Facile Synthesis of Double-Layer-Constrained Micron-Sized Porous Si/SiO2/C Composites for Lithium-Ion Battery Anodes

• DOI: 10.1021/acsami.9b12596
• Publication Date: 2019-09-23T15:27:52Z
• Authors: Kai Wang; Yi Tan; Pengting Li; Bing Xue; Jianming Sun
• Keywords: Void (composites)

Advanced Si-based anode materials with nano-sized porous structures and constrained coating layers present attractive prospects for lithium-ion batteries. A brand-new design of double-layer-constrained micron-sized (>20 μm) Si/SiO2/C is proposed through facile synthesis processes using cheap Al–Si alloy as feedstock. The three-dimensional spherical coral-like Si structure composed primary (as a supporting framework), eutectic rods, uniformly distributed conductive element Al, which beneficial providing void space sites. 4 nm SiO2 thin layer introduced on the surface preoxidation treatment, has effect to constrain volume expansion Si. outer C can further improve electrical conductivity structural stability. discharge charge capacities Si1/SiO2/C composite are 933.3 929.2 mAh/g at 0.1 A/g after 100 cycles, respectively. attenuation rate in each loop only 0.08%, diffusion coefficient this 4.20 × 10–12 cm2·s–1/2.