SiO2/Carbon Composite Microspheres with Hollow Core-Shell Structure as a High-Stability Electrode for Lithium-Ion Batteries

The SiO2/carbon composite material used as a lithium-ion battery (LIB) anode was synthesized by aerosol spraying a mixture of polyvinyl alcohol (PVA) solution and SiO2 nanoparticles, followed by coating polyacrylonitrile (PAN) on the SiO2/PVA surface and an annealing treatment at 800 degrees C. The as-prepared SiO2/po-C@C has a hollow core-shell structure. The hollow section contributes to accommodate the volume expansion of SiO2 nanoparticles; the skeleton of porous carbon in the core not only enhances the electronic conductivity, but also provides the lithium-ion diffusion path; the PAN-based carbon shell benefits for forming a stable solid electrolyte interphase (SEI) film. This core-shell structure could partly alleviate the pulverization of the SiO2/po-C@C particles and also perform excellent electrochemical performances. Compared with the SiO2@C composite, the SiO2/po-C@C composite possesses a high specific charge capacity of 669.8mAhg(-1) at a current density of 100mAg(-1) after 100 charge and discharge cycles with a high capacity retention of 98.6%. Therefore, the SiO2/po-C@C composite with a hollow core-shell structure shows great potential as an anode material for future LIBs.