Preparation and research of bimetal-loaded carbon-coated SiO₂ anode materials

Silicon dioxide (SiO₂) is considered a promising anode material for lithium-ion batteries due to its high theoretical specific discharge capacity (1 965 mAh/g) and extremely low cost. However, its high oxygen content leads to poor electrochemical activity. To address this issue, a mesoporous SiO₂ with a particle size of approximately 100 nm was designed and prepared via the sol-gel method, using tetraethyl orthosilicate (TEOS) as the precursor and cetyltrimethylammonium bromide (CTAB) as the template. The prepared SiO₂ particles were subsequently coated using resorcinol formaldehyde resin (RF) as the carbon precursor. Based on the above experiments, Cu²⁺ and Fe³⁺ were doped into the resin layer through a complexation reaction. After high-temperature carbonization, a bimetal-loaded carbon-coated material, SiO₂@Cu-Fe-C, was formed. The synergistic effect generated by the bimetallic loading effectively improved the electrochemical performance of the material. The data showed that the initial Coulombic efficiency (ICE) of SiO₂@Cu-Fe-C was 52.2%. It exhibited a high reversible specific discharge capacity of 719 mAh/g at a current density of 200 mA/g, and maintained an average specific discharge capacity of 570 mAh/g at a current density of 1 000 mA/g after 500 cycles.