Loo, Bing QinBing QinLooLau Jr, VictorVictorLau JrYang, Nai‐WeiNai‐WeiYangTsui, Li‐yanLi‐yanTsuiHsu, Hsiao‐PingHsiao‐PingHsuCHUNG-WEN LAN2025-07-302025-07-302025-0621944288https://www.scopus.com/record/display.uri?eid=2-s2.0-105008908549&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/730820Metal reduction of silicon gases is a widely explored route for synthesizing low-dimensional nanosilicon materials; however, achieving specific nanostructures often requires templates that are challenging to produce or expensive. This study proposes a cost-effective and scalable approach by ball-milling aluminum into thin flakes (<50 nm), which serve both as reductants and physical templates for the direct gas-phase synthesis of silicon nanosheets. The study demonstrates that performing the synthesis in the gas phase enables highly controlled surface reactions, crucial for forming well-defined silicon nanosheets. The reduction of industrial by-product silicon tetrachloride occurs via a solid–gas reaction at a relatively low temperature of 225 °C in a closed autoclave system. The resulting silicon nanosheets demonstrate uniform morphology (≈20 nm thick) and a high surface-to-thickness ratio favorable for lithium-ion battery anode applications. Electrochemical tests achieve a high initial capacity of 4038 mAh g−1 and a Coulombic efficiency of 83.3%. The nanosheets retain a reversible capacity of 2058 mAh g−1 after 250 cycles at 2.1 A g−1 and excellent rate capability, recovering 87% capacity at 21 A g−1.falsealuminumlithium-ion batteriesnanosheetsnanostructuresreductionsilicontemplate[SDGs]SDG7[SDGs]SDG11journal article10.1002/ente.2025003402-s2.0-105008908549