Eco-friendly synthesis of SiO2 nanoparticles confined in hard carbon: A promising material with unexpected mechanism for Li-ion batteries

Abstract

A fast, simple and environmentally friendly one-pot route to obtain carbon/SiO 2 hybrid materials is reported in this work. This consists in simple mixture of carbon and silica precursors, followed by thermal annealing at different temperatures. An interpenetrating hybrid network composed of hard carbon and amorphous SiO 2 nanoparticles (2e5 nm) homogeneously distributed was achieved. Increasing the annealing temperature from 600 C up to 1200 C, the material porosity and oxygen functional groups are gradually removed, while the amorphous nature of SiO 2 is conserved. This allows to diminish the irreversible capacity during the first charge-discharge cycle and to increase the reversible capacity. An excellent cycling capability, with a reversible capacity up to 535 mA hg-1 at C/5 constant current rate was obtained for C/SiO 2 materials used as anodes for Li-ion batteries. An atypical increase of the capacity during the first 50 cycles followed by a stable plateau up to 250 cycles was observed and related to electrolyte wettability limitation through the materials, particularly for those annealed at high temperatures which are more hydrophobic, less porous and the SiO 2 nanoparticles less accessible. The SiO 2 lithiation mechanism was evaluated by XRD, TEM and XPS post-mortem analyses and revealed the formation of reversible lithium silicate phases.

Link between Alkali Metals in Salt Templates and in Electrolytes for Improved Carbon-Based Electrochemical Capacitors

“…The Raman analyses for powders and electrode materials were performed at room temperature in a backscattering geometry using a LabRAM BX40 (Horiba Jobin Yvon) microspectrometer equipped with a He-Ne excitation source (wavelength of 532 nm). 46 The textural properties of the carbon powders and carbon-based electrodes were evaluated using N 2 and CO 2 adsorption isotherms. The N 2 adsorption/desorption isotherms for powders were measured with a Micromeritics ASAP 2020 device at 77 K. The powder samples were outgassed in vacuum at 300 °C for 12 h before the adsorption analysis.…”

Microsphere‐Like SiO2/MXene Hybrid Material Enabling High Performance Anode for Lithium Ion Batteries

“…To address these challenges, various volume buffering substrates with excellent conductivity have been employed to blend with SiO 2 material . Among them, introduction of carbon is proved to be an effective strategy to enhance the cycling stability of SiO 2 ‐based anode . Chen's group has fabricated SiO 2 /carbon composite nanospheres, which present a stable capacity of about 620 mA h g −1 after 300 cycles .…”

“…Chen's group has fabricated SiO 2 /carbon composite nanospheres, which present a stable capacity of about 620 mA h g −1 after 300 cycles . Ghimbeu et al have designed an interpenetrating hybrid network composed of hard carbon and amorphous SiO 2 nanoparticles with a reversible capacity up to 535 mA h g −1 at C/5 constant current rate . Besides, metals can also be used to couple with SiO 2 material to boost the electronic conductivity and the electrochemical activity .…”

Valorizing low cost and renewable lignin as hard carbon for Na-ion batteries: Impact of lignin grade

“…The C1s spectra for LS-HC (Figure 5a) present an important contribution at 284.5 eV coming from the Csp 2 . The associated oxygen-containing functional groups, ie., ether (C-OR), carbonyl (C=O) and carbon bonded to carbonyl groups (C-C=O), are observed in significant less extent between 284-289 eV[28]. Another important peak is seen at 286.8 eV and associated to C-C bonds due to the adventitious carbon[29].…”