Search Results (99)

Silicon-based anodes have emerged as promising candidates for advanced lithium-ion batteries (LIBs) owing to their outstanding lithium storage capacity; however, the commercial implementation of silicon-based anodes is hindered primarily by their significant volumetric changes and the resulting solid electrolyte interphase (SEI) instability during the lithiation/delithiation process. To overcome these issues, electrolyte optimization, particularly through the use of functional additives and solid-state electrolytes, has attracted significant research attention. In this paper, we review the recent developments in electrolyte additives, such as vinylene carbonate, fluoroethylene carbonate, and silane-based additives, and new additives, such as dimethylacetamide, that improve the SEI stability and overall electrochemical performance of silicon-based anodes. We also discuss the role of solid electrolytes, including oxides, sulfides, and polymer-based systems, in mitigating the volume changes in Si and improving safety. Such approaches can effectively enhance both the longevity and capacity retention of silicon-based anodes. Despite significant progress, further studies are essential to optimize electrolyte formulation and solve interfacial problems. Integrating these advances with improved electrode designs and anode materials is critical for realizing the full potential of silicon-based anodes in high-performance LIBs, particularly in electric vehicles and portable electronics. Full article

Sn-based anodes for lithium-ion batteries (LIBs) offer high capacity and low cost; however, significant volume changes during lithiation/delithiation cause mechanical degradation, limiting their practical applications. Microstructural control is a key approach to mitigating these volume changes. This study reports the fabrication of core (Sn rod)-shell (mesoporous Sn-oxide layer) structures through electrodeposition followed by anodization, and their applications to anode active materials for LIBs. First, micro-Sn rods with controlled lengths and diameters were fabricated under various electrodeposition conditions. The electrodeposited Sn exhibited a dendritic structure with short secondary rods branching from a long primary rod. While the primary Sn rod diameters remained constant, the secondary rod diameters varied depending on electrodeposition parameters. Notably, rod coarsening due to secondary rod agglomeration occurred at higher currents and longer deposition durations during galvanostatic electrodeposition. In contrast, potentiostatic electrodeposition prevented agglomeration and increased the quantity of Sn rods with voltage. Subsequently, the core-shell structures were fabricated by anodizing Sn rods, forming mesoporous Sn-oxide layers with different pore sizes and pore wall thicknesses. Electrochemical characterization revealed that the core-shell anode performance for LIBs varied with the Sn-oxide shell’s microstructure. These findings provide insights into optimal core-shell structures to improve anode performance for LIBs. Full article

We report a facile galvanic oxidation corrosion method for the preparation of cuprite nanocrystals (Cu₂O) with controllable oxygen vacancies. The Cu₂O microspheres have been employed as active anode materials in lithium-ion batteries (LIBs), exhibiting excellent electrochemical performance. The effect of oxygen vacancies on the electrochemical properties was studied. The oxygen vacancy-rich Cu₂O electrodes exhibited a high specific discharge capacity (1002.3 mAh g⁻¹ at 0.1 C) and remarkable reversibility. Oxygen vacancies in Cu₂O not only promote high electronic conductivity but also provide additional active sites for lithiation/delithiation, further enhancing electrochemical performance. Furthermore, the formation mechanism of Cu₂O during the galvanic oxidation–corrosion process has been proposed. Full article

All-solid-state lithium-ion batteries (ASSLBs) are attractive energy storage devices because of their excellent gravimetric and volumetric capacity and ability to supply high power rates. Porous silicon (Si) is a promising material for an anode in lithium-ion batteries due to its high capacity and low discharge potential. However, Si anodes cause significant problems due to strong volume growth during the lithiation and delithiation processes, which results in rapid capacity fading and poor cycle stability. To overcome this problem, we developed mesoporous silica (SiO₂) aerogels into porous silicon (Si) anodes using a magnesiothermic reduction (MTR) process. By effectively preserving the porous structure, this approach enables the material to endure volume fluctuations while maintaining its structural integrity during cycling. In our study, we demonstrated a feasible approach to fabricate the porous silicon (Si) from hydrophobic and hydrophilic silica (SiO₂) aerogel and magnesium powder (Mg) through the MTR process at 600~900 °C. The sample obtained after the reduction process was treated with hydrochloric acid (HCl) to remove byproducts. As prepared, Si was characterized using various techniques, including XRD, XRF, FT-IR, XPS, SEM, and BET, which confirmed the successful production, chemical purity, and structural retention of Si. Furthermore, the coin cell was fabricated using Si as an anode, and the electrochemical performance was analyzed. The charge/discharge cycling tests at 1 C and 0.02~2 V (vs. the Li condition) revealed the effects of silicon content, wettability, and interfacial compatibility on electrode performance. Conversely, for better understanding, a long-term cycling test was conducted at 1 C rate, 0–1.5 V (vs. Li) to evaluate capacity retention. Our findings highlight the potential application of silicon (Si) aerogels produced from silica (SiO₂) aerogels by magnesiothermic reduction to improve lithium-ion battery performance. Full article

Exploring novel two-dimensional layered transitional metal dichalcogenides and elucidating their reaction mechanism are critical to designing promising anode materials for lithium-ion batteries (LIBs). Herein, a novel layered TaS₂ nanosheet was obtained via a typical solid-phase reaction method followed by a simple ball-milling treatment, and first explored experimentally as an anode for LIBs. The TaS₂ nanosheet anode delivered an excellent cycling stability, with 234.6 mAh g⁻¹ after 500 cycles at 1 A g⁻¹. The optimized performance could be attributed to the large interlayer spacing, high conductivity, and reduced size of the TaS₂ nanosheet, which effectively alleviated the volume change during the reaction process and accelerated the Li⁺ or e⁻ transport. Especially, the TaS₂ nanosheet anode presented an unusual intercalation reaction mechanism, accompanied with a reversible phase transition from the 2H to the 1T phase during the first de-lithiation process, which is evidenced by the multiple ex situ characterizations, further revealing the enhanced electrochemical performance results from the 1T phase with the larger interlayer spacing and higher electrical conductivity. This work provides a novel insight into the intercalation reaction mechanism of TaS₂, which shows potential in high-performance LIBs. Full article

In recent years, transition metal oxides (TMOs) have emerged as promising candidates for anode materials in lithium-ion batteries (LIBs) owing to their high theoretical capacities. Regrettably, most TMOs exhibit poor electronic/ionic conductivity and undergo substantial volume expansion during the lithiation/delithiation processes. In this study, an electrostatic spinning method using polyacrylonitrile, graphene, and iron(III) acetylacetonate as precursors was employed to synthesize the Fe₃O₄@G/C composite through carbon coating and graphene doping. The composition, phase structure, and morphology of the Fe₃O₄@G/C composite were thoroughly investigated. The electrochemical performance of the Fe₃O₄@G/C composite as a lithium-ion battery anode was evaluated through a continuous charge–discharge cycling test. After 100 cycles at a current density of 0.1 A/g, the specific capacity of the Fe₃O₄@G/C material remained at 595.8 mAh/g. Additionally, the incorporation of graphene leads to a reduction in the electron orbital energy of Fe, which was verified by comparing the density of states (DOS) before and after the doping. Simultaneously, the electrochemical performance of CoO@G/C and NiO@G/C composites further demonstrates that doping transition metal oxides with graphene can enhance their performance as anodes for lithium-ion batteries. We anticipate that this design concept will open new avenues for the development of transition metal oxides (TMOs) and propel their adoption in practical applications. Full article

Silicon-based anode materials are used to improve the performance of next-generation high-energy-density lithium-ion batteries (LIBs). However, the inherent limitations and cost of these materials are hindering their mass production. Commercial graphite can overcome the shortcomings of silicon-based materials and partially reduce their cost. In this study, a high-performance, low-cost, and environmentally friendly composite electrode material suitable for mass production was developed through optimizing the silicon content of commercial silicon–graphite composites and introducing a small amount of graphene and carbon nanofibers. This partially overcomes the inherent limitations of silicon, enhances the interface stability of silicon-based materials and the cycle stability of batteries, and reduces the irreversible capacity loss of the initial cycle. At a silicon content of 15 wt%, the initial Coulombic efficiency (ICE) of the battery was 65%. Reducing the silicon content in the composite electrode from 15% to 10% increased the ICE to 70% and improved the first lithiation and delithiation capacities. The battery exhibited excellent cycle stability at a current density of 0.1 A g⁻¹, retaining approximately 65% of its capacity after 100 cycles, good performance at various current densities (0.1–1 A g⁻¹), and an excellent reversible performance. Full article

Despite their high specific capacity, magnetron-sputtered Si/Al thin films face rapid capacity decay due to stress-induced cracking, delamination, and detrimental electrolyte reactions. This study introduces a carbon-coated composite anode that overcomes these limitations, delivering superior reversible capacity, exceptional rate capability, and stable cycling performance. An electrochemical evaluation reveals that the CF-Si/Al@C-500-1h composite exhibits marked enhancements in capacity retention (43.5% after 100 cycles at 0.6 A·g⁻¹) and rate capability, maintaining 579.1 mAh·g⁻¹ at 3 A·g⁻¹ (1 C). The carbon layer enhances electrical conductivity, buffers volume expansion during lithiation/delithiation, and suppresses silicon aggregation and electrolyte side reactions. Coupled with an aluminum framework, this architecture ensures robust structural integrity and efficient lithium-ion transport. These advancements position CF-Si/Al@C-500-1h as a promising anode material for next-generation lithium-ion batteries, while insights into scalable fabrication and carbon integration strategies pave the way for practical applications. Full article

This study explores the electrochemical properties of additive-free NiCo₂O₄ derived from NiCo–metal–organic frameworks (MOFs) as a high-performance anode material for lithium-ion batteries (LIBs), excluding the effect of additives. NiCo-MOF was synthesized via an ultrasonic-assisted method and deposited on stainless steel foils using alternating current electrophoretic deposition (AC-EPD). The resulting thin films exhibited outstanding cycling stability and rate performance, maintaining a specific capacity of ~1200 mAh/g over 250 cycles at a high current density of 2.35 A/g, with nearly 100% Coulombic efficiency. Differential capacity analysis revealed enhanced redox activity at 0.8 V and 1.7 V during lithiation and delithiation, attributed to the decomposition of NiCo₂O₄ into metallic Ni and Co, followed by their oxidation to Ni²⁺ and Co³⁺, respectively. The gradual activation of electroactive sites, coupled with improved electrode kinetics and structural adjustments, contributed to the observed capacity increase over cycles. These findings underscore the potential of NiCo₂O₄ as a robust and efficient anode material for next-generation LIBs. Full article

The innovative design of the microstructure of silicon-based composite anodes in Li-ion batteries holds great potential for overcoming inherent limitations, such as the significant volume change experienced by silicon particles. In this study, TiFeSi₂/C composites prepared using micro, nano, and porous silicon showed reversible capacities of 990.45 mAh.g⁻¹, 1137.69 mAh.g⁻¹, and 1045.43 mAh.g⁻¹ at C/10. The results obtained from the electrochemical characterization show that the porous structure of the composite anode material created via acid etching reduced silicon expansion during the lithiation/delithiation processes. The void spaces formed in the inner structure of the porous silicon and the presence of carbon increased the electronic conductivity between the silicon particles and, on the other hand, lowered the overall diffusion distance of Li⁺. This study confirms that TiFeSi₂/C prepared with porous silicon dispersed in a transition metal matrix delivers better electrochemical performance compared to micro and nano silicon with a retention of 80.16%. Full article

Flexible electrodes are highly desirable for next-generation wearable lithium-ion batteries. To achieve high-capacity flexible electrode materials, SnO₂ with high theoretical capacity has been introduced into electrodes and shows promising capacity. However, the electrodes are still confronted with major challenges in terms of inferior rate capability and cycling stability, which are caused by large volume changes of SnO₂ during the lithiation/delithiation process. Here, we adopt an adsorption assembly strategy to fabricate a flexible carbon fiber/SnO₂@rGO electrode that effectively stabilizes the volume changes of SnO₂ and enhances the charge transport kinetics in electrodes. The sandwich-like structure endows the electrode’s high flexibility and succeeds in improving both rate capability and cycling stability. The flexible carbon fiber/SnO₂@rGO electrode delivers a high capacity of 453 mAh g⁻¹ at 50 mA g⁻¹ and outstanding capacity retention of 88% after 1000 cycles at 2 A g⁻¹. Full article

Cobalt (II, III) oxide (Co₃O₄) has recently gained attention as an alternative anode material to commercial graphite in lithium-ion batteries (LIBs) due to its superior safety and large theoretical capacity of about 890 mAh g⁻¹. However, its practical application is limited by poor electrical conductivity and rapid capacity degradation because of significant volume increases and structural strain during repeated lithiation/delithiation cycles. To address these issues, this work presents a novel approach to synthesizing carbon-composited Co₃O₄ microspheres (Co₃O₄@C), using abietic acid (AA) as a carbon source to increase conductivity and structural stability. The resulting Co₃O₄@C anodes show an impressive discharge capacity of 1557.4 mAh g⁻¹ after 200 cycling processes at a current density of 0.1 C, representing a significant improvement over bare Co₃O₄. This study demonstrates the potential of carbon-compositing as a strategy to mitigate the limitations of Co₃O₄ and extend its cyclability, making it a viable candidate for next-generation LIB anodes. Full article

Silicon anodes present a high theoretical capacity of 4200 mAh/g, positioning them as strong contenders for improving the performance of lithium-ion batteries. Despite their potential, the practical application of Si anodes is constrained by their significant volumetric expansion (up to 400%) during lithiation/delithiation, which leads to mechanical degradation and loss of electrical contact. This issue contributes to poor cycling stability and hinders their commercial viability, and various silicon–carbon composite fabrication methods have been explored to mitigate these challenges. This review covers key techniques, including ball milling, spray drying, pyrolysis, chemical vapor deposition (CVD), and mechanofusion. Each method has unique benefits; ball milling and spray drying are effective for creating homogeneous composites, whereas pyrolysis and CVD offer high-quality coatings that enhance the mechanical stability of silicon anodes. Mechanofusion has been highlighted for its ability to integrate silicon with carbon materials, showing the potential for further optimization. In light of these advancements, future research should focus on refining these techniques to enhance the stability and performance of Si-based anodes. The optimization of the compounding process has the potential to enhance the performance of silicon anodes by addressing the significant volume change and low conductivity, while simultaneously addressing cost-related concerns. Full article

Silicon (Si) has attracted worldwide attention for its ultrahigh theoretical storage capacity (4200 mA h g⁻¹), low mass density (2.33 g cm⁻³), low operating potential (0.4 V vs. Li/Li⁺), abundant reserves, environmentally benign nature, and low cost. It is a promising high-energy-density anode material for next-generation lithium-ion batteries (LIBs), offering a replacement for graphite anodes owing to the escalating energy demands in booming automobile and energy storage applications. Unfortunately, the commercialization of silicon anodes is stringently hindered by large volume expansion during lithiation–delithiation, the unstable and detrimental growth of electrode/electrolyte interface layers, sluggish Li-ion diffusion, poor rate performance, and inherently low ion/electron conductivity. These present major safety challenges lead to quick capacity degradation in LIBs. Herein, we present the synergistic effects of nanostructured silicon and SrTiO₃ (STO) for use as anodes in Li-ion batteries. Si and STO nanoparticles were incorporated into a multiwalled carbon nanotube (CNT) matrix using a planetary ball-milling process. The mechanical stress resulting from the expansion of Si was transferred via the CNT matrix to the STO. We discovered that the introduction of STO can improve the electrochemical performance of Si/CNT nanocomposite anodes. Experimental measurements and electrochemical impedance spectroscopy provide evidence for the enhanced mobility of Li-ions facilitated by STO. Hence, incorporating STO into the Si@CNT anode yields promising results, exhibiting a high initial Coulombic efficiency of approximately 85%, a reversible specific capacity of ~800 mA h g⁻¹ after 100 cycles at 100 mA g⁻¹, and a high-rate capability of 1400 mA g⁻¹ with a capacity of 800 mA h g⁻¹. Interestingly, it exhibits a capacity of 350 mAh g⁻¹ after 1000 lithiation and delithiation cycles at a high rate of 600 mA hg⁻¹. This result unveils and sheds light on the design of a scalable method for manufacturing Si anodes for next-generation LIBs. Full article

Silicon (Si) is recognized as a promising candidate for next-generation lithium-ion batteries (LIBs) owing to its high theoretical specific capacity (~4200 mAh g⁻¹), low working potential (<0.4 V vs. Li/Li⁺), and abundant reserves. However, several challenges, such as severe volumetric changes (>300%) during lithiation/delithiation, unstable solid–electrolyte interphase (SEI) formation, and inherently low electrical and ionic conductivity, impede its practical application. To mitigate these challenges, direct contact between the surface of the Si particle and the electrolyte must be prevented. In this review, we elucidated the surface coating strategies to enhance the electro–chemical performance of Si-based materials. We identified the impact of various coating methods and materials on the performance of Si electrodes. Furthermore, the integration of coating strategies with nanostructure design can effectively buffer Si electrode volume expansion and prevent direct contact with the electrolyte, thereby synergistically enhancing electrochemical performance. We highlight opportunities and perspectives for future research on Si-negative electrodes in LIBs, drawing on insights from previous studies. Full article