Metal-Catalyzed Nanostructured Silicon Films as Potential Anodes for Flexible Rechargeable Batteries

Nanostructured Si is touted to be an inexpensive, safe, and high-capacity anode for advanced thin-film batteries. However, the synthesis of crystalline Si generally requires high temperatures, which limits the choice of substrates. In this study, we synthesized nanostructured Si layers at low temperatures by combining metal-catalyzed crystal growth and etching. The lower crystallinity and finer nanostructures in Si improved the anode characteristics of Li-ion batteries. The capacity of the Si anode reached approximately 3200 mAh g–1 at 0.1 C and 2000 mAh g–1 at 1 C. Further, the low process temperature enabled the fabrication of a Si layer of the same quality on a flexible plastic substrate while maintaining the flexibility. This low-temperature synthesis of nanostructured Si anodes is therefore expected to pioneer the next generation of human-friendly flexible rechargeable batteries.