Hollow silica microspheres/graphene and silica@titanium dioxide core–shell microspheres/graphene as enhanced lithium-ion battery anodes

Electric vehicles and energy storage demand better anode materials than are currently available. Silicon-based materials are highly esteemed for their elevated specific capacity, but their substantial volume alteration during cycling and inadequate intrinsic electronic conductivity result in significant performance constraints. This paper used polystyrene microspheres as a template to make silica microspheres. These silica microspheres formed two materials: To create hollow silica microspheres (H-SiO₂), remove the template using high-temperature calcination. To create silica-titanium dioxide core–shell microspheres (SiO₂@TiO₂), coat titanium dioxide on silica microspheres using sol–gel. After mixing with graphene oxide hydrothermally, the two materials formed hollow silica microspheres/graphene (H–SiO₂/rGO) and silica-titanium dioxide core–shell microspheres/graphene (SiO₂@TiO₂/rGO). These two materials exhibit distinct performance benefits. H–SiO₂/rGO composite anode material demonstrates a notable specific capacity of 835 mAh g⁻¹ when subjected to a current density of 100 mA g⁻¹. SiO₂@TiO₂/rGO composite anode material is durable and consistent, even at high current densities. After 1500 cycles at 1000 mA g⁻¹, its specific capacity is 405.71 mAh g⁻¹. Additionally, at ultra-high current densities of 5000 and 8000 mA g⁻¹, it has a specific capacity of 313.47 and 288.37 mAh g⁻¹.