Recent progress on boosting initial Coulombic efficiency of SiOx-based anode materials for lithium-ion batteries

SiO x -based (0 < x ≤ 2) materials have emerged as highly promising anode candidates for next-generation lithium-ion batteries (LIBs), combining the advantages of high theoretical capacity (∼2400 mAh g −1 ), cost-effectiveness, and environmental benignity with superior cycling stability compared to pure Si anodes. The inherent formation of lithium oxide and lithium silicate phases during initial lithiation provides an effective buffering matrix that mitigates volume expansion during subsequent cycling. However, the practical implementation of SiO x -based anodes faces a critical challenge: their low initial Coulombic efficiency (ICE) caused by irreversible lithium consumption, which significantly compromises the energy density of full-cell configurations. Therefore, for the practical application of SiO x -based materials, it is urgent to develop available strategies to reduce/compensate for their large initial irreversible capacity. Here, this review systematically examines: (1) fundamental lithiation mechanism of SiO x -based materials; (2) the mechanisms governing ICE limitations in SiO x materials; (3) recent advances in ICE-enhancement strategies including: (i) pre-lithiation strategies, (ii) materials design (surface modification and composition engineering), (iii) electrode and cell design (advanced binders and electrolyte design). By critically analyzing the merits and challenges of each approach, we provide valuable insights for developing commercially viable SiO x -based anodes for next-generation high-energy-density LIBs. • We clarify the lithiation mechanisms of SiOx, delineating the causes of its low ICE into essential and interfacial irreversibility • ICE improvements in SiOx are realized through pre-lithiation, material designs, and optimized electrode/cell components. • The material design strategies, including surface modifications and bulk engineering, enhance the ICE of SiOx