Anode Material Research Articles

Porous hexagonal Mn 5O 8 nanosheets as fast-charging anode materials for lithium-ion batteries

Porous hexagonal Mn ₅O ₈ nanosheets as fast-charging anode materials for lithium-ion batteries

Facile fabrication of Fe3O4@C composites from cellulose of Nypa fruticants shell toward advanced anode materials in Li-ion batteries

Facile fabrication of Fe3O4@C composites from cellulose of Nypa fruticants shell toward advanced anode materials in Li-ion batteries

Multi-dimensional carbon modification strategy for lithium-ion battery anodes: Carbon-covered TiP2O7 supported by 3D carbon skeleton

Carbon coating is a beneficial method for improving surface capacitive behavior, electron transfer kinetics and cyclic stability of three-dimensional lattice lithium-embedded anode materials. Herein, we adopt one-step pyrolysis to achieve carbon-covered TiP2O7 supported by a three-dimensional carbon skeleton utilizing phytic acid and glucose as carbon sources. The two-dimensional amorphous carbon layer on TiP2O7 surface improves the initial Coulombic efficiency and rate capacity by inhibiting the irreversible embedding of lithium ions and reducing the interfacial charge transfer impedance. The three-dimensional carbon skeleton not only forms a conductive pathway between the carbon-covered TiP2O7, but also its large specific surface area, randomly oriented and defective carbon layer provide extra lithium storage sites and capacitive contribution. In addition, the specific capacity of the TiP2O7/C composite is still as high as 314.5 mA h g−1 after 1000 cycles at 1 A g−1. A TiP2O7/C//LiFePO4 full cell delivers a high energy density of 273.96 Wh kg−1 at 0.153 kW kg−1, and retains 114.43 Wh kg−1 even at the power density of 4.086 kW kg−1. The multi-dimensional carbon modification strategy has improved the electrochemical performance of TiP2O7-based anode materials, providing a model for synthesizing other high-performance anode materials.

Synthesis and Characterization of Silicon Nanoparticles from Coal Fly Ash Using Ultrasonication as a Battery Anode

Fly ash, a byproduct of coal combustion, is rich in silica, alumina, and other minerals, making it a valuable resource for extracting high-purity silicon. The synthesis of silicon nanoparticles from coal fly ash involves several critical steps, including the extraction of silica (SiO2) via the sol-gel method, reduction of silica to silicon using the metallothermic method, and subsequent ultrasonication to achieve nanoscale particles. Studies have shown that fly ash can contain up to 49.21% silica, which can be further purified to 93.52% via chemical extraction methods such as acid leaching and alkali dissolution. The reduction of silica to silicon is carried out using the metallothermic method, which involves the use of magnesium-reducing agents to convert SiO2 to elemental silicon. This process produces silicon with a purity of about 61.3%, which can be further increased through ultrasonication. Ultrasonication is a technique that uses high-frequency sound waves to break particles into smaller sizes, resulting in more uniform and homogeneous nanoparticles. In this study, ultrasonication for 60 and 120 min reduced the average particle size of silicon from 208.94 nm to 58.87 nm and 20.13 nm, respectively, and increased the silicon content to 74.6% and 72.7%. X-ray diffraction (XRD) and distribution particle analyses confirmed the particle size reduction and homogeneity of silicon nanoparticles, indicating the effectiveness of ultrasonication in producing high-quality silicon nanoparticles. The synthesized silicon nanoparticles have significant potential applications, particularly as anode materials in lithium-ion batteries, due to their increased surface area and improved electrochemical properties. Furthermore, the use of fly ash as a raw material for the synthesis of silicon nanoparticles not only provides a cost-effective and environmentally friendly alternative to traditional silica sources but also helps in reducing the environmental impact of fly ash disposal. The integration of the methods and findings of this study underscores the feasibility and benefits of using coal fly ash for the sustainable production of silicon nanoparticles, which can be utilized in energy storage as anode materials in lithium-ion batteries.

Theoretical design of graphene/tungsten dichalcogenide (Gr/WX2, X=S, Se) heterostructures used for anode materials of LIBs from DFT calculations

2D van der Waals heterostructures are highly promising for Lithium-ion batteries (LIBs), offering excellent energy capacity and extended lifespan when used as anodes. In this study, we systematically investigate the geometrical structures and electronic properties of graphene/tungsten dichalcogenide (Gr/WX2, X=S, Se) heterostructures, focusing on lithium (Li) atom adsorption and movement in these materials using first-principles calculations through density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations. Our results reveal that the Gr/WX2 heterostructures possess excellent structural stability, with mechanical strength validated by their elastic constants. The diffusion barriers of Li atoms in Gr/WS2 and Gr/WSe2 heterostructures are competitive compared with other anode materials. Additionally, the Li diffusion coefficients at 300 K for Gr/WS2 and Gr/WSe2 are also surpassing those observed in pristine Gr. Furthermore, Gr effectively lowers the average open-circuit voltage (OCV) of Gr/WX2 heterostructures to optimal levels, with Gr/WS2 at 0.29V and Gr/WSe2 at 0.25V. The Gr/WS2 and Gr/WSe2 heterostructures after adsorption of Li exhibit remarkable thermal stability at 300K, maintaining their structural integrity throughout the simulation period. Our research provides comprehensive theoretical guidance for the practical development and application of Gr/WX2 heterostructures as anode materials in LIBs.

Unlocking the potential of Mg-ion batteries: Cu2C MXene anode with ultrahigh storage and energy density with rapid Mg diffusion

Magnesium-ion batteries hold immense promise for the future of electrical energy storage due to the abundant availability of magnesium metal and the efficient energy storage capacity of divalent magnesium ions which has the potential to revolutionize both large-scale stationary applications and portable devices. MXenes, encompassing transition metal carbides/nitrides/carbonitrides, are still considered newcomers in the domain of 2D nanomaterials, especially regarding their utilization in energy storage applications. In this work, we employed first principles based DFT calculations to comprehensively evaluate the electrochemical behavior of 2H phase Cu-based MXene (Cu2C) monolayer as promising anode material for Mg-ion batteries. The stability of the Cu2C monolayer was assessed through calculations of negative cohesive energy, positive phonon frequencies, and AIMD simulations to confirm stability at room temperature along with superior mechanical strength. The simulation outcomes show that strong affinity for Mg ions to the Cu2C monolayer, which is attributed to metallic character, suggesting good electronic conductivity and aslo, the calculated negative adsorption energy of −1.25 eV, indicating a favorable interaction for potential battery applications. The Cu2C monolayer emerges as a compelling candidate for anode materials due to its exceptional combination of high theoretical specific capacity (1541.36 mAh/g) and a low average operating voltage (0.50 V). This translates to a remarkable energy density of 2882.34 mWh/g (referenced against the standard hydrogen electrode potential), making it a strong contender for next-generation battery technologies. Furthermore, our investigation revealed rapid diffusion barriers for Mg-ion migration with exceptional properties with robust compatibility with electrolytes, makes it anode materials for Mg-ion batteries, attracting significant interest in the near future.

Synthesis of Plasma-Reduced Graphene Oxide/Lithium Titanate Oxide Composite and Its Application as Lithium-Ion Capacitor Anode Material

A plasma-reduced graphene oxide/lithium titanate oxide (PrGO/LTO) composite is prepared as an anode material to enhance the performance of lithium-ion capacitors (LICs). The PrGO/LTO composite is synthesized by mixing graphene oxide (GO) and LTO, followed by a series of freeze-drying and plasma-treatment processes. PrGO forms a porous three-dimensional (3D) structure with a large surface area, effectively preventing the restacking of PrGO while covering LTO. The GO/LTO mixing ratio is controlled to optimize the final structure for LIC applications. In lithium-ion half-cell assembly, the PrGO/LTO-based anode with an 80% mixing ratio exhibits the highest specific capacity of 73.0 mAh g−1 at 20 C. This is attributed to the optimized ratio for achieving high energy density from LTO and high power density from PrGO. In a LIC full-cell comprising PrGO/LTO as the anode and activated carbon as the cathode, the energy and power densities at 1 A g−1 are 40.3 Wh kg−1 and 2000 W kg−1, respectively, with a specific capacitance of 36.3 F g−1 and capacitance retention of 94.1% after 2000 cycles. Its outstanding performance, obtained from incorporating 3D-structured PrGO with LTO at an optimized ratio, lowers the cell resistance and provides efficient lithium-ion diffusion pathways.

Electrospun metal-organic framework materials derived bimetallic oxides as high-efficiency anodes for lithium-ion battery

Energy devices are receiving more and more attention, and this is especially true for lithium-ion batteries. Moreover, applying novel nanostructures in multicomponent systems is a very effective way to promote the development of energy storage systems. This study synthesizes a nitrogen-doped carbon nanofiber encapsulating MOF-derived bimetallic oxide nanomaterial by combining electrospinning and MOF materials. Nitrogen-doped carbon nanofibers are porous and highly conductive, providing structural stability, a practical pathway for lithium ion diffusion, and an essential channel for rapid charge transfer during cycling. The bimetallic oxides derived from the MOF materials provide sufficient space for fast reaction sites and mitigate volume expansion during cycling. When the composite material FNO@NCNFs is used as the anode material for lithium batteries, its reversible capacity is maintained at 1105.4 mAh g−1 after 100 cycles at a current density of 0.1 A g−1. Its capacity reaches 748.5 mAh g−1 after 900 cycles at a current density of 1 A g−1, and at the same time, it exhibits excellent cycling stability, with the coulombic efficiency remaining above 98 %. The material also exhibits a small ion transfer resistance and good rate performance. The structural design approach based on combining MOFs with electrospinning in this study will provide new insights into the design and development of materials for advanced energy storage applications.

Superior electrochemical performances of Lithium vanadium oxide with coconut shell-based porous carbon as the anode of the aqueous Li ion battery

Carbon materials, as the skeleton structure of electrode materials, are composited with lithium-ion anode materials, which not only increase the electrical conductivity of the materials, but also enhance the electrochemical performance of the electrode materials. In this paper, LiV3O8@C composites were prepared by using coconut shell-based porous carbon to structurally modulate aqueous lithium-ion anode materials. And three composites with different structures and sizes were successfully synthesized by hydrothermal method, hydrothermal stirring method and improved solid-phase method. After XRD and SEM analyses, it was found that all three composites maintained the monoclinic crystal system structure of LiV3O8, and the materials prepared by the hydrothermal method showed a smooth layer structure, while the materials prepared by the hydrothermal stirring method and the solid-phase method showed nanorods with different sizes. The prepared anode materials and LiFePO4 cathode materials were assembled into an aqueous lithium-ion full battery, and were subjected to charge/discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy. The results indicate that the electrochemical performances of the three composites are significantly improved compared with the pure LiV3O8. Specifically, the discharge capacities of the two groups of nanorod-like composites were 112.2 mAh/g and 85.5 mAh/g at a rate of 0.2 C, which were improved by as much as two times compared with the pure LiV3O8. However, the composite material with layered structure not only reaches an initial discharge specific capacity of 148.39 mAh/g, which is 2.7 times higher than that of the pure LiV3O8, but also effectively slows down the dissolution effect of LiV3O8 by compositing with the carbon material, and at the same time, it shows excellent rate performance.

Comparative Investigation of Water-Based CMC and LA133 Binders for CuO Anodes in High-Performance Lithium-Ion Batteries.

Transition metal oxides are considered to be highly promising anode materials for high-energy lithium-ion batteries. While carbon matrices have demonstrated effectiveness in enhancing the electrical conductivity and accommodating the volume expansion of transition metal oxide-based anode materials in lithium-ion batteries (LIBs), achieving an optimized utilization ratio remains a challenging obstacle. In this investigation, we have devised a straightforward synthesis approach to fabricate CuO nano powder integrated with carbon matrix. We found that with the use of a sodium carboxymethyl cellulose (CMC) based binder and fluoroethylene carbonate additives, this anode exhibits enhanced performance compared to acrylonitrile multi-copolymer binder (LA133) based electrodes. CuO@CMC electrodes reveal a notable capacity ~1100 mA h g-1 at 100 mA g-1 following 170 cycles, and exhibit prolonged cycling stability, with a capacity of 450 mA h g-1 at current density 300 mA g-1 over 500 cycles. Furthermore, they demonstrated outstanding rate performance and reduced charge transfer resistance. This study offers a viable approach for fabricating electrode materials for next-generation, high energy storage devices.

Controllable Synthesis and Growth Mechanism of Cracked Cowpea-Like NCNT Encapsulated with Fe3N Nanoparticles for High-Performance Anode Material in Lithium-Ion Batteries

Fe3N nanocrystals embedded in cracked N-doped carbon nanotubes (Fe3N@NCNT) with a cowpea-like shape are innovatively prepared by metal-catalyzed graphitization and nitridization processes based on melamine and FeC2O4 precursor. The new in-situ synthesis strategy is proved to be effective to open the NCNT using a migratory metal carbide nanocatalyst via expansion effect and fabricate a metal nitride embedded NCNT with fully active ingredients. The detailed tip-growth mechanism of cracked NCNT with latitudinal-longitudinal graphene layers is studied by in-situ XRD analysis of the phase evolution of melamine and FeC2O4, and ex-situ SEM/TEM investigation of the topography correlation of NCNT and Fe3C floating catalyst. The Fe3N@NCNT microclews based anodes have a moderate carbon content of 35.45 wt%, electroactive NCNT conductive network, abundant microcracks and an open short-cavity system, showing a stable discharge capacity of 667 mAh g−1 at 0.1C, outstanding rate capability of 448 mAh g−1 at 5C and remarkable long-term cycling stability of 546 mAh g−1 after 600 cycles at 1C. The combined good electronic/ionic conductivity of cracked NCNT and robust mechanical stability of geometrically confined Fe3N nanoparticles contribute to the excellent redox activities, stabilized solid-electrolyte-interphase film and cycling durability of Fe3N@NCNT.

Improving the performance of glucose oxidase biofuel cell by methyl red and chitosan composite electrodes

This research aims to improve the output power of self-pumping glucose enzymatic biofuel cell (EBFC) and modifying the anode. Adding a fixed ratio of methyl red-chitosan (MR-CS) can effectively improve the EBFC efficiency and stability. In addition, chitosan can be obtained from discarded crustacean fishery waste objects such as shrimp and oysters, are also significant to the use of environmentally friendly materials. The catalyst was immobilized on pyrenecarboxaldehyde (PCA), polyethyleneimine (PEI) and multi-wall carbon nanotubes (MWCNT) and combined with glucose oxidase (GOx). Finally, the [PCA/GOx]/PEI/Nafion solution/MWCNT/[MR-CS] catalyst was immobilized on the carbon cloth. Experimental analysis was progressed under the preparation of enzyme-supported electrode to observe the feasibility of the anode electrode. Experiment including Fourier transform infrared spectroscopy (FTIR) to analyze the distribution of functional groups after modification of the carbon cloth electrode, and through the comparison of the ultraviolet–visible spectrometer (UV–Vis), it can be known that the concentration ratio of [MR-CS] is 1:5, the glucose oxidase load can be maximized. Electrochemical analysis (Cyclic Voltammetry, CV) measures the activity of the maximum reaction of the anode material and the corresponding redox peak, and scanning electron microscope (SEM) observes the surface morphology of the modified electrode. Self-pumping glucose enzymatic biofuel cell module was assembled and examined, the results showed that the maximum output power density (MPD) was 2.64 mW/cm2.

Lithiophilic Reduced Graphene Oxide/Carbonized Zeolite Imidazolate Framework-8 Composite Host for Stable Li Metal Anodes.

Lithium (Li) metal is regarded as a next-generation anode material owing to its high energy density. However, issues such as dendritic growth and volume changes during charging and discharging pose significant challenges for commercialization. We propose using lithiophilic reduced graphene oxide (rGO) and carbonized zeolite imidazolate framework-8 (C-ZIF-8) composites as host materials for Li to address these problems. The rGO/C-ZIF-8 composites are synthesized through a simple redox reaction followed by carbonization and are characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The roles of chemical composition, characteristics, and morphology are demonstrated. As a result of these favorable structural and functional properties, the Li symmetric cell with rGO/C-ZIF-8 exhibits a stable voltage profile for more than 100 h at 1 mA cm-2 without short-circuiting. A relatively low Li plating/stripping overpotential of ~101.5 mV at a high current density of 10 mA cm-2 is confirmed. Moreover, a rGO/C-ZIF-8-Li full cell paired with a LiFePO4 cathode demonstrates good cyclability and rate capability.

Carbon coating engineering enhances the stability of graphite anode in potassium ion batteries

Graphite forms reversible potassium-graphite intercalation compounds electrochemically. Graphite anode possesses a high reversible specific capacity (279 mAh g−1) and an optimal low potential platform, rendering it an ideal anode material for potassium-ion batteries. However, the intercalation of K+ ions in graphite causes a bulk volume expansion of up to 61%, resulting in irreversible damage to the structure of graphite, which leads to inferior cycling stability. In this paper, surface-oxidized graphite (OG) with reduced particle size and increased defect densities was obtained by mechanical ball milling and chemical oxidation. Composites of soft carbon-coated OG (OG@PC) were prepared by soft carbon coating. The soft carbon coating can alleviate the bulk expansion caused by K+ intercalation/deintercalation in OG, thus slowing down the destruction of the crystalline structure of graphite after multiple charging/discharging cycles. OG@PC exhibits increased reversible specific capacity from 267 mAh g−1 to 314 mAh g−1 compared with pristine graphite at a current density of 0.05 A g−1. Moreover, at a high current density of 0.5 A g−1, a reversible specific capacity of 213 mAh g−1 was achieved after 200 cycles. This work investigates simple surface carbon coating strategies to improve the cycling stability of a graphite anode of potassium-ion batteries.

Enhanced Li-ion battery performance based on multisite oxygen vacancies in WO3-x@rGO negative electrode

While transition-metal oxides have emerged as promising candidates for lithium energy storage, several issues are remained to be addressed such as low conductivity, rate performance, and recyclability. In this study, a three-dimensional interconnected sheet-like heterostructure of WO3-x coated with reduced graphene oxide (rGO) was synthesized using the hydrothermal method. This structure significantly enhanced the conductivity of WO3-x. By combining the heterojunction with oxygen vacancies (OV), the active sites are enlarged, promoting the effective movement of ions and electrons at the interface between the WO3-x and rGO. The prepared anode exhibits a high specific capacity of 1202.6 mAh/g at 0.1 A g−1, with a cycling retention rate of 96 % after 100 cycles. Meanwhile, even at 5 A g−1, it still maintains a capacity of 305 mAh/g after 500 cycles. Theoretical calculations reveal that the presence of the composite heterogeneous structure enables WO3-x@rGO to possess appropriate adsorption energy, lower work function, and reduced barriers. This arrangement provides abundant active sites, promoting the rapid penetration of the electrolyte and enhancing the interface reaction kinetics, which is consistent with the experimental results. This study offers a new strategy for Li-ion anode materials.

Electrochemical sodium storage properties in monolayer VOPO4: A density functional theory prediction

The unique structural properties of two-dimensional materials make them promising for energy storage applications. This work theoretically predicts for the first time that Monolayer VOPO4 (MNL VOPO4), exfoliated from the delithiated phase of tetragonal LiVOPO4, is stable at room temperature, exhibiting excellent thermodynamic and kinetic stability, thus making it a promising high-capacity anode material for sodium-ion batteries (SIBs). Compared to bulk VOPO4, the monolayer structure significantly reduces the sodium ion migration energy barrier from 1.006 to 0.0795 eV, thereby markedly enhancing sodium ion migration kinetics. MNL VOPO4 can adsorb up to 32 sodium ions, corresponding to a theoretical capacity of 634.88 mA h g−1 and an energy density of 895.18 Wh kg−1. Furthermore, the excellent structural stability of MNL VOPO4 favors its cycling performance during charge and discharge processes. This work provides theoretical insights for better utilizing and developing multi-atomic phosphate compounds as electrode materials for secondary batteries.

Two-dimensional Cu2N–A high-performance anode material for ion batteries with excellent electrical conductivity and electrolyte wettability

Determining suitable anode materials is crucial in the advancement of lithium-ion and sodium-ion battery technologies. We propose that the two-dimensional (2D) material Cu2N holds promise as a viable anode candidate. The Cu2N monolayer exhibits a stable checkerboard lattice crystal structure, ensuring structural integrity. Its excellent metallic electronic structure facilitates efficient conductivity during battery operation. We have observed that Li/Na ions can chemically bond to Cu2N substrates via specific charge exchange mechanisms. Moreover, the Cu2N monolayer demonstrates favorable wettability and compatibility with common electrolytes used in lithium-ion and sodium-ion batteries, including solvent molecules and metal salts. Our findings indicate that the Li/Na storage capacity of the Cu2N monolayer reaches approximately 760/760 mAh/g, surpassing that of graphite anodes significantly. Notably, the Li/Na diffusion barrier on the Cu2N monolayer is merely 5/13 meV, lower than that of most other 2D anode materials. Our results underscore the potential of the Cu2N monolayer as an outstanding electrode material, offering high storage capacity, rapid charge/discharge rates, and favorable wettability with electrolytes.

A Bandgap-Tuned Tetragonal Perovskite as Zero-Strain Anode for Potassium-Ion Batteries.

PIBs are emerging as a promising energy storage system due to high abundance of potassium resources and theoretical energy density, however, progress of PIBs is severely hindered by structural instability and poor cycling of anode material during continual insertion and extraction of larger-sized K+. Hence, developing anode material with structural stability and stable cycling remains a great challenge. Herein, bandgap-tuned Mo-doped and carbon-coated lead titanate (CMPTO) with zero-strain K+ storage is presented as ultra-stable PIBs anode. Mo doping introduces narrowed bandgap and optimized crystal lattice for enhanced intrinsic electron and ion transfer. Demonstrated by in situ XRD characterizations, the crystal structure stays stable with unchanged peak positions, fully revealing zero-strain characteristic of CMPTO anode during potassium storage for stable cyclic capability. Ultimately, CMPTO anode achieved ultra-stable cycling performance of 7000 cycles at 500 mA g-1 with high capacity retention of 90% and considerable specific capacity of 130.9 mAh g-1 after 600 cycles at 100 mA g-1; with relatively large density, CMPTO realized eminent volumetric capacity of 1111.09 mAh cm-3 and ultra-long cycling life of 10000 cycles at 7041 mA cm-3. This work introduces a promisingly new route into developing anode materials with ultra-stable performance for PIBs.

Hard carbon/graphene microfibers as a superior anode material for sodium-ion batteries

Hard carbon is one of the most promising anode materials for sodium-ion batteries (SIBs). However, it still suffers from low specific capacity and poor rate capability, which impede its practical application. Herein, one-dimensional hard carbon/graphene microfibers are synthesized by encapsulating hard carbon particles in graphene nanosheet using a wet-spinning technique followed by pyrolysis treatment. Benefiting from the unique structure, when used as the anode material for SIBs, the as-obtained hard carbon/graphene microfibers not only exhibit a high reversible capacity of 321 mAh g−1 at 0.1 C but also deliver long cycling stability and excellent rate capability, maintaining its capacity as 203 mAh g−1 even after 350 cycles at 1 C. In addition, the sodium storage mechanism of the as-prepared hard carbon/graphene microfibers is investigated by in-situ Raman technique. Moreover, a full cell adopting the hybrid microfiber as the anode and Na3V2(PO4)3 as the cathode exhibits high specific capacities of 291 mAh g−1 and 204 mAh g−1 at 0.2 C and 4 C (vs. anode), respectively. This work provides a sustainable and cost-effective strategy for the synthesis of high-capacity and stable hard carbon anode materials.

A Review of Carbon Nanofiber Materials for Dendrite-Free Lithium-Metal Anodes.

Lithium metal is regarded as ideal anode material due to its high theoretical specific capacity and low electrode potential. However, the uncontrollable growth of lithium dendrites seriously hinders the practical application of lithium-metal batteries (LMBs). Among various strategies, carbon nanofiber materials have shown great potential in stabilizing the lithium-metal anode (LMA) due to their unique functional and structural characteristics. Here, the latest research progress on carbon nanofibers (CNFs) for LMA is systematically reviewed. Firstly, several common preparation techniques for CNFs are summarized. Then, the development prospects, strategies and the latest research progress on CNFs for dendrite-free LMA are emphatically introduced from the perspectives of neat CNFs and CNF-based composites. Finally, the current challenges and prospects of CNFs for stabilizing LMA are summarized and discussed. These discussions and proposed strategies provide new ideas for the development of high-performance LMBs.