Carbon-Coated Si Nanoparticles Anchored on Three-Dimensional Carbon Nanotube Matrix for High-Energy Stable Lithium-Ion Batteries

Abstract

An easy and scalable synthetic route was proposed for synthesis of a high-energy stable anode material composed of carbon-coated Si nanoparticles (NPs, 80 nm) confined in a three-dimensional (3D) network-structured conductive carbon nanotube (CNT) matrix (Si/CNT@C). The Si/CNT@C composite was fabricated via in situ polymerization of resorcinol formaldehyde (RF) resin in the co-existence of Si NPs and CNTs, followed by carbonization at 700 °C. The RF resin-derived carbon shell (~10 nm) was wrapped on the Si NPs and CNTs surface, welding the Si NPs to the sidewall of the interconnected CNTs matrix to avoid Si NP agglomeration. The unique 3D architecture provides a highway for Li+ ion diffusion and electron transportation to allow the fast lithiation/delithiation of the Si NPs; buffers the volume fluctuation of Si NPs; and stabilizes solid–electrolyte interphase film. As expected, the obtained Si/CNT@C hybrid exhibited excellent lithium storage performances. An initial discharge capacity of 1925 mAh g−1 was achieved at 0.1 A g−1 and retained as 1106 mAh g−1 after 200 cycles at 0.1 A g−1. The reversible capacity was retained at 827 mAh g−1 when the current density was increased to 1 A g−1. The Si/CNT@C possessed a high Si content of 62.8 wt%, facilitating its commercial application. Accordingly, this work provides a promising exploration of Si-based anode materials for high-energy stable lithium-ion batteries.

The Utilization of Carbon Nanotubes in Advanced Silicon – Carbon Anode Materials for Lithium-Ion Batteries

“…Even at an increased current density of 1 Ag −1 , a reversible capacity of 827 mAhg −1 was retained, owing to its high silicon content of 62.8 wt%. This study presents a promising approach for utilizing silicon-based anode materials in high-energy stable LIBs [19]. Similarly, in related research, hybridizing nano-sized silicon with carbon-based nanostructures such as CNTs, carbon frameworks, and graphene has been shown to enhance cycling performance and rate capability.…”

Hybrid Ionically Covalently Cross-Linked Network Binder for High-Performance Silicon Anodes in Lithium-Ion Batteries

“…A covalently cross-linked network is effective in suppressing the initial cycle volume expansion of Si. However, as the number of cycles increases, the covalent bonds gradually break and fail to form new covalent bonds, resulting in the failure of the volume suppression effect of the 3D network at later cycling [45]. Out of all the tested samples, Si/CMC-HBPEI-80 exhibits the most favorable cycling performance, maintaining a specific capacity of 1545 mAh g −1 even after 300 cycles (as shown in Figure 8b).…”

Synthesis strategies of smart 3D nanoarchitectures and their applications in energy storage and conversion

“…At a current density of 0.1 A g −1 , a 1925 mAh g −1 initial discharge capacity has been attained, and after 200 cycles at this same current, the capacity remained at 1106 mAh g −1 . This Si/CNT@C has shown a significant 62.8 wt% Si content, which facilitates commercialized use 85 . In another study, by using an easy method of template removal and electrospinning, a unique free‐standing Si/C anode made of CNFs and yolk (Si)‐shell nanoparticles (referred to as Si@void@C/CNFs) has been created.…”

“…This Si/CNT@C has shown a significant 62.8 wt% Si content, which facilitates commercialized use. 85 In another study, by using an easy method of template removal and electrospinning, a unique free-standing Si/C anode made of CNFs and yolk (Si)-shell nanoparticles (referred to as Si@void@C/CNFs) has been created. In addition to ensuring structural integrity, the interlaced CNFs and tailored yolk-shell structure assist in buffering the volume increase of silicon during charge/discharge cycles.…”