This pre-lithiated silicon oxide material, designated Silicon oxide (1400) - A, is developed as a high-capacity anode material for lithium-ion batteries. It features a sub-micron particle size distribution (D50 around 8 μm) with a low BET specific surface area of ≤0.9 m²/g, facilitating good processability and electrode coating uniformity. Electrochemical testing in half cells using NCM electrolyte demonstrates a first reversible capacity exceeding 1400 mAh/g at 1.5 V cutoff, with a first coulombic efficiency of at least 88%. The material is free from a distinct silicon peak and shows low trace metal and magnetic substance contamination, supporting stable cycling. It is typically applied in advanced battery research requiring high energy density anodes. The product is vacuum-sealed in aluminum-plastic film and should be stored in a cool, dry environment to maintain its pre-lithiated state.