Enabling SiO<i>_x</i>/C Anode with High Initial Coulombic Efficiency through a Chemical Pre-Lithiation Strategy for High-Energy-Density Lithium-Ion Batteries

Abstract

Carbon-coated SiO<i>_x</i> microparticles (SiO<i>_x</i>/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 SiO<i>_x</i>/C anode with high initial Coulombic efficiency using the chemical pre-lithiation strategy. The lithium silicate is uniformly pregenerated in SiO<i>_x</i>/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 SiO<i>_x</i>/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 LiNi_0.8Co_0.1Mn_0.1O₂ 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).