A high-performance silicon/carbon composite as anode material for lithium ion batteries

Abstract

To overcome the existing rapid capacity decay, low conductivity and the expands and contracts in volume of Si/C composite anodes in lithium ion batteries, we have developed a silicon/carbon composite by spray drying and twice organic carbon source cladding process. The samples are characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectrometer, thermogravimetric analysis and x-ray photoelectron spectra (XPS). The electrochemical performance are analyzed by half-cell and full-cell experiments. The results show that the silicon/carbon composite is core–shell structure with the silicon embedded graphite as core and organic carbon layers as the shell, the particle size range from 8 μm to 24 μm. The first reversible capacity and initial coulombic efficiency of the silicon/carbon composite are 936.4 mAh g−1 and 88.6% in half-cell. The silicon/carbon composite exhibits a high capacity retention up to 80% after 680 cycles in full-cell, indicating an excellent cycling stability. The structure is beneficial to control volume expansion, improve conductivity and electrochemical performance.

Carbon–based Materials for Li‐ion Battery

“…[308][309][310][311][312][313][314][315] The blending of silicon with various carbonaceous materials is one of the effective strategies to overcome the above-mentioned issues and improve its overall electrochemical performance. [243,297,[316][317][318][319][320][321][322][323] To illustrate, the boron-doped nano/ microstructured silicon carbon nanotube composite with graphite framework (BÀ Si/CNT@G) developed by PÀ Li et al [324] exhibited excellent capacity retention of 84 % after 100 cycles with an ultrahigh active mass loading of 11.2 mg cm À 2 , which is outstripping the commercial active mass loading of graphite. Besides, the full cell LIBs fabricated with 2 mol % Al-doped fullconcentration-gradient Li[Ni 0.76 Co 0.09 Mn 0.15 ]O 2 (Al2-FCG76) display a higher areal energy density of 8.0 mWh cm À 2 even with a higher cathodic mass loading of 12.0 mg cm À 2 and exhibit excellent capacitive retention (~82.5 %) over 300 cycles (Figure 7a).…”

Strategies for Controlling or Releasing the Influence Due to the Volume Expansion of Silicon inside Si−C Composite Anode for High-Performance Lithium-Ion Batteries

“…Therefore, it was necessary to achieve the controllable fabrication of yolk shell structures by removing the template without etching. For example, Si/C [169], HSiNTs/CC [170], SiNPs@C [171], and Si/C [172] had unique hollow structures with sufficient space to alleviate the volume expansion of silicon and facilitate electron-ion transport, enhancing the rate capability and cycle life of LIBs [173,174]. Mi et al successfully prepared an Si@void@C composite material by using polyethyleneimine (PEI) as a sacrificial template to form the cavity (Figure 6d) [175].…”

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.…”