Porous Nano-Si/Carbon Derived from Zeolitic Imidazolate Frameworks@Nano-Si as Anode Materials for Lithium-Ion Batteries

Novel porous cage-like carbon (C)/nano-Si nanocomposites as anode materials for lithium-ion batteries (LIBs) was prepared based on nano-Si@zeolitic imidazolate frameworks (ZIF-8)-templated method. In this strategy, p-aminobenzoic acid was initially grafted onto nano-Si to form benzoic acid-functionalized nano-Si, and then nano-Si@ZIF-8 was constructed by alternately growing Zn(NO 3 ) 2 ·6H 2 O and 2-methylimidazolate on benzoic acid-functionalized nano-Si under ultrasound. The novel porous cage-like nano-Si/C nanocomposites were fabricated by pyrolyzing the resulted nano-Si@ZIF-8 and washing with HCl to remove off ZnO. Scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, Raman spectra and N 2 adsorption/desorption isotherms were employed to characterize the porous cage-like nano-Si/C nanocomposites. The resulted nano-Si/C nanocomposites as anode materials for LIBs showed a high reversible capacity of ∼1168   mA   h   g −1 at 100   mA   g −1 after 100 cycles, which was higher than many previously reported Si/C nanocomposites. The porous nanostructure, high specific surface area and good electrical conductivity of the cage-like nano-Si/C nanocomposites contributed together to the good performance for LIBs. It might open up a new way for application of silicon materials.