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Article  |  Open Access  |  13 May 2024

Modulation of physical and chemical connections between SiOx and carbon for high-performance lithium-ion batteries

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Energy Mater 2024;4:400043.
10.20517/energymater.2023.102 |  © The Author(s) 2024.
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SiOx is an encouraging anode material for high-energy lithium-ion batteries owing to the following unique characteristics: a relatively high theoretical capacity, low operating potential, ample resource availability, and, most importantly, lower volume changes compared to Si. However, its utilization has been hindered by a significant ~200% volume change during lithiation and low conductivity, leading to the breakdown of anode materials and accelerated capacity degradation. This study presents a novel SiOx/G/C composite comprising SiOx nanoparticles, graphite, and carbon nanotubes fabricated through a simple ball milling and annealing process. This composite features a dual-carbon framework interconnected with SiOx via C–O–Si bonds, enhancing reaction kinetics and accommodating volume fluctuations. These enhancements translate into remarkable advancements in cycling stability and rate performance. Specifically, as-prepared SiOx/G/C exhibits a high capacity retention of ~700 mAh·g-1 over 500 charging/discharging times at 1.0 A·g-1. Furthermore, when incorporated into a full-cell configuration (SiOx/G/C//LiNi1/3Co1/3Mn1/3O2), this system demonstrates a reversible capacity of 113 mAh·g-1 over 100 cycles at 1.0 mA·cm-2, underscoring its practical viability.


SiOx anode, lithium-ion batteries, silicon-carbon composite, dual-carbon engineering, chemical binding


Lithium-ion batteries (LIBs) have become ubiquitous in portable electronic equipment, electric vehicles, and smart grids[1-3]. However, the slow advancement in their energy density poses a challenge to meeting the demands of rapidly evolving energy storage applications. It is imperative to focus on developing advanced anode materials to tackle this challenge, especially if enhancing existing cathode materials proves difficult[4,5]. The SiOx (0 < x < 2) anode has several advantages. First, SiOx has a high theoretical specific capacity, such as ~1,900 mAh·g-1 for SiO2 and ~2,700 mAh·g-1 for SiO, facilitating the realization of high-energy-density LIBs[6,7]. Second, it is abundant and can be readily prepared on a large scale from agricultural waste[8]. Lastly, SiOx-based anodes generate Li2O and Li silicate during cycling, ensuring greater cycling stability than Si-based anode materials[9-10]. However, SiOx experiences a volumetric change of 200% during lithiation, leading to anode material breakdown and rapid capacity deterioration[11,12]. Furthermore, it exhibits low conductivity, approximately 6.7 × 10-4 S·cm-1, leading to poor rate capability. SiOx-carbon composites have been proposed to mitigate these significant challenges. These composites demonstrate promising electrochemical performance, leveraging the superior electronic conductivity and superior mechanical properties of carbon materials[13-15].

Carbon nanotubes (CNTs) are highly conductive and remarkably elastic. They are widely used to address SiOx-related challenges[16]. However, given their one-dimensional (1D) nature, CNTs often require support from other carbon materials when paired with SiOx. Alternatively, two-dimensional (2D) graphene or three-dimensional (3D) graphite are viable alternatives[17,18]. For example, SiOx-graphite composites have been recognized as encouraging candidates for high-performance LIBs, benefiting from enhanced capacity and conductivity of graphite. Nevertheless, the unique alloying-intercalation mechanism inherent in SiOx-graphite anodes presents significant obstacles, including volume fluctuations and an unstable solid-electrolyte interface. Graphene, derived from graphite, is an excellent support material for high-performance SiOx anodes in LIBs because it can mitigate volume changes, shorten lithium-ion transmission pathways, and increase conductivity[19]. However, differences in morphology between 0D SiOx particles and 1D CNTs or 3D graphite/2D graphene pose challenges in achieving robust interface adhesion between SiOx and carbon. The weak interfacial interaction forces between SiOx and carbon impede effective interfacial electron transfer and structural stability within the carbon network. A potential solution is to establish chemical bonds with active materials, thereby fostering a cohesive structure that enhances the high specific capacity of SiOx while preventing their displacement[20]. Addressing this challenge entails creating a 3D carbon network through chemical bonding, incorporating multiple carbon dimensions. However, identifying a preparation strategy that is both scalable and highly efficient for this approach remains challenging[21].

This study introduces a conductive dual-carbon network consisting of 1D CNTs and 3D graphite, chemically bonded with SiOx via C–O–Si linkages, facilitated by high-energy ball milling. This network was devised to enhance the electrochemical capabilities of 0D SiOx nanoparticles. The synergistic effect of CNTs and graphite was shown through control groups wherein SiOx was mixed solely with CNTs (SiOx/C) or graphite (SiOx/G). Fourier transform infrared spectroscopy (FTIR) analyses confirmed the formation of C–O–Si bonds, which agreed well with those results in X-ray photoelectron spectroscopy (XPS), validating their role in improving the electrochemical properties of SiOx/G/C electrodes. The dual-carbon network enveloped SiOx, reducing volume fluctuations and establishing efficient pathways for lithium transport. Consequently, SiOx supported by this dual-carbon interaction (SiOx/G/C) exhibited enhanced cycling performances and superior rate capability.


Preparation of SiOx/G/C, SiOx/G, and SiOx/C

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-1. After milling, the mixed product was annealed for 3 h at 900 °C in an Ar atmosphere and cooled naturally to create the SiOx/G/C composite. To compare, the control groups of SiOx/C and SiOx/G were prepared using the same process as SiOx/G/C but without introducing CNTs and graphite, respectively.

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 SiOx/G/C electrode, a lithium metal counter electrode, and a separator (Celgard 2400 type) were 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 SiOx/G/C (70 wt%), conductive carbon black (20 wt%), and cellulose sodium (10 wt%) dispersed in deionized (DI) water. After drying and punching, we obtained 1.2 cm wafers of the SiOx/G/C electrode with an average mass loading of 1.2 mg·cm-2. To assemble full cells, a prelithiated SiOx/G/C anode, LiNi1/3Co1/3Mn1/3O2 (NCM111) cathode, and Celgard 2400 separator 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 LiNi0.3Co0.3Mn0.3O2 (80 wt%), conductive carbon black (20 wt%), and polyvinylidene fluoride (10 wt%). Both half and full cells used 1.0 mol·L-1 LiPF6 in ethylene carbonate/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 SiOx/G/C 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.


The preparation process of the SiOx/G/C composite, depicted in Figure 1A, involves ball milling and 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 SiOx/G/C product. TEM and SEM photos of the SiOx/G/C composite (presented in Figure 1B and C, respectively) confirm the uniform wrapping of SiOx nanoparticles within a network of conductive carbon. Energy dispersive X-ray spectroscopy mapping shown in Supplementary Figure 1 reveals the uniformity of the SiOx/G/C composite. This close contact between SiOx and the dual-carbon network buffers volume changes during cycling and enhances electron transport pathways for the SiOx/G/C. HRTEM images of SiOx/G/C in Supplementary Figure 2A confirm the crystalline structure of CNTs and graphite [Supplementary Figure 2B] and the amorphous structure of SiOx [Supplementary Figure 2C]. Furthermore, SiOx particle sizes, determined to be less than 500 nm, confirm the efficiency of the ball milling method. The lattice fringes of graphite in SiOx/G/C, corresponding to (002) planes, were calculated to be approximately 0.33 nm. However, the TEM image of SiOx/G [Figure 1D] illustrates inadequate attachment of SiOx particles to graphite sheets, even after sonication, indicating the potential for CNTs to assist in exfoliating graphite. Additionally, SEM images of SiOx/G [Figure 1E] confirm that graphite alone is insufficient for rapidly forming a carbon network and embedding SiOx. The TEM [Figure 1F] and SEM images [Figure 1G] of the SiOx/C composite demonstrate efficacy of CNTs in preventing SiOx nanoparticle aggregation. However, owing to their 1D morphology, SiOx particles in the SiOx/C composite are more exposed than those in the SiOx/G/C sample. From the abovementioned results, creating a robust framework to stabilize SiOx with just one type of carbon material is challenging. However, leveraging the advantages of 3D graphite and 1D CNTs makes uniform dispersion of SiOx within a dual-carbon network achievable. This approach ensures structural stability and prevents electrical contact loss during cycling.

Modulation of physical and chemical connections between SiO<sub>x</sub> and carbon for high-performance lithium-ion batteries

Figure 1. (A) Preparation strategy of SiOx/G/C composite; (B) TEM image and (C) SEM image of SiOx/G/C; (D) TEM photo and (E) SEM photo of SiOx/G composite; (F) TEM image and (G) SEM imageof SiOx/C composite. CNT: Carbon nanotube; TEM: transmission electron microscopy; SEM: scanning electron microscopy.

To examine the structure and components of the SiOx/G/C, SiOx/G, and SiOx/C composites, different techniques, including XRD, Raman, FTIR spectroscopy, and XPS, were employed. XRD analysis [Figure 2A] elucidated the structural characteristics of the three composites mentioned earlier. Peaks observed at 26.6°, 44.6°, 54.7°, and 77.5° were identified as the diffraction planes of (002), (101), (004), and (110) for graphite (JCPDS no. 04-0836)[22], respectively. The characteristic graphite peak at 26.6° observed in SiOx/G also appeared in SiOx/G/C. Peaks at 26.4° and 44.7° (SiOx/C) relatively weaker than graphite in SiOx/G/C and SiOx/G composites corresponded to the (003) and (101) diffraction planes, indicating the presence of CNTs[23,24]. Additionally, a broad diffraction peak around 22.3° was indexed to the amorphous SiOx[25] in SiOx/C. Raman spectra shown in Supplementary Figure 3 confirmed the low crystallinity SiOx with a broad peak at 459 cm-1[26], consistent with XRD data. The presence of carbonaceous materials in the three previously mentioned samples was confirmed by D and G bands at approximately 1,324 and 1,564 cm-1, respectively, [Figure 2B]. The intensity ratio of the D-and G-Raman peaks (ID/IG value) of SiOx/G/C composites of 0.34 suggested a high degree of graphitization, beneficial for the performances of SiOx-carbon anodes[27,28]. The FTIR spectrum [Figure 2C] exhibited two peaks in SiOx/G/C at 1,630 and 1,677 cm-1, corresponding to the C=O and C=C bonds, similar to those peaks observed in SiOx/C and SiOx/G, indicative of sp2 carbon hybridization[29]. Peaks located at 1,103, 808, and 470 cm-1 were attributed to bending and asymmetric stretching vibrations of SiOx[30]. Comparison of FTIR spectra between SiOx nanoparticles (derived from ball milling micro SiO) and SiOx/G/C [Supplementary Figure 4] confirmed the formation of C–O–Si bonds. The disappearance of the broad peak located at 3,435 cm-1, assigned to the vibration of the –OH bond in SiOx, in SiOx/G/C suggests that the -OH of SiOx might combine with the dual-carbon network to form C–O–Si covalent bonds. Si–O–Si bonds in SiOx and SiOx/G/C are located at 1,086 and 1,103 cm-1, respectively. The shift in these two peaks is attributed to the C–O–Si bond formation at 1,230 cm-1 in SiOx/G/C, consistent with previous reports[31]. XPS spectra of SiOx/G/C, SiOx/G, and SiOx/C are depicted in Figure 2D, with similar peaks around 533, 284, 155, and 104 cm-1 assigned to O 1s, C 1s, Si 2s, and Si 2p, respectively. Further insights into electronic structure of the SiOx/G/C composite were obtained from the O 1s, Si 2p, and C 1s XPS spectra, as shown in Figures 2E and F, and Supplementary Figure 5, respectively. The O 1s spectrum in Figure 2E contains three peaks corresponding to C–O–Si, C–O–C, and Si–O–Si bonds[32], confirming the effect of ball milling in promoting the formation of a C–O–Si bond in the SiOx/G/C. The Si 2p spectrum [Figure 2F] exhibits three peaks: Si–O (105.1 eV), Si–C (104.4 eV), and Si–Si (103.7 eV)[33]. Analysis of the C 1s spectrum [Supplementary Figure 5] reveals peaks at 285.1, 284.2, and 283.8 eV, attributed to C=O, C–O, and C–C/C=C bonds, respectively[34]. These findings confirm the creation of a chemical bond between SiOx and carbon, enhancing charge transfer and increasing structural stability. To accurately determine the relative ratios of SiOx in the SiOx/G/C composite, TGA results (SiOx/G/C) were conducted [Supplementary Figure 6], revealing a SiOx content of 72%.

Modulation of physical and chemical connections between SiO<sub>x</sub> and carbon for high-performance lithium-ion batteries

Figure 2. (A) XRD results, (B) Raman and (C) FTIR spectrum of SiOx/G/C, SiOx/G and SiOx/C composites; (D) XPS spectrum of SiOx/G/C, SiOx/G, and SiOx/C; SiOx/G/C’s XPS spectrum of (E) O 1s and (F) Si 2p. XRD: X-ray diffraction; FTIR: Fourier transform infrared spectroscopy; XPS: X-ray photoelectron spectroscopy.

The lithium storage performance of three types of anodes, namely SiOx/G/C, SiOx/G, and SiOx/C, was investigated to assess their efficacy of a dual-carbon network for SiOx. Figure 3A reveals CV curves of the SiOx/G/C anode for the initial five cycles, elucidating the charging and discharging reactions. The cathodic peaks observed at 0.01 and 0.17 V indicate alloy reactions between Li and Si, while the anodic peaks at 0.51, 0.18, and 0.33 V were attributed to the de-alloying of LixSi. The increasing CV area from the first to the fourth cycle suggests an activation process during cycling. Conversely, the remarkable similarity between the fourth and fifth curves implies the potential stability of the SiOx/G/C over several cycles[35,36].

Modulation of physical and chemical connections between SiO<sub>x</sub> and carbon for high-performance lithium-ion batteries

Figure 3. (A) CV curves and (B) voltage curves results of the SiOx/G/C electrode; (C) Rate capabilities of SiOx/G/C electrodes at different current densities compared with control groups; (D) SiOx/G/C’s charging and discharging voltage curves under different current densities; (E) SiOx/G/C’s cyclic capabilities at 1.5 A·g-1 compared with control groups; (F) Thick SiOx/G/C (~2.2 mg·cm-2) electrode’s cycling performance at 2.0 mA·cm-2; (G) SiOx/G/C’s long-term cycling performance of electrode at 1.0 A·g-1. CV: Cyclic voltammetry.

Figure 3B illustrated voltage curves of the SiOx/G/C anode about the first three charging/discharging cycles in the range from 0.01 to 1.5 V at a smaller current density of 0.1 A·g-1. It delivers high initial discharging/charging capacities of 2,617/1,674 mAh·g-1, respectively, delivering an unsatisfactory initial coulombic efficiency (ICE) of 64%. The phenomenon is attributed to irreversible formation of Li2O and lithium silicates, which could potentially be addressed by prelithiation technology[37].

Discharging capacities of SiOx/G/C acquired by changing current densities are presented in Figure 3C and D, showcasing its superior rate capabilities compared to SiOx/C and SiOx/G. The discharging capacity of SiOx/G/C was 1,482 mAh·g-1 when working at a current density of 0.5 A·g-1. While at 6.0 A·g-1, it maintains a better capacity (347 mAh·g-1), surpassing those common results of SiOx/G and SiOx/C when performed at equivalent current densities. Remarkably, after 100 cycles of comparison, with the current density reverting to 1.0 A·g-1, the discharge capacity of SiOx/G/C recovers to 855 mAh·g-1, indicating satisfactory rate capability. The initial ICE was verified through the voltage variations of SiOx/G and SiOx/C (Supplementary Figures 7 and 8, respectively) at 0.1 A·g-1 for the first charging or discharging time. Consequently, SiOx/G and SiOx/C demonstrated ICE values of 62.0% and 64.9%, respectively, indicating minimal changes in ICE despite the construction of the carbon network. Superior performance of the SiOx/G/C anode is attributed to reinforced electronic/ionic conductivity and surface passivation facilitated by the dual-carbon network.

Figure 3E depicts the cycling performance of three electrode types: SiOx/G/C, SiOx/G, and SiOx/C. Notably, SiOx/G/C outperforms control groups at 1.5 A·g-1, sustaining an encouraging capacity of 675 mAh·g-1 over 300 cycles. This highlights the pivotal role of the dual-carbon network in enhancing the Li+ storage performance of SiOx/G/C as an anodic material compared to control groups. Moreover, a high areal capacity of the SiOx/G/C electrode, acquired at 2.0 mA·cm-2, of 1.67 mAh·cm-2 exhibits consistent capacity retention over 100 cycles, even loaded about 2.2 mg·cm-2 [Figure 3F], underscoring its promising potential for practical application. Long-term cycling performance of SiOx/G/C [Figure 3G] was demonstrated. Following activation (0.2 A·g-1) in the initial three cycles, SiOx/G/C underwent cycling at 1.0 A·g-1 for 500 cycles, delivering a noteworthy lithium storage of approximately 700 mAh·g-1 with a capacity retention of 78% (compared to the fourth cycle, 898 mAh·g-1). This performance surpasses that of many recently reported SiOx-based anodes for LIBs [Supplementary Table 1][18,21,25,38-43].

The electrical resistivities of SiOx/G/C, SiOx/C, and SiOx/G samples were analyzed to discern differences in the conductive mechanism [Figure 4A]. The detailed electrical resistivity data of SiOx/G/C are provided in Supplementary Table 2. Results indicated that SiOx/C and SiOx/G exhibited higher electrical resistivities of 0.129 and 0.151 Ω·cm, respectively, compared to 0.075 Ω·cm for SiOx/G/C. Enhanced electrical conductivity of SiOx/G/C can be attributed to as-prepared dual-carbon network, facilitating a higher electron transfer rate. Figure 4B shows the electrochemical mechanism of SiOx/G/C through CV data at varied scan rates ranging from 0.1 mV·s-1 to 1.0 mV·s-1. Notably, anodic (peak A) and cathodic peaks (peaks B and C) exhibit similar profiles as the sweep rates increase, indicating favorable reaction kinetics and minimal electrode polarization. Further insights into the diffusion-controlled and capacitive-controlled mechanisms of the SiOx/G/C anode were obtained by analyzing the relationship between peak current (i) and scan rate (v), denoted as[44]:

$$ i=a v^{b} $$

$$ \log i=b \log v+\log a $$

Modulation of physical and chemical connections between SiO<sub>x</sub> and carbon for high-performance lithium-ion batteries

Figure 4. (A) Electrical resistivities of the SiOx/G/C and other two samples; (B) CV data of the SiOx/G/C at changing scan rates; (C) Fitted lines and corresponding b-value resulted from the value of log(i, peak current) vs. log(v, scan rate) for SiOx/G/C electrode; (D) Contribution of capacitive charge storage to the total capacity of SiOx/G/C at a higher scan rate (1.0 mV·s-1); (E) Two kinds of charge storage distribution ratios with the same scan rates; (F) The relationships of Z’ and ω-1/2 for the SiOx/G/C and the other two control groups. CV: Cyclic voltammetry.

After analyzing and fitting the data for peaks A, B, and C, the b-values for each peak are illustrated in Figure 4C. Peak B exhibits a b-value of 0.48, closely approaching 0.5, indicative of a diffusion-controlled process. Conversely, peaks A and C have estimated b-values of 0.85 and 0.63, respectively, suggesting a mixed storage mechanism with a dominance of the capacitive mechanism. This hybrid mechanism combines the high capacity of SiOx with the cyclic stability of the dual-carbon network, resulting in satisfactory performance. Furthermore, the ratio of the capacitive contribution in the hybrid mechanism was determined by[45]:

$$ i=k_{1} v+k_{2} v^{1 / 2} $$

After calculating the values of k1 and k2, we confirmed the capacitive- and diffusion-controlled ratios. For instance, at scan rates of 1.0 and 0.1 mV·s-1, 67% and 40% of the capacitive-controlled ratios were calculated, respectively [Figures 4D and Supplementary Figure 9]. Furthermore, the capacitive-controlled ratio [Figure 4E] was determined under the same scan rates as those in Figure 4B, revealing an increasing proportion of capacitive contribution with increasing scan rates, which is advantageous for high-rate charging or discharging. The enhanced reaction kinetics of SiOx/G/C compared with the control groups was investigated using the EIS test [Supplementary Figure 10]. Detailed parameters of EIS [Supplementary Table 3] and the equivalent circuit [Supplementary Figure 11] were analyzed and fitted, with the SiOx/G/C anode exhibiting lower resistance than the control groups. This can be attributed to the unique dual-carbon network comprising graphite and CNTs. Furthermore, the lithium-ion diffusion coefficient for SiOx/G/C and the control groups was calculated by[33]:

$$ D_{\mathrm{Li}^{+}}=0.5\left(\frac{R T}{A F^{2} \sigma C}\right)^{2} $$

Where R (gas constant), F (Faraday constant) and T (absolute temperature) remain constant. Surface area of the electrode, labeled as A, could result from the as-prepared electrode, and molar concentration of Li+, named C in Equation (4), could be calculated by the electrolyte, with the σ-value determining the $$ D_{Li^{+}} $$ for SiOx/G/C and other two electrodes. By establishing the connection between Z’ and ω-1/2 in low-frequency part of EIS, the σ-values could be fitted and correlated to the slopes of the lines in Figure 4F, calculated using[33]:

$$ Z^{\prime}=R_{D}+R_{L}+\sigma \omega^{-1 / 2} $$

The minimum σ-value observed for SiOx/G/C indicates the superior Li+ diffusion coefficient, aligning well with the cyclic performance and rate capability demonstrated in Figure 3.

To assess the application potential of the SiOx/G/C, it is paired with a NCM111 cathode [Figure 5A]. In the first step, SiOx/G/C was combined with lithium foil and cycled multiple times until the coulombic efficiency (CE) of the half-cell reached 99%. This step aimed to minimize initial lithium loss in full cells. Subsequently, the delithiated SiOx/G/C anode was paired with the NCM111 cathode, and the setup was cycled at 0.2 mA·cm-2 for the first two cycles, followed by 1.0 mA·cm-2 for subsequent cycles. The voltage curves of a SiOx/G/C//NCM111 full cell during charging and discharging at 2.8-4.2 V are depicted in Figure 5B. The cell exhibits initial charging/discharging capacities of 275.2 and 201.8 mAh·g-1, respectively, delivering an ICE of 73%. Its cyclic performance is presented in Figure 5C, demonstrating satisfactory lithium storage of 116 mAh·g-1 over 100 cycles. These results underscore the exceptional performance of SiOx/G/C in full cells.

Modulation of physical and chemical connections between SiO<sub>x</sub> and carbon for high-performance lithium-ion batteries

Figure 5. (A) Design of the SiOx/G/C//NCM111 full cell; (B) Charging/discharging voltage profiles; (C) Cyclic performances of SiOx/G/C//NCM111 full cell at 1.0 mA·cm-2.


In summary, to address the challenges of high volume variation and slow reaction dynamics associated with SiOx anodes, we devised a dual-carbon network utilizing 3D graphite and 1D CNTs through a straightforward and highly effective ball milling and annealing process. This novel dual-carbon network, possessing strong electrical connections to SiOx nanoparticles via C–O–Si bonds, mitigated the volume variation of SiOx and facilitated smooth Li+ transport, ensuring the retention of high capacity advantages of SiOx-based anodes. Leveraging the benefits of this chemically bound dual-carbon network, both Li//SiOx/G/C half cells and SiOx/G/C//NCM111 full cells demonstrated remarkable performance, delivering an encouraging lithium storage of ~700 mAh·g-1 over 500 cycles and 116 mAh·g-1 for 100 cycles. These results underscore the considerable potential of our approach, offering both scalable preparation and performance enhancement for high-energy storage materials.


Authors’ contributions

Conceptualization, methodology, investigation, writing - original draft: Zhang K

Formal analysis, investigation, data curation: Xing J

Formal analysis: Peng H

Resources: Gao J

Investigation, data curation: Ai S

Visualization: Zhou Q

Resources, supervision: Yang D

Methodology, supervision, writing - review and draft: Gu X

Availability of data and materials

The datasets generated or analyzed during this study are available from the corresponding authors upon reasonable request.

Financial support and sponsorship

The authors thank the Natural Science Foundation of Shandong Province (Nos. ZR2022QB182, ZR2022MB088) and the National Natural Science Foundation of China (No. 22378426).

Conflicts of interest

All authors declared that there are no conflicts of interest.

Ethical approval and consent to participate

Not applicable.

Consent for publication

Not applicable.


© The Author(s) 2024.

Supplementary Materials


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Zhang K, Xing J, Peng H, Gao J, Ai S, Zhou Q, Yang D, Gu X. Modulation of physical and chemical connections between SiOx and carbon for high-performance lithium-ion batteries. Energy Mater 2024;4:400043.

AMA Style

Zhang K, Xing J, Peng H, Gao J, Ai S, Zhou Q, Yang D, Gu X. Modulation of physical and chemical connections between SiOx and carbon for high-performance lithium-ion batteries. Energy Materials. 2024; 4(2): 400043.

Chicago/Turabian Style

Zhang, Kaiyuan, Jiarui Xing, Huili Peng, Jichao Gao, Shuheng Ai, Qiwang Zhou, Di Yang, Xin Gu. 2024. "Modulation of physical and chemical connections between SiOx and carbon for high-performance lithium-ion batteries" Energy Materials. 4, no.2: 400043.

ACS Style

Zhang, K.; Xing J.; Peng H.; Gao J.; Ai S.; Zhou Q.; Yang D.; Gu X. Modulation of physical and chemical connections between SiOx and carbon for high-performance lithium-ion batteries. Energy Mater. 2024, 4, 400043.

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