Nowadays, ca. 176,640 tons/year of silicon (Si) is manufactured for Si wafers used for semiconductor industry. The production of the highly pure Si wafers inevitably includes very high-temperature steps at 1400–2000?°C, which is energy-consuming and environmentally unfriendly. Inefficiently, ca. 45–55% of such costly Si is lost simply as sawdust in the cutting process. In this work, we develop a cost-effective way to recycle Si sawdust as a high-performance anode material for lithium-ion batteries. By a beads-milling process, nanoflakes with extremely small thickness (15–17?nm) and large diameter (0.2–1??m) are obtained.