Si/SiO_x Nanoparticles Embedded in a Conductive and Durable Carbon Nanoflake Matrix as an Efficient Anode for Lithium‐Ion Batteries

Abstract

In this study, a route to synthesize a Si@SiO x /carbon nanoflake nanocomposite is proposed using ecological and polar solventsoluble ethyl cellulose as a promising new carbon source for obtaining silicon composites. Equal proportions of ethylcellulose and commercial nanosilicon powders are used to prepare the silicon/organic hybrid through an in situ chemical process, and the subsequent carbonization affords the Si@SiO x /C composite. The SiO x layer is partially formed using the employed method and air drying processes. As an anode electrode for lithium-ion batteries (LIBs), the composite provides excellent reversible capacity (1830 mAh g À 1 at 200 mA g À 1 after 60 cycles) with 92 % capacity retention and superior rate performance (1464 mAh g À 1 at 3.2 A g À 1). The electrode with a high mass loading of 3.42 mg cm À 2 delivered discharge capacities of 753 and 387 mAh g À 1 at high current densities of 2 A g À 1 and 4 A g À 1 , respectively. These results show that the coupling of silicon nanoparticles with an oxide layer and a conductive carbon framework is an effective design to retain the inherent properties of the silicon-based anode, exhibiting its potential for use as a low-cost anode for practical applications.

Rational Design and Performance of Ansode Materials Based on Si/SiOx/C Particles Anchored on Graphene Sheets

“…Both the Si/SiO x /C electrode and the Si/SiO x /C/Gr electrode have a similar potential profile in ∼0.1 V in the initial discharge curve, corresponding to the relevant generation of the Li–Si alloy and inter-reaction of Li + with SiO x . The as-obtained electrodes are first activated the two cycles at 0.1 A g –1 and then cycled 200 times at 0.3 A g –1 . The cycling stability of Si/SiO x /C or Si/SiO x /C/Gr anodes was tested at 0.01–2 V and is shown in Figure c.…”

Synthesis of Free‐Standing CoxP/Co3(PO4)2/C Composite Nanofiber Mats and Their Characteristics as Multi‐functional Interlayers for Lithium‐Sulfur Batteries

“…[38] Nevertheless, the I G /I D intensity ratios are still higher than 1.00, indicating good electrical conductivity of carbon. [39] As seen from the N 2 adsorption-desorption isotherms and pore-size distribution of the samples in Figure S2, the samples have similar isotherms with similar BET specific surface areas of about 290-340 m 2 g À 1 (Table 1). This result indicates that the samples of different compositions have a similar porous structure and surface area.…”

“…On the other hand, a slightly higher intensity of D‐band for the Co x P/Co 3 (PO 4 ) 2 /C can be ascribed to the surface functionalization with the formation of P‐doped carbon [38] . Nevertheless, the I G /I D intensity ratios are still higher than 1.00, indicating good electrical conductivity of carbon [39] . As seen from the N 2 adsorption‐desorption isotherms and pore‐size distribution of the samples in Figure S2, the samples have similar isotherms with similar BET specific surface areas of about 290–340 m 2 g −1 (Table 1).…”

Metal (Cu/Fe/Mn)-Doped Silicon/Graphite Composite as a Cost-Effective Anode for Li-Ion Batteries

“…Introducing carbon materials as composites with Si and using protective carbon coatings are also effective ways to improve the performance of Si anodes [ 21 , 22 , 23 ]. The amount of carbon in the composite material plays a crucial role in stabilizing the Si anode performance by affording the required electrical conductivity and mechanical stability [ 24 , 25 ]. However, adding large amounts of carbon significantly reduces the overall specific capacity of the composite material by forming a dead layer on the surface of the electrode.…”