Carbon-coated SiOx microparticles (SiOx/C) demonstrate attractive potential for anode use in high-energy-density lithium-ion batteries due to high capacity and proper cycling stability. However, the excessive irreversible consumption of Li ions during the initial cycling remains a serious challenge arising from the limited lithium in full cells. Here, we endow SiOx/C anode with high initial Coulombic efficiency using the chemical pre-lithiation strategy. The lithium silicate is uniformly pregenerated in SiOx/C microparticles, which could effectively counteract the irreversible consumption of Li ions and avoid the complicated pre-lithiation process. Moreover, this strategy guarantees the structural integrity and processability of anode materials because of the homogeneous Li-organic complex solution pre-lithiation and high-temperature calcination process. The obtained SiOx/C microparticles can be applied as anode materials by directly mixing with commercial graphite, which demonstrates proper specific capacity, high initial Coulombic efficiency, and excellent cycling performance. Furthermore, the pouch cells using LiNi0.8Co0.1Mn0.1O2 cathodes and the as-prepared anodes exhibit high energy density (301 Wh kg-1) and satisfactory cycling stability (93.3% capacity retention after 100 cycles).
Keywords: SiOx; anodes; chemical pre-lithiation; initial Coulombic efficiency; lithium-ion batteries.