Anode For Li-ion Batteries Research Articles

Nanocarbon Florets with Synthetically Tunable Porosity as High-Rate Anodes for Li-ion Batteries

Nanocarbon Florets with Synthetically Tunable Porosity as High-Rate Anodes for Li-ion Batteries

Waxberry-like TiO2 with Synergistic Surface Modification of Pyrolytic Carbon Coating and Carbon Nanotubes as an Anode for Li-Ion Battery.

Titanium dioxide (TiO2) as an anode material for lithium-ion batteries (LIBs) has the advantages of tiny volume expansion, high operating voltage, and outstanding safety performance. However, due to the low conductivity of TiO2 and the slow diffusion rate of lithium ions (Li+), it is limited in the application of LIBs. Therefore, waxberry-like TiO2 comodified by pyrolytic carbon coating and carbon nanotubes was prepared in this work. The waxberry-like TiO2 with nanorods on its surface shortens the diffusion distance of Li+. Carbon nanotubes and waxberry-like TiO2 are tightly combined through electrostatic assembly and form a cross-linked conductive network to provide more electron transmission paths. A thin layer of pyrolytic carbon wraps carbon nanotubes and waxberry-like TiO2, which enhance the conductivity of the composites and ensure the structural integrity of the materials throughout the cycling process. The experimental data revealed that the discharge-specific capacity of TiO2@CNT@C is 170.5 mAh g-1 after 3000 cycles at a large current density of 5 A g-1, and the discharge-specific capacity is still 143 mAh g-1 at the superhigh rate of 10 A g-1, which provides excellent rate performance and cyclic stability. The efficient dual-carbon modification strategy could potentially be extended to other materials.

G-C3N4 integrated silicon nanoparticle composite for high-performance Li-ion battery anodes

g-C3N4 integrated silicon nanoparticle composite for high-performance Li-ion battery anodes

Rational design of alginate-derived network binder for high-performance silicon-based anodes in Li-ion batteries

This study developed a novel alginate-derived network binder, SAH, to enhance the performance and stability of silicon-based anodes in lithium-ion batteries. Integrating acrylic acid and 2-hydroxyethyl acrylate with sodium alginate through a one-pot polymerization and in-situ cross-linking method, SAH effectively addresses the volumetric expansion challenges associated with silicon anodes. This innovative binder maintains the structural integrity of the silicon anode through its rigid acrylic acid component, while the flexible acrylic-2-hydroxyethyl ester serves as a dynamic buffer to enhance flexibility. Sodium alginate contributes its intrinsic beneficial properties and imparts a robust three-dimensional network structure through effective coupling, allowing the binder to accommodate silicon volume changes during battery operation. Consequently, lithium-ion batteries incorporating this binder exhibited improved stability and extended cycle life, achieving an impressive capacity retention rate of 87.3 % after 100 cycles at 0.5C. This study highlights the potential of biopolymeric materials in enhancing the functionality of silicon-based anodes, contributing to the ongoing development of high-performance energy storage technologies.

Self-supporting Mg-Sn alloy anode for high-energy Li-ion batteries

Due to advantages such as low reaction potential, high gravimetric and volumetric capacity, and minimal structural changes during interaction with lithium, the research on Mg anodes in Li-ion batteries has garnered significant attention. However, the slow diffusion kinetics of Li in Mg limits its further advancement. In this study, we designed an ultrathin, flexible, and self-supporting Mg–Sn alloy anode featuring an interleaved two-phase distribution. The electrode was fabricated through a simple one-step magnetron sputtering method, which circumvents the need for complex procedures like slurry preparation and coating. Both theoretical calculations and experimental results indicate that the introduction of a second phase(Mg2Sn phase) significantly enhances the interaction between Mg and Li, thereby unlocking the lithium storage capabilities of Mg. The developed Mg–Sn alloy electrode demonstrates a charge specific capacity of 1,618 mAh g−1 at 50 mA g−2 and maintains a capacity of 421 mAh g−1 after 50 cycles.

Evaluating the efficacy of strategies for silicon/graphite anodes in Li-ion batteries

Recent research has been focused on the utilization of silicon (Si) based anode for high-energy–density lithium-ion batteries (LIBs) owing to the high theoretical capacity of Si (∼ 3578 mAh g−1). To mitigate the intrinsic volume change of Si (∼ 300 %) upon cycling, research focused on the co-utilization strategy of Si with graphite anode (SiG) in the form of the blending (physical mixture of Si and graphite) and composite (building up material containing Si and graphite). However, the underlying mechanisms of the two strategies that cause different electrochemical results have not been thoroughly explored. In this study, we aimed to investigate the composite anode (C-SiG-650) and blending anode (B-SiG-650) with a specific capacity of ∼ 650 mAh g−1 in terms of electrochemical performance. The composite electrode exhibited a uniform distribution of SiG particles, which helps for faster Li+ ion transport into bulk, whereas the blending electrode exhibited aggregation of SiG particles, which impedes the Li+ ion transport into the bulk. As a result, the composite anode exhibited superior capacity retention and rate performance compared to the blending electrode. Moreover, the composite anode containing full-cell delivered a higher specific capacity of 162 mAh g−1 and capacity retention of 73.58 % after 100 cycles. This implies that directly utilizing composite anode with a low-capacity SiG particle is a promising way to achieve high volumetric energy density for commercial device applications.

DFT and AIMD studies of SnFe2O4 as a promising anode for Li-ion batteries

Tin ferrite (SnFe2O4) is considered as a perspective lithium ion battery anode, owing to its low cost, large theoretical capacity, low toxicity, structural stability, and easy synthesis method. Prior research has been done on the performance of lithium storage in SnFe2O4. However, the electrochemical processes that take place during the lithiation-delithiation cycle of LIBs have not been explained in depth yet. In order to understand the discharge mechanism in the LixSnFe2O4 anode (x = 0 to 2), we systematically investigated its electrochemical characteristics, structural and electronic properties, average formation energies, open-circuit voltages, diffusion coefficient, and volume expansion using density functional theory. According to our calculations, an increase in Li concentration x up to 1.125 leads to enhanced stability of the LixSnFe2O4 systems. During this process, Li+ ions prefer to be intercalated at the octahedral 16c sites, inducing the displacement of Sn2+ ions from tetrahedral sites 8a to 16c and 48f sites. However, for 1.125 < x < 2, lithium ions tend to occupy the less stable sites 48f , which reduces the stability of LixSnFe2O4 systems.Additionally, the calculated lithium intercalation voltage for full lithiation Li1.125SnFe2O4 is equal to 1.5 V, and the distortion of the LixSnFe2O4 system occurs at a voltage of 0.75 V, which is in well agreement with experimental results. The Li-coefficient diffusion on SnFe2O4 at 300 K is calculated by ab initio molecular dynamic simulation and equal to 8.22 × 10−8 cm2/s, which indicates the excellent mobility of Li ions in SnFe2O4. Considering all these results, we can suggest SnFe2O4 as a promising negative electrode material for lithium-ion batteries.

Facile Preparation of Co3O4/Super P/Multi-Walled Carbon Nanotube Films for High-Performance Li-Ion Battery Anodes

Facile Preparation of Co3O4/Super P/Multi-Walled Carbon Nanotube Films for High-Performance Li-Ion Battery Anodes

First-principles study on the lithiation process of amorphous SiO anode for Li-ion batteries with Bayesian optimization.

Amorphous silicon monoxide (a-SiO), which contains Si atoms with various valence states, has attracted much attention as a high-performance anode material for lithium (Li) ion batteries (LIBs). Although current experiments have provided some information during charge/discharge cycles, further investigation of structural changes at the atomic scale is needed. To investigate the lithiation process of a-SiO using first-principles simulations and machine learning techniques, we developed a computational code employing Bayesian optimization to efficiently identify stable sites for Li insertion in the large search-space of amorphous models to reproduce the actual lithiation process and compared this approach to the conventional random scheme by applying it to an a-SiO model previously generated with neural network potentials. The lithiation process based on Bayesian optimization resulted in lower formation energies compared to the conventional random scheme, indicating a more stable structure. During lithiation, Li atoms tended to enter the silicon (Si) phase after the SiO2 phase, in agreement with experimental results. We analyzed the structural changes and observed significant differences in the structural evolution between the conventional and new schemes. Our study highlights the significant influence of the lithiation process on the structural transformation of a-SiO materials, which in turn affects the reversible capacity of the material. These findings will provide a framework for improving the performance and lifetime of a-SiO materials.

Covalent Carbide Interconnects Enable Robust Interfaces and Thin SEI for Graphite Anode Stability under Extreme Fast Charging.

Carbonaceous and carbon-coated electrodes are ubiquitous in electrochemical energy storage and conversion technologies due to their electrochemical stability, lightweight nature, and relatively low cost. However, traditional reliance on conductive additives and binders leads to impermanent electrical pathways. Here, a general approach is presented to fabricate robust electrodes with a progressive failure mechanism by introducing carbide-based interconnects grown via carbothermal conversion of (5 wt%) titanium hydride nanoparticles. This method concurrently enhances both electrical and mechanical properties within the electrode architecture. The resulting chemical bonding between active materials establishes a novel mechanism to maintain stable electrical pathways during cycling. Employed as Li-ion battery anodes, these electrodes exhibit improved cyclability, achieving 80% capacity retention after 800 fast-charge cycles at moderate loading (1 mAh cm- 2). High loading cells with areal capacity of 3 mAh cm-2 show significantly improved cycle lifeover the same number of cycles. This performance improvement is attributed to the absence of significant impedance growth and a thinner solid electrolyte interphase (SEI) layer formed at high current densities (4C) as demonstrated by X-ray photoelectron spectroscopy and transmission electron microscopy studies. The enhanced conductivity facilitates SEI formation, lowering ionic impedance and mitigating lithium plating, ultimately leading to the reported extended cycle life.

Self-Driven SiO2/C Nanocomposites from Cultured Diatom Microalgae for Sustainable Li-Ion Battery Anodes: The Role of Impurities

Self-Driven SiO₂/C Nanocomposites from Cultured Diatom Microalgae for Sustainable Li-Ion Battery Anodes: The Role of Impurities

Regeneration of spent graphite via graphite-like turbostratic carbon coating for advanced Li ion battery anode

Recycling spent graphite (SG) from lithium-ion batteries is an effective approach to reduce resource waste and address environmental issues. The main reasons for the capacity degradation of graphite anode are the structural destruction and changes in surface composition during the cycling process. However, repairing the graphite with satisfactory electrochemical properties remains a significant challenge due to the lack of efficient recycling methods. Herein, a low-temperature magnesium catalytic method is developed to reconstruct turbostratic carbon coating and repair defects in SG at 900 °C. The dense turbostratic carbon not only effectively repairs the surface damage of the SG and mitigates the occurrence of side reactions but also improves the Li+ and electron transfer kinetics of SG. The regenerated graphite anode exhibits high initial Coulombic efficiency (ICE) of 86.2 %, a high capacity of 350 mAh g−1 after 500 cycles at 0.5 C with a capacity retention of 96.5 %, which reaches the requirements of commercial applications. Furthermore, a techno-economic analysis shows that this strategy has higher environmental and economic benefits compared to conventional recycling methods.

Ti3C2Tx MXene coated 3D ordered macroporous germanium anodes for Li-ion batteries with enhanced cycling stability and fast Li-ion mobility

The current trend in electronic device development and electric vehicle technology has resulted in A growing need for negative electrode materials that possess high capacity and quick Li-ion transport properties. Ge-based materials are considered the very promising candidates owing to their high theoretical capacity and facile alloying reaction with Li. In order to enhance the rate of Li-ion diffusion and account for the volume change of over 300 %, a Ti3C2Tx MXene coated 3D ordered macroporous germanium (3DOM Ge@MXene) structure was successfully developed. The 3DOM Ge@MXene provides a 1490 mAh g−1 initial reversible capacity at 0.32 A g−1. Additionally, after 100 cycles, it displays a consistent cycling ability of 1034 mAh g−1. The MXene coating also improves the material's Li-ion rapid transfer performance, with Li-ion diffusion coefficient of 1.35 × 10−10 cm2s−1 for anodic and 2.2 × 10−10 cm2s−1 for cathodic.

Enhancing Electrochemical Performance of Si@CNT Anode by Integrating SrTiO3 Material for High-Capacity Lithium-Ion Batteries

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.

Element Screening Engineering for High-Entropy Alloy Anodes: Achieving Fast and Robust Li-Storage With Optimal Working Potential.

While the high-entropy strategy is highly effective in enhancing the performance of materials across various fields, an optimal methodology for selecting component elements for performance optimization is still lacking. Here the findings on uncovering the element selection rules for rational design of high-entropy alloy anodes with exceptional lithium storage performance are reported. It is investigated high-entropy element screening rules by modifying stable diamond-structured Ge with P to induce a tetrahedrally coordinated sphalerite structure for enhanced metallic conductivity, further stabilized by incorporating Zn and other elements. Moreover, both theoretical and experimental results confirm that Li-storage performance improves with increasing atomic number: BZnGeP3 < AlZnGeP3 < GaZnGeP3 < InZnGeP3. InZnGeP3-based electrodes demonstrate the highest Li-ion affinity, fastest electronic and Li-ion transport, largest Li-storage capacity and reversibility, and best mechanical integrity. Further element screening based on the above criteria leads to high entropy alloy anodes with metallic conductivity like GaCuSnInZnGeP6, GaCu(or Sn)InZnGeP5, CuSnInZnGeP5, InZnGePSeS(or Te), InZnGeP2S(or Se) which show superior Li-storage performances. The excellent phase stability is attributed to their high configurational entropy. This study offers profound insights into element screening for high-entropy alloy-based anodes in Li-ion batteries, providing guidance and reference for the element combination and screening of other high-entropy functional materials.

Robust self-healing ion-conductive interlocking dual-network binder based on gradient dynamic bonding for advanced SiO anodes in Li-Ion batteries

Silicon-based (e.g., SiO) anodes have attracted much attention for their high specific capacity; however, poor conductivity and dramatic volume change during the charge/discharge cycling hinder their commercial application in high energy density lithium-ion batteries (LIBs). Ideal binders hold a decisive effect on inhibiting the volume effect of the silicon-based anode. Herein, inspired by the hierarchical structure of living organisms, we design a multifunctional self-healing interlocking dual-network binder based on gradient dynamic bonding and apply the binder to SiO anode toward high specific capacity and long-term cycle performance. Specifically, rigid polyacrylic acid (PAA) and flexible polylipoic acid (PTA) are interlocked by gradient dynamic bonding containing of disulfide linkage, metalcoordination and hydrogen bonding. The obtained binder has strong adhesion, high mechanical toughness, fast self-healing performance and high ionic conductivity, which enable the SiO anode effectively buffering the volume expansion and exhibiting excellent cycling stability. The SiO electrode with the new binder delivers a high capacity of 884.8 mAh/g at a current density of 0.5 A/g after 500 cycles and a high capacity of 765.2 mAh/g at a high mass loading of 3.0 mg cm−2 after 100 cycles. Moreover, the assembled SiO||NCM811 full cell achieves a reversible capacity of 169.75 mAh/g with capacity retention of 77.5 % after 100 cycles. This work offers a new method for the design of versatile self-healing binder adaptive to electrode volume change, so as to accelerate the application of the silicon-based anode.

Fly-ash derived crystalline Si (cSi) Improves the capacity and energy density of LiNi0.8Co0.1Mn0.1O2 battery: Synthesis and performance

For decades, graphite has been the key ingredient in the anode of Li-ion batteries (LIBs). The search for high-capacity anode materials for Li-ion batteries (LIBs) has led to increasing interest in silicon (Si) as a potential replacement for graphite. This study presents an innovative approach to synthesizing crystalline Si (cSi) from type C fly ash, addressing both the need for improved LIB anodes and the challenge of industrial waste management. Our novel process involves a stepwise method of extraction, gelation using various mineral acids (HCl, H2SO4, and HNO3), magnesiothermic reduction, and purification. X-ray diffraction and energy-dispersive X-ray spectroscopy confirmed the production of high-purity SiO2 and cSi. Notably, a cSi-doped graphite anode (5 % Si) paired with LiNi0.8Mn0.1Co0.1O2 (NMC811) in a cylindrical cell achieved a minimum specific discharge capacity of 388 mAh/ganode after formation, surpassing the theoretical capacity of graphite (372 mAh/g). This demonstrates that even a small amount of cSi can significantly enhance anode performance. Our scalable, simple, and economical process offers a dual benefit: improving battery characteristics while providing an efficient method for fly ash waste utilization. This approach paves the way for sustainable production of high-performance LIB anodes while addressing critical waste management challenges.

Manufacturing lithium-ion anodes from silicon recovered from end-of-life solar panels

With the rapid growth of solar energy, the recycling or re-use of used solar panels has become a key issue. Recycling high-value photovoltaic silicon from solar cells is an important step towards achieving “carbon neutrality.” In this paper, an efficient and high-value recycling strategy is employed to convert recycled silicon from discarded solar cells into lithium-ion anode materials. In this case, the recycled PV silicon is etched with hydrofluoric acid (HF) to create a porous silicon structure. This structure is designed to withstand the expansion stress of the electrodes. After surface modification with citric acid and carbon nanotubes to enhance the electrical conductivity of the recycled silicon and buffer the electrode from stress expansion during lithium storage and release, lithium difluorooxalate borate was added to pre-treat the surface of the recycled photovoltaic silicon through heat treatment. This process creates a robust and fast lithium-ion conductive interface enriched with LiF, Li2C2O4, LiBO2, and Li2B4O7. Density Functional Theory (DFT) calculations were performed to investigate the electronic structure of the synthesized materials, revealing their remarkable electronic conductivity and atomic bonding characteristics. When used as an anode for Li-ion batteries, W-pSi@C/CNTs exhibited high initial coulombic efficiency with stable cycling, demonstrating a capacity of 2040 mAh/g at 0.2 A/g for 200 cycles. In addition, this high-value recycling will help promote the development of renewable energy in an economically and environmentally sustainable manner.

Artificial Electron Channels Enable Contact Prelithiation of Li-Ion Battery Anodes with Ultrahigh Li-Source Utilization.

Contact prelithiation is widely used for compensating the initial capacity loss of lithium-ion batteries (LIBs). However, the low Li-source utilization suffering from the deteriorated contact interfaces results in cycling degeneration. Herein, Li-Ag alloy-based artificial electron channels (AECs) are established in Li source/graphite anode contact interfaces to promote Li-source conversion. Due to the shielding effect of the Li-Ag alloy (50 at. % Li) on Li-ion diffusion, the dry-state corrosion of contact interfaces is restricted. The unblocked electronic conduction across the AEC-involved interface not only facilitates the Li source conversion but also accelerates the prelithiation kinetics during the wet-state process, resulting in an ultrahigh Li-source utilization (90.7%). Thereby, implementing AEC-assisted prelithiation in a LiNi0.5Co0.2Mn0.3O2 pouch cell yields a 35.8% increase in energy density and stable cycling over 600 cycles. This finding affords significant insights into the construction of an efficient prelithiation technology toward the development of high-energy LIBs.

Supramolecular-driven construction of multilayered structure by modified hummers method for robust silicon anode

Rational design of nano-structured silicon (Si)-based composites to enhance the structural stability and electrical conductivity is key to developing high-performance lithium-ion batteries. Here, a supramolecular self-assembly strategy is first adopted to prepare Si@rGO composites with multilayered structure through the modified Hummers method. Experimental results demonstrate that Si@SiOx NPs are uniformly distributed in rGO interlayers by supramolecular interaction. In situ Raman results suggest that the multilayer embedded structure can effectively confine the Si NPs and preserve the integrity of the electrode. Theoretical calculations indicate that the imbalanced charge distribution in inner interface shows enhanced dual-interfacial bonding and charge interactions in the Si@SiOx⊂rGO composite, resulting in an interfacial electric-field between Si NPs and rGO for fast ionic and charge migration. The fabricated MSi@SiOx⊂rGO anode with high Si contents (> 60 wt.% Si) exhibits superior Li-ion reaction kinetics (882.4 mAh g−1 at 8 A g−1), durable structural stability (0.031% per cycle capacity attenuation with an average Coulombic efficiency > 99.7%), and low expansion rate. High-mass-loading electrodes show great potential for commercial applications. Full cells assembled with LiCoO2 cathodes also demonstrate outstanding Li-ion storage properties. This work provides insights into the interfacial design of Si@C anodes for advanced Li-ion battery.