Preparation of a Si/SiO₂–Ordered‐Mesoporous‐Carbon Nanocomposite as an Anode for High‐Performance Lithium‐Ion and Sodium‐Ion Batteries

Abstract

In this work, an Si/SiO -ordered-mesoporous carbon (Si/SiO -OMC) nanocomposite was initially fabricated through a magnesiothermic reduction strategy by using a two-dimensional bicontinuous mesochannel of SiO -OMC as a precursor, combined with an NaOH etching process, in which crystal Si/amorphous SiO nanoparticles were encapsulated into the OMC matrix. Not only can such unique porous crystal Si/amorphous SiO nanoparticles uniformly dispersed in the OMC matrix mitigate the volume change of active materials during the cycling process, but they can also improve electrical conductivity of Si/SiO and facilitate the Li /Na diffusion. When applied as an anode for lithium-ion batteries (LIBs), the Si/SiO -OMC composite displayed superior reversible capacity (958 mA h g at 0.2 A g after 100 cycles) and good cycling life (retaining a capacity of 459 mA h g at 2 A g after 1000 cycles). For sodium-ion batteries (SIBs), the composite maintained a high capacity of 423 mA h g after 100 cycles at 0.05 A g and an extremely stable reversible capacity of 190 mA h g was retained even after 500 cycles at 1 A g . This performance is one of the best long-term cycling properties of Si-based SIB anode materials. The Si/SiO -OMC composites exhibited great potential as an alternative material for both lithium- and sodium-ion battery anodes.

A Flexible Si@C Electrode with Excellent Stability Employing an MXene as a Multifunctional Binder for Lithium‐Ion Batteries

“…Figure a shows the cyclic voltammetry (CV) curves of the MXene‐bonded Si@C film for the first three cycles at 0.1 mV s −1 . A broad peak that appears in the range of 1.6–0.4 V during the initial cathodic scan and disappears in the subsequent cycles can be ascribed to the formation of an SEI layer . The cathodic peak at approximately 0.23 V results from alloying of Li x Si, and the anodic peak at approximately 0.5 V is related to dealloying of Li x Si .…”

“…Figure 5a shows the cyclic voltammetry (CV) curveso f the MXene-bonded Si@C film for the first three cycles at 0.1 mV s À1 .Ab road peak that appears in the range of 1.6-0.4 V during the initial cathodic scan and disappears in the subsequent cycles can be ascribed to the formationo fa nS EI layer. [40,41] The cathodic peak at approximately 0.23 Vr esults from alloyingo fL i x Si, and the anodic peak at approximately 0.5 Vi sr elated to dealloying of Li x Si. [42,43] Moreover,t hese peaks become stronger in the subsequents cans because of the activation process of the active materials and transformation of crystalline Si into the amorphousp hase during the charge/discharge process.…”

Silicon Anodes for High‐Performance Storage Devices: Structural Design, Material Compounding, Advances in Electrolytes and Binders

“…Highly porous carbon‐coated Si (cpSi@C) nanoparticles as anode materials for LIBs exhibited stable electrochemical performance . An Si/SiO 2 ‐ordered‐mesoporous carbon (Si/SiO 2 −OMC) nano composite displayed superior reversible capacity (958 mAh g −1 at 0.2 A g −1 after 100 cycles) . In addition, the large specific surface area and pore area of the metal‐organic framework can effectively absorb the electrolyte, and provide a faster diffusion channel for lithium ions to improve the rate performance .…”

Carbon‐Based Alloy‐Type Composite Anode Materials toward Sodium‐Ion Batteries

“…Nevertheless, some encouraging work is beginning to crop up in recent years, shining a light on the utilization of Si/C anodes in SIBs. As a representative example, Zeng et al prepared ternary phased Si/SiO 2 ‐ordered‐mesoporous‐carbon (OMC) architecture, in which crystal Si nanoparticles and amorphous SiO 2 homogeneously were enveloped into the OMC. This ternary anode maintained a large reversible capacity of 190 mAh g −1 even after 500 cycles at 1000 mA g −1 .…”