Page 30 - Read Online

Zhang et al. Energy Mater 2024;4:400043 https://dx.doi.org/10.20517/energymater.2023.102 Page 3 of 12

EXPERIMENTAL
Preparation of SiO /G/C, SiO /G, and SiO /C
x
x
x
The materials used in the experiment were SiO (99.99% metal basis) from Aladdin, graphite (AR) from
Macklin, and CNTs from Aladdin. They were used as is, without any further purification. The experiment
involved adding 0.3 g of micro SiO, 60 mg of graphite, and 60 mg of CNTs to a 50 mL agate jar containing
10 g of agate balls, which was performed in the Ar-filled glove box. The jar was then sealed and transferred
to a ball milling machine. The mixture was milled for 24 h at the rotation speed of 600 r·min . After milling,
-1
the mixed product was annealed for 3 h at 900 °C in an Ar atmosphere and cooled naturally to create the
SiO /G/C composite. To compare, the control groups of SiO /C and SiO /G were prepared using the same
x
x
x
process as SiO /G/C but without introducing CNTs and graphite, respectively.
x
Material characterization
The field-emission scanning electron microscope from Germany, the Zeiss Gemini 300 type, was used to get
scanning electron microscopy (SEM) photos, while a JEOL JEM 1011 transmission electron microscope
from Japan records transmission electron microscopy (TEM) images for this work. A JEOL JEM F200
transmission electron microscope from Japan records the High-resolution TEM (HRTEM) images. XPS
results and X-ray diffraction (XRD) data were collected from a Thermo Fischer ESCALAB 250 X-ray
photoelectron spectrometer (from the USA) and a Bruker D8 Advance X-ray diffractometer (from
Germany), respectively. In addition, Raman spectra and FTIR results were obtained from HORIBA
JYHR800 and Bruker Tensor 27 spectrometers from Japan and Germany, respectively. Thermal gravimetric
analysis (TGA) was collected by a Mettler Toledo TGA/SDTA851 thermal gravimetric analyzer from
Switzerland.

Electrochemical measurements
A SiO /G/C electrode, a lithium metal counter electrode, and a separator (Celgard 2400 type) were
x
assembled into coin cells (CR2032 type) in an argon-filled glovebox to fabricate half cells. On a Cu-foil
current collector, a slurry was coated, comprising as-prepared SiO /G/C (70 wt%), conductive carbon black
x
(20 wt%), and cellulose sodium (10 wt%) dispersed in deionized (DI) water. After drying and punching, we
obtained 1.2 cm wafers of the SiO /G/C electrode with an average mass loading of 1.2 mg·cm . To assemble
-2
x
full cells, a prelithiated SiO /G/C anode, LiNi Co Mn O (NCM111) cathode, and Celgard 2400 separator
1/3
1/3
2
x
1/3
were combined into CR2032 coin cells within an argon-filled glovebox. A nickel cobalt manganese (NCM)
cathode was prepared by pasting a slurry onto an Al foil. The N-methyl pyrrolidone was used to mix the
slurry, which contained commercial LiNi Co Mn O (80 wt%), conductive carbon black (20 wt%), and
0.3
0.3
0.3
2
-1
polyvinylidene fluoride (10 wt%). Both half and full cells used 1.0 mol·L LiPF in ethylene carbonate/
6
dimethyl carbonate (volume ratio, 1:1) with 7% fluoroethylene carbonate. We conducted galvanostatic
charging/discharging tests on both the half (0.01-1.5 V) and full cells worked at 2.8-4.2 V, using a battery
testing system (LAND CT2001A). Additionally, electrochemical impedance spectroscopy (EIS) of SiO /G/C
x
half cells was tested with a frequency range of 100 kHz to 0.01 Hz, and their cyclic voltammetry (CV) test
was working at a scan rate of 0.1-1.0 mV·s .
-1
RESULTS AND DISCUSSION
The preparation process of the SiO /G/C composite, depicted in Figure 1A, involves ball milling and
x
annealing. First, SiO, graphite, and CNTs were combined in a ball milling jar and sealed in an argon-filled
glovebox to prevent further oxidation of SiO. Through high-energy ball milling, the raw materials were
uniformly mixed and reduced by adjusting the number of agate balls with different sizes. Subsequently, the
annealing phase, conducted under an argon atmosphere at 900 °C, induced the disproportion reaction,
yielding the SiO /G/C product. TEM and SEM photos of the SiO /G/C composite (presented in Figure 1B
x
x
and C, respectively) confirm the uniform wrapping of SiO nanoparticles within a network of conductive
x