Green, Scalable, and Controllable Fabrication of Nanoporous Silicon from Commercial Alloy Precursors for High-Energy Lithium-Ion Batteries

Abstract

Silicon is considered as one of the most favorable anode materials for next-generation lithium-ion batteries. Nanoporous silicon is synthesized via a green, facile, and controllable vacuum distillation method from the commercial MgSi alloy. Nanoporous silicon is formed by the evaporation of low boiling point Mg. In this method, the magnesium metal from the MgSi alloy can be recycled. The pore sizes of nanoporous silicon can be secured by adjusting the distillated temperature and time. The optimized nanoporous silicon (800 °C, 0.5 h) delivers a discharge capacity of 2034 mA h g at 200 mA g for 100 cycles, a cycling stability with more than 1180 mA h g even after 400 cycles at 1000 mA g, and a rate capability of 855 mA h g at 5000 mA g. The electrochemical properties might be ascribed to its porous structure, which may accommodate large volume change during the cycling process. These results suggest that the green, scalable, and controllable approach may offer a pathway for the commercialization of high-performance Si anodes. This method may also be extended to construct other nanoporous materials.

Solution Synthesis of Porous Silicon Particles as an Anode Material for Lithium Ion Batteries

“…To further elucidate the outstanding performance of the pSi@NC electrode, electrochemical impedance spectroscopy (EIS) measurements were carried out. As shown in Figure S7, the diameters of the semicircle in the EIS spectra of the pSi@NC electrode were not obviously enlarged after the electrode was cycled at various current densities, indicating a good stability of the SEI film during the charge‐discharge processes and the outstanding rate performance . Moreover, the pSi@NC electrode remained flat, without cracking or pulverization, after cycling for 200 times, and the morphology of the nanoparticles was well‐maintained in comparison with the fresh anode (Figure S7).…”

“…successfully fabricated innovative three‐dimensional spongy nanographene‐functionalized silicon substrates for LIBs with excellent long‐term cycling stability and rate performance . Despite the progress that has been made in this field during the past decades, nanostructured silicon materials are still mainly synthesized by etching of silicon templates, chemical vapor deposition, dealloying, and magnesiothermic reduction methods . Recently, Lin et al.…”

Engineering Carbon Distribution in Silicon‐Based Anodes at Multiple Scales

“…[53] In addition, the abundant inner pores can not only accommodate the large mechanical strained induced by the expansion of Si but also provide channels for lithium ion transfer. [59] Subsequently,c arbon coating is performed by either the CVD process or wet chemistry approach. [59] Subsequently,c arbon coating is performed by either the CVD process or wet chemistry approach.…”

Assembly of Si@Void@Graphene Anodes for Lithium‐Ion Batteries: In Situ Enveloping of Nickel‐Coated Silicon Particles with Graphene

“…[15,16] Carbon coating has been reported as an effective approach in fabricating anodes. [17][18][19][20][21][22][23][24][25][26][27] Well-coated carbon shell or carbon interlayers can act as a conductive framework and electrolyte barrier, [28,29] and it can not only facilitate ion transfer but also restrain the growth of unstable SEI films. Among the carbon materials, graphene has attracted much attention due to its large specific surface area, good electronic conductivity and excellent flexibility.…”