The facile preparation and performances of prelithiated silicon oxide anode materials

Silicon oxide (SiO_x) anode materials have gained significant attention in lithium-ion batteries due to their high theoretical specific capacity (above 1965 mAh g⁻¹), relatively stable cycling performance, and lower production costs. However, SiO_x anode materials tend to form a solid electrolyte interphase (SEI) film and generate inert substances like Li₂O and Li₄SiO₄ during the initial charge and discharge processes, leading to the consumption of active lithium ions and low initial coulombic efficiency. To address these issues effectively, prelithiation of SiO_x anode materials is explored in this study. A lithium powder suspension is prepared by dispersing lithium powder and carbon nanotubes (CNTs) in the electrolyte, served as the prelithiation agent. The SiO/G@C@A anode material is then prelithiated with this agent. The lithium powder suspension prelithiation agent enables effective prelithiation of the anode material. The SiO@C@A-1 anode exhibits improved electrochemical performances. At a current density of 0.1 A g⁻¹, the initial specific capacity reaches 981.3 mAh g⁻¹ with an initial coulombic efficiency of 95.65%, which is approximately 25% higher than that of the untreated sample. After 100 cycles and at a current density of 0.5 A g⁻¹, the prelithiated sample retains a discharge specific capacity of 648 mAh g⁻¹, with a capacity retention rate of 83.27%, around 10% higher than that of the untreated sample, demonstrating excellent cycling performances.