Unleashing the potential: SiOx@GNs composites for superior lithium-ion battery anodes

Abstract

SiO_x is commonly used in lithium-ion batteries because of its capacity and affordability, but it has issues with volume expansion and conductivity. Synthetic methods are crucial for achieving the desired microstructure and material properties. This study introduces a new technique, fluidized bed granulation, to produce SiO_x@GNs composites. These composites have a core-shell structure with SiO_x particles coated in graphene sheets, and high-energy vibration is used to create a SiO_x-Fe structure on the surface. The graphene coating prevents volume expansion and enhances electron transfer. Real-time confocal imaging shows the charging and discharging process. Experiment results show that the SiO_x@GNs electrode has a lower expansion rate of 53.60% compared to 73.04% for the SiO electrode, indicating improved electrochemical properties with the graphene coating. After 100 cycles at 2 C, SiO_x@GNs demonstrate a reversible capacity of 1265.8 mA⋅h⋅g⁻¹ and discharge capability at 7 C with a capacity of 1050 mA⋅h⋅g⁻¹. The battery retains 90.21% of its capacity after 500 cycles at 0.5 C, showing potential as a LIB anode alternative with a unique structure for different energy storage materials. Fluidized bed granulation can aid in scaling up the use of SiOx anodes in lithium-ion batteries.