C.g(-1) (111.6 mA.h. g(-1)) and superior rate capability (ca. 40% capacity retention with a 20-fold increase in scan rate) compared to the pure oxide. To further evaluate the applicability of the Fe3O4-rGO nanocomposite, aqueous batteries based on the Fe3O4-rGO [60 : 40] nanocomposite as negative electrodes and NiCoMnO4 as positive electrodes were assembled and examined by using various electrochemical techniques. Fe3O4-rGO//NiCoMnO4 cells demonstrated a maximum specific energy of 26 Wh.kg(-1) and a maximum specific power of 6.8 kW.kg(-1), with a desirable rate capability. All of the obtained results suggest the Fe3O4-rGO nanocomposite as a promising negative electrode material for high-power aqueous batteries.