Scalable Synthesis of Porous SiFe@C Composite with Excellent Lithium Storage

Utilizing cost‐effective raw materials to prepare high‐performance silicon‐based anode materials for lithium‐ion batteries (LIBs) is both challenging and attractive. Herein, a porous SiFe@C (pSiFe@C) composite derived from low‐cost ferrosilicon is prepared via a scalable three‐step procedure, including ball milling, partial etching, and carbon layer coating. The pSiFe@C material integrates the advantages of the mesoporous structure, the partially retained FeSi2 conductive phase, and a uniform carbon layer (12–16 nm), which can substantially alleviate the huge volume expansion effect in the repeated lithium‐ion insertion/extraction processes, effectively stabilizing the solid–electrolyte interphase (SEI) film and markedly enhancing the overall electronic conductivity of the material. Benefiting from the rational structure, the obtained pSiFe@C hybrid material delivers a reversible capacity of 1162.1 mAh g−1 after 200 cycles at 500 mA g−1, with a higher initial coulombic efficiency of 82.30 %. In addition, it shows large discharge capacities of 803.1 and 600.0 mAh g−1 after 500 cycles at 2 and 4 A g−1, respectively, manifesting an excellent electrochemical lithium storage. This work provides a good prospect for the commercial production of silicon‐based anode materials for LIBs with a high lithium‐storage capacity. Threesome is impressive: A novel and scalable strategy for the fabrication of porous SiFe@C composite with mesoporous structure is reported. The conductive phase of FeSi2 is partially retained; together with a uniform carbon layer excellent lithium storage is achieved.