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Indexed by:Journal Papers

Date of Publication:2019-10-16

Journal:ACS APPLIED MATERIALS & INTERFACES

Included Journals:EI、SCIE

Volume:11

Issue:41

Page Number:37732-37740

ISSN No.:1944-8244

Key Words:porous Si; spherical coral-like structure; porous Si/SiO2/C; electrical performance; lithium-ion batteries

Abstract: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 mu m) porous Si/SiO2/C is proposed through facile synthesis processes using cheap Al-Si alloy as feedstock. The three-dimensional spherical coral-like porous Si structure is composed of primary Si (as a supporting framework), eutectic Si rods, and uniformly distributed conductive element Al, which is beneficial for providing void space and uniformly conductive sites. A 4 nm SiO2 thin layer is introduced on the surface of porous Si structure using preoxidation treatment, which has the effect to constrain the volume expansion of Si. The outer C layer can further improve the electrical conductivity and structural stability. The discharge and charge capacities of the porous Si1/SiO2/C composite are 933.3 and 929.2 mAh/g at 0.1 A/g after 100 cycles, respectively. The charge attenuation rate of porous Si1/SiO2/C in each loop is only 0.08%, and the lithium-ion diffusion coefficient of this composite is 4.20 X 10(-12) cm(2).s(-1/2).