Synthesis of carbon-coated FeOx nanoparticles via spray solidification as anode materials for high-performance lithium-ion batteries

To restrict the volume expansion of FeOx nanoparticles were used as anode materials in lithium-ion batteries during charge-discharge processes, FeOx nanoparticles were coated with carbon via a facile and mass-producible spray solidification method. Consequently, FeOx nanoparticles were encapsulated in a thin carbon layer, sup-pressing their volume expansion and providing excellent electrical conductivity during charge-discharge pro-cesses. The FeOx/C nanoparticles without carbon coating provided initial discharge capacities of 1192.8 and 100.8 mA h g-1 at current densities of 0.1 and 5 A g-1, respectively, and a reversible capacity of 269.9 mA h g-1 after C-rate testing and 600 cycles at a current density of 1 A g-1. Compared with a pure FeOx/C electrode, the FeOx/4C electrode with an optimum carbon coating content exhibits outstanding electrochemical properties, exhibiting discharge capacities of 1224.5 and 482.2 mA h g-1 at current densities of 0.1 and 5 A g-1, respec-tively, and a reversible capacity of 735.8 mA h g-1 after C-rate testing and 600 cycles at a current density of 1 A g-1. This indicates that carbon coating improves the electrochemical performance of FeOx nanoparticles. The proposed synthesis method provides a facile and feasible route for the large-scale production of nanoparticles as electrode materials for lithium-ion batteries.