Optimized Porous Si/SiC Composite Spheres as High‐Performance Anode Material for Lithium‐Ion Batteries

Abstract

Fabricating porous Si via magnesiothermic reduction is an effective way to tackle the volume expansion of Si anodes. However, the agglomeration of Si due to the local heat accumulation during the thermal reduction process severely limits its lithium storage capacity. Here, we propose a simple approach to synthesize optimized porous Si/SiC composite (pSi/SiC) spheres via modifying the precursor SiO2 of magnesiothermic reduction. After heat treatment process, in‐situ generated SiC uniformly dispersed among silicon nanoparticles, playing a crucial role in decreasing local heat accumulation, sequentially maintaining the stability of the porous spherical structure. This method not only optimized pore distribution of porous Si, but also enhanced the buffer effect of SiC. Finally, the as‐prepared pSi/SiC exhibits superior lithium storage performance (1653.4 mAh g−1 and 1446.7 mAh g−1 at 0.5 A g−1 and 1 A g−1 after 100 cycles, 1022 mAh g−1 at 2 A g−1 after 400 cycles, and 420 mAh g−1 at 5 A g−1 even after 2000 cycles). This work can provide an inspirational idea to prepare other optimized porous Si‐based anode materials through introducing various buffer materials.

Computer Test of a New Silicene Anode for Lithium‐Ion Batteries

“…Recently, considerable efforts have been made in the search for materials for an efficient anode of lithium ion batteries of a new generation, [19][20][21][22][23][24] including optimized porous Si-based anode materials, [22] anode materials in a flexible version, [23] and the use of silicide electrodes using a liquid electrolyte. In the anode structure under consideration during charging the lithium ions fit into the gaps between the silicene sheets-a process known as intercalation.…”

“…LiPON, lithium phosphorus oxynitride, is an amorphous glassy material that can be used as an electrolyte material in thin film lithiumion batteries. Recently, considerable efforts have been made in the search for materials for an efficient anode of lithium ion batteries of a new generation, [19][20][21][22][23][24] including optimized porous Si-based anode materials, [22] anode materials in a flexible version, [23] and the use of silicide electrodes using a liquid electrolyte. [24] A distinctive feature of this work is the study of the functioning of a thin-film silicon anode at the atomic level.…”

Flexible Carbon Nanotubes Confined Yolk-Shelled Silicon-Based Anode with Superior Conductivity for Lithium Storage

“…Figure 3 a–c shows the transmission electron microscopy (TEM) images of homemade SiO 2 and reduced Si NPs. The high-resolution TEM image (HRTEM), taken from one of the Si NPs, reveals that the obtained Si NPs had high crystallinity [ 49 , 50 ]. The TEM images of Si@RF and Si@RF@SiO 2 , as shown in Figure 3 d–e, confirm that the Si NPs were well wrapped by the RF carbon-SiO 2 double coating layers.…”

Advanced Materials Prepared via Metallic Reduction Reactions for Electrochemical Energy Storage

“…[ 27 ] Porous Si with less agglomeration can be obtained by employing modified SiO 2 as precursors via Mg reduction. [ 28 ] The versatile micro‐/nanostructures of porous materials can make them more applicative to various scenarios. Generally, compared with other methods, MRRs can easily produce and regulate porous structured materials without introducing extra encapsulation procedures or pore‐forming process.…”