Anode Material For Lithium-ion Batteries Research Articles

CoO nanocrystals dispersed in N-doped carbon networks as enhanced anode for lithium storage

CoO emerges as a promising anode material for lithium-ion batteries (LIBs) because of high theoretical specific capacity and rich resource. However, its practical application is impeded by significant volume expansion and poor electrical conductivity during the charging and discharging cycles. Herein, we construct a nanocomposite of CoO nanocrystals and N-doped carbon serving as an enhanced anode for LIBs by a facile strategy. In the nanocomposite, CoO nanocrystals with average size of 60 nm uniformly were dispersed in N-doped carbon networks. The synergy effects of CoO nanocrystals and N-doped carbon networks can extremely enhance electronic conductivity, relieve volume expansion, and effectively protect CoO nanocrystals from aggregating. Hence, the composite anode delivers large reversible capacity (1190 mAh g−1 at 0.3 A g−1 after 100 cycles), remarkable rate capability (592 mAh g−1 at 5 A g−1), and long cycling ability. This offers a simple approach for designing high-performance anodes for LIBs.

Studies on highly stable Na7Fe3(P2O7)4 as anode materials for lithium-ion batteries and migration behavior of lithium ions

In this paper, Na7Fe3(P2O7)4 target material is firstly evaluated as potential anode material for lithium ion batteries. It is found to have good electro-chemical performance and high stability as anode material for lithium batteries. It shows a capacity of 290 mAh g−1 for 200 cycles and increases to 388 mAh g−1 for 1000 cycles at a current density of 150 mA g−1. The Coulomb efficiency is maintained at about 98 % during the long cycling. The ex-situ experimental results indicate that Na7Fe3(P2O7)4 has high structural stability and the changes of cell volume and cell parameters are <0.62 % during charging and discharging. The results of GITT data show that the diffusion coefficients range from 3.15 × 10−11 cm2 S−1 to 1.12 × 10−12 cm2 S−1.The Li+/Na+ diffusion paths are estimated by the Bond valence-energy landscape (BEL) method and the exact energy barriers and minimal energy paths (MEPs) are determined using the nudged elastic band (NEB) method implemented in density functional theories (DFT). A two dimensional Na+ diffusion network is observed and Na+ diffusion along c-axis is prohibited. For the initial discharge stage, Na+ migrates in the Na+ transportation channel with an energy barrier of 0.48 eV along a-axis and 0.46 eV along b-axis. For the discharge later on, the intercalated Li+ enters the nearby Na+ vacancies and also migrate in the Na+ channel except Li+ at 8f Lid sites, which will stay where it is firstly introduced because of the higher energy barrier of 0.75 eV. The immobility of Lid is one of the important reasons for the irreversible capacity loss after the initial charge/discharge cycle.

Comparison of different elastic strain definitions for largely deformed SEI of chemo-mechanically coupled silicon battery particles

Amorphous silicon is a highly promising anode material for next-generation lithium-ion batteries. Large volume changes of the silicon particle have a critical effect on the surrounding solid-electrolyte interphase (SEI) due to repeated fracture and healing during cycling. Based on a thermodynamically consistent chemo-elasto-plastic continuum model we investigate the stress development inside the particle and the SEI. Using the example of a particle with SEI, we apply a higher order finite element method together with a variable-step, variable-order time integration scheme on a nonlinear system of partial differential equations. Starting from a single silicon particle setting, the surrounding SEI is added in a first step with the typically used elastic Green–St-Venant (GSV) strain definition for a purely elastic deformation. For this type of deformation, the definition of the elastic strain is crucial to get reasonable simulation results. In case of the elastic GSV strain, the simulation aborts. We overcome the simulation failure by using the definition of the logarithmic Hencky strain. However, the particle remains unaffected by the elastic strain definitions in the particle domain. Compared to GSV, plastic deformation with the Hencky strain is straightforward to take into account. For the plastic SEI deformation, a rate-independent and a rate-dependent plastic deformation are newly introduced and numerically compared for three half cycles for the example of a radial symmetric particle.

Hollow Cobalt Selenide-Carbon polyhedron sandwiched between reduced graphene oxide nanosheets: A superior anode material for lithium-ion batteries

In this work, a double carbon-confined sandwich-like CoSe/NCP/rGO composite was fabricated using an self-assembled method combined with a selenization treatment. In the composite, cobalt selenide (CoSe) nanoparticles were embedded in N‑doped hollow carbon polyhedrons (NCP) and sandwiched between reduced graphene oxide (rGO) nanosheets. The kinetics of electron/ion transport along with the structural stability of the composite were significantly enhanced by the layer-by-layer sandwiched hollow structure and the strong cohesive interface interaction between various components. The CoSe/NCP/rGO, when serving as LIB’s anode material, exhibited excellent performance. It demonstrated a high specific capacity with the value of 843 mAh/g at 1 A/g, superior high-rate capability with capacity remaining at 309 mAh/g at 10 A/g, long-term cycling stability with no noticeable capability fading over 1000 loops. More importantly, these results were achieved without additional conductive agents.

A Review of Nanocarbon-Based Anode Materials for Lithium-Ion Batteries

Renewable and non-renewable energy harvesting and its storage are important components of our everyday economic processes. Lithium-ion batteries (LIBs), with their rechargeable features, high open-circuit voltage, and potential large energy capacities, are one of the ideal alternatives for addressing that endeavor. Despite their widespread use, improving LIBs’ performance, such as increasing energy density demand, stability, and safety, remains a significant problem. The anode is an important component in LIBs and determines battery performance. To achieve high-performance batteries, anode subsystems must have a high capacity for ion intercalation/adsorption, high efficiency during charging and discharging operations, minimal reactivity to the electrolyte, excellent cyclability, and non-toxic operation. Group IV elements (Si, Ge, and Sn), transition-metal oxides, nitrides, sulfides, and transition-metal carbonates have all been tested as LIB anode materials. However, these materials have low rate capability due to weak conductivity, dismal cyclability, and fast capacity fading owing to large volume expansion and severe electrode collapse during the cycle operations. Contrarily, carbon nanostructures (1D, 2D, and 3D) have the potential to be employed as anode materials for LIBs due to their large buffer space and Li-ion conductivity. However, their capacity is limited. Blending these two material types to create a conductive and flexible carbon supporting nanocomposite framework as an anode material for LIBs is regarded as one of the most beneficial techniques for improving stability, conductivity, and capacity. This review begins with a quick overview of LIB operations and performance measurement indexes. It then examines the recently reported synthesis methods of carbon-based nanostructured materials and the effects of their properties on high-performance anode materials for LIBs. These include composites made of 1D, 2D, and 3D nanocarbon structures and much higher Li storage-capacity nanostructured compounds (metals, transitional metal oxides, transition-metal sulfides, and other inorganic materials). The strategies employed to improve anode performance by leveraging the intrinsic features of individual constituents and their structural designs are examined. The review concludes with a summary and an outlook for future advancements in this research field.

Carbon-Based 3D Architectures as Anodes for Lithium-Ion Battery Systems.

Graphite, with its exceptional cyclic performance, continues to dominate as the preferred anode material for lithium-ion batteries. However as high-energy application gains momentum, there is growing demand for higher capacities that alloying/de alloying and conversion type anode materials can offer. Despite their potential, these materials are plagued by challenges such as volumetric fluctuations, low conductivities, and poor cyclic stability. Carbon nanostructures, on the other hand, show tremendous promise with their low volume expansion, high ion diffusion rates, and excellent conductivity. Nevertheless, their limited areal and volumetric densities restrict their widespread utilization. To address these limitations, various strategies such as doping, composite formation, and structural modification have been proposed. This article provides a succinct overview of carbon nanomaterials and their electrochemical performance as 3D carbon-based anodes, along with a comprehensive analysis of the strategies employed to overcome associated challenges while evaluating their potential prospects in the field.

Novel binder-free vanadium-based molten salt (NMPV) with low-cost as anode materials of lithium-ion batteries

Molten salt NMPV material is synthesised using a one-step method and applied to binder-free anodes for lithium-ion batteries (LIBs). In this work, simple, low-cost and highly active coordination molten salt electrode materials (NMPV and NMPV-C) were prepared, which overcame the drawbacks of cumbersome and costly preparation of the existing electrode materials. NMPV is formed by the lone pair of electrons of N-methyl pyrrolidone (NMP) molecules coordinated with vanadium ion. The synergistic effect produced by these two and the excellent electrical conductivity and electrochemical properties of the molten salt material itself exhibits satisfactory lithium storage results. The discharge capacities of NMPV-C and NMPV in the second discharge cycle are 669 and 345 mAh g−1, respectively. After 100 cycles, the capacity is maintained at 923 and 549 mAh g−1, respectively. And the capacity retention is 137.97 % and 159.13 %, respectively. In addition, the NMPV-C electrode maintains a stable reversible capacity of 450 mAh g−1 at 2000 mAh g−1 after 220 cycles. Density-functional theory (DFT) calculations revealed that Li+ is more likely to attack H on methyl nitrogen, which is the optimal reaction site for NMPV since the lone pair of electrons of N effectively stabilises the carbon cation after the reaction of Li with H.

Effects of size and shape of hole defects on mechanical properties of biphenylene: a molecular dynamics study

The distinctive multi-ring structure and remarkable electrical characteristics of biphenylene render it a material of considerable interest, notably for its prospective utilization as an anode material in lithium-ion batteries. However, understanding the mechanical traits of biphenylene is essential for its application, particularly due to the volumetric fluctuations resulting from lithium ion insertion and extraction during charging and discharging cycles. In this regard, this study investigates the performance of pristine biphenylene and materials embedded with various types of hole defects under uniaxial tension utilizing molecular dynamics simulations. Specifically, from the stress‒strain curves, we obtained key mechanical properties, including toughness, strength, Young's modulus and fracture strain. It was observed that various near-circular hole (including circular, square, hexagonal, and octagonal) defects result in remarkably similar properties. A more quantitative scaling analysis revealed that, in comparison with the exact shape of the defect, the area of the defect is more critical for determining the mechanical properties of biphenylene. Our finding might be beneficial to the defect engineering of two-dimensional materials.

Two-dimensional BC12 as an ultra-high performance anode material for lithium-ion batteries

With the gradual development of renewable energy, search for high-performance energy storage materials as anodes for lithium-ion batteries (LIBs) has become urgent. Two-dimensional (2D) materials are considered as candidates for anode materials due to their unique structure and physicochemical properties. Based on first-principles calculations, we propose a 2D material, BC12 monolayer, as an excellent anode for LIBs. BC12 exhibits outstanding dynamic, mechanical, and thermal stability. In addition, BC12 monolayers show not only remarkably high storage capacity (2767.57 mA h g−1) but also low diffusion barrier energy (0.175 eV) and appropriate open circuit voltage (0.3 V). A small volume expansion (0.38%) is also observed during the lithiation process. Furthermore, we undertake a comprehensive analysis on the impact of carbon vacancy in BC12. The presence of carbon vacancy makes the adsorption and diffusion of Li relatively weak, which should be carefully handled in the experimental synthesis process. The above-mentioned investigation offers valuable insights and guidance for the future development and application of 2D anode materials in metal-ion batteries.

Innovative Tin and hard carbon architecture for enhanced stability in lithium-ion battery anodes

Tin (Sn), with a theoretical capacity of 994 mAh g-1, is a promising anode material for lithium-ion batteries (LIBs). However, fundamental limitations like large volume expansion during charge-discharge cycle and confined electronic conductivity limit its practical utility. Here, we report a new material design and manufacturing method of LIB anodes using Sn and Hard Carbon (HC) architecture, which is produced by Physical Vapor Deposition (PVD). A bilayer HC/Sn anode structure is deposited on a carbon/copper sheet as a function of deposition time, temperature, and substrate heat treatment. The developed anodes are used to make cells with a lithium-ion electrolyte using a specific fabrication process. The morphology, atomic structure, conductivity, and electrochemical performance of the developed HC/Sn anodes are studied with SEM, TEM, XPS, and electrochemical techniques. At a discharge rate of 0.1C, the Snheated + HC anode performs exceptionally well, offering a capacity of 763 mAh g-1. It is noteworthy that it achieves a capacity of 342 mAh g-1 when fast charging at 5C, demonstrating exceptional rate capability. The Snheated + HC anode maintains >97 % Coulombic efficiency of its capacity after 3000 cycles at a rate of 0.1C after 3000 cycles 730.5 mAh g-1 recorded, demonstrating an impressive cycle life. The novel material design approach of the Snheated + HC anode, which has a multi-layered structure and HC acting as a barrier against volumetric expansion and improving electronic conductivity during battery cycling, is perceived as influential in uplifting anode's performance.

Small‐Molecule Polycyclic Aromatic Hydrocarbons as Exceptional Long‐Cycle‐Life Li‐Ion Battery Anode Materials

The growing demand for cost‐effective and sustainable energy‐storage solutions has spurred interest in novel anode materials for lithium‐ion batteries (LIBs). In this study, the potential of small‐molecule polycyclic aromatic hydrocarbons (SMPAHs) as promising candidates for LIB anodes is explored. Through a comprehensive experimental approach involving electrode fabrication, material characterization, and electrochemical testing, the electrochemical performance of SMPAHs, including naphthalene, biphenyl, 9,9‐dimethylfluorene, phenanthrene, p‐terphenyl, and pyrene (Py), is thoroughly investigated. In the results, the impressive cycle stability, high specific capacity, and excellent rate capability of the SMPAH electrode are revealed. Additionally, a direct contact prelithiation strategy is implemented to enhance the initial Coulombic efficiency (ICE) of SMPAH anodes, yielding significant improvements in the ICE and cycle stability. Computational simulations provide valuable insights into the electrochemical behavior and lithium‐storage mechanisms of SMPAHs, confirming their potential as effective anode materials. The simulations reveal favorable lithium adsorption sites, the predominant storage mechanisms, and the dissolution mechanism of Py through computational calculations. Overall, in this study, the promise of SMPAHs is highlighted as sustainable anode materials for LIBs, advancing energy‐storage technologies toward a greener future.

Amide coupled Si-rGO hybrids as anode material for lithium-ion batteries

Despite silicon (Si) having a high specific capacity of 4200 mA h/g, it undergoes significant expansion in volume during lithiation. In order to alleviate the significant increase in volume that occurs in silicon nanoparticles (SiNPs) of lithium-ion batteries, herein we report covalently modified SiNP contained within reduced graphene oxide (rGO) sheets as an anode material in lithium-ion batteries (LIBs). The structural modification of SiNP could effectively mitigate the increase in volume while preserving its outstanding electrochemical properties. Graphene oxide (GO) undergoes chemical modification and functionalization by a simple and efficient method using microwave-assisted sonochemical approach. The procedure entails grafting carboxyl functionalized silicon nanoparticles (C-Si) to amine-functionalized reduced graphene oxide (NH2-rGO) to produce a Si-rGO hybrid via amide linkage. This hybrid reduces the problem of volume expansion in Si anodes by dissipating substantial changes in volume and minimizing direct contact between SiNPs and the electrolyte. The formation of a robust solid electrolyte interface (SEI) layer improves the specific capacity and durability of the anode material. We observed that the Si-rGO 2 hybrid (containing 44 wt% Si) exhibited a relatively higher specific capacity of 1604 mA h/g during the initial cycle at C/10 rate when compared to other hybrid systems, such as Si-rGO 1, Si-rGO 2, Si-rGO 3 with bare SiNP, and SRGO composite (without amide linkage). Additionally, it maintained a capacity of approximately 1000 mA h/g at C/2 rate for more than 125 cycles. Thus, enhanced specific capacity, cycling stability, electrode conductivity, and lithiation are made possible due to the structural modification of SiNPs.

Silicon/graphite/amorphous carbon composites as anode materials for lithium-ion battery with enhanced electrochemical performances

Silicon has emerged as one of the most promising anode materials for next-generation lithium-ion batteries due to its exceptional specific capacity and abundant resources. However, its widespread application is hindered by structural deformability and low intrinsic conductivity. By strategically integrating a conductive carbon matrix with silicon, it becomes feasible and efficient to enhance the electrical conductivity of silicon and accommodate the stress-induced volume expansion during battery operation. In this study, a series of silicon/graphite/amorphous carbon (Si/G/C) composites were prepared using mechanical milling and carbothermal reduction. The study focused on two main aspects: the effect of the ratio of micro-sized silicon to flake graphite on the properties of the composite and the compatibility of different-scale silicon particles (micro-sized silicon and nano-sized silicon) and different kinds of natural graphite (flake graphite and cryptocrystalline graphite). The results reveal that when micro-sized silicon and flake graphite are combined, the graphite is fragmented more thoroughly, resulting in smoother surfaces and reduced aggregation of secondary particles. The composites with a mass ratio of 7:3 micro-sized silicon to flake graphite have the smallest specific surface area and pore size, homogeneous distribution, and stable structure. This exceptional carbon-to-silicon ratio endows the Si/G/C composite with rapid reaction kinetics, enabling a specific discharge capacity of 854.1 mAh g-1 after 200 cycles at 1A g-1. The findings offer valuable insights into the design and optimization of silicon-based anode materials for next-generation lithium-ion batteries.

Novel metal-organic anode material by in-situ chelating Ni2+ with tannic acid on carbon nanotube for high-performance Li storage

Lithium-ion batteries (LIBs) with natural organic anode are attracting intensive interest for application owing to their structural diversity, cost-effectiveness, eco-friendliness, and high specific capacity. However, directly usage of natural organic materials as anode materials usually encounters poor electrochemical properties such as low reversible capacity and short cycling life. Thus, developing high-performance organic electrode materials for LIBs remains a great challenge. Herein, we present a rational design and fabrication of TA-Ni@CNTs by in-situ coating TA-Ni polymers onto the surface of carbon nanotubes (CNTs) as a superior anode material for LIBs. Specifically, the highly conductive CNTs can effectively relieve the aggregation of TA-Ni and improve the electronic conductivity. Meanwhile, the strong chelation among nickel irons and catechol groups enhances the structure stability and inhibits the dissolving property. Consequently, as an anode material for LIBs, the resulting TA-Ni@CNTs achieves a high reversible capacity of 1418.8 mAh·g−1 at 0.1 A·g−1 after 216 cycles and an outstanding cycling stability with 951.1 mAh·g−1 at 0.5 A·g−1 after 323 cycles. The presented design strategy holds great promise for developing more-efficient electrode materials for LIBs.

Constructing a 3D Li[sbnd]Mg alloy skeleton through mechanical rolling for high-rate Li anodes

Li is a promising anode material for lithium-ion batteries owing to its low redox potential (−3.04 V vs. standard hydrogen electrode) and exceptionally high theoretical specific capacity (3860 mAh g−1). However, considerable volume changes and uncontrolled dendrite growth reduce coulombic efficiency during charge/discharge cycles, limiting its practical application. This research introduces a straightforward method to fabricate a two-phase intertwined composite electrode featuring a LiMg phase as a three-dimensional (3D) skeleton structure aimed at high-rate Li-metal batteries. With its mixed electronic and ionic conducting networks, the 3D alloy structure offers abundant interfaces with pure Li and exhibits strong lithium affinity, enhancing Li+ diffusion throughout the electrode and enabling dendrite-free deposition. Results demonstrate a long cycle life exceeding 80 h at 30 mA cm−2 in symmetric cells. Coin- and pouch-type full cells with cathodes also show excellent rate capacity and cycling stability. The exceptional performance of this material makes it a highly desirable anode for high-rate lithium-metal batteries.

Large-Scale Synthesis of N,S Codoped Carbon-Modified Fe0.975S Composites as a Novel Anode for Lithium/Sodium Ion Batteries with Enhanced Performance.

To overcome obstacles hindering the commercialization of lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs), we introduce a cost-effective single-step sulfurization strategy for synthesizing iron sulfide (Fe0.975S) nanohybrids, augmented by N,S codoped carbon. The resulting N,S codoped carbon-coated Fe0.975S (Fe0.975S@NSC) electrode exhibits exceptional potential as a highly reversible anode material for both LIBs and SIBs. With impressive initial discharge and charge capacities (1658.2 and 1254.9 mAh g-1 for LIBs and 1450.9 and 1077.1 mAh g-1 for SIBs), the electrode maintains substantial capacity retention (900 mA h g-1 after 1000 cycles for LIBs and 492.5 mA h g-1 after 600 cycles for SIBs at 1.0 A g-1). The LiMn2O4//Fe0.975S@NSC and Na3V2(PO4)3//Fe0.975S@NSC full batteries can maintain excellent reversible capacity and robust cycling stability. Ex situ and in situ X-ray diffraction, density functional theory (DFT) calculations, and kinetics analysis confirm the promising energy storage potential of the Fe0.975S@NSC composite.

A Bifunctional Carbon-LiNO3 Composite Interlayer for Stable Lithium Metal Powder Electrodes as High Energy Density Anode Material in Lithium Batteries

Lithium metal remains a promising candidate for high-energy-density rechargeable batteries due to its exceptional specific capacity and low reduction potential. However, practical implementation of lithium metal anodes faces challenges such as dendrite formation, limited cycle life, and safety concerns. This study introduces a novel approach to enhance the performance of lithium metal powder (LMP)-based electrodes by embedding a LiNO3-carbon composite interlayer between the LMP electrode and the copper foil current collector. The N-rich carbon interlayer acts as a reservoir for LiNO3, enabling its gradual release to maintain prolonged stability of the interfacial reactions of the Li-metal and providing additional Li nucleation sites. Our findings demonstrate that the LiNO3-carbon composite effectively suppresses dendrite formation, improves reversible capacity, and stabilizes the solid electrolyte interphase. Additionally, we validated the fast-charging capabilities of the Li/NCM622 half-cell employing the LiNO3-carbon-coated Cu foil with LMP electrodes. Our results highlight the significant synergistic effect of the LiNO3 additive and carbon interlayer in enhancing the performance of lithium metal-based batteries.

Microfluidic Shape Analysis of Non-spherical Graphite for Li-Ion Batteries via Viscoelastic Particle Focusing.

The size and shape of graphite, which is a popular active anode material for lithium-ion batteries (LIBs), significantly affect the electrochemical performance of LIBs and the rheological properties of the electrode slurries used in battery manufacturing. However, the accurate characterization of its size and shape remains challenging. In this study, the edge plane of graphite in a cross-slot microchannel via viscoelastic particle focusing is characterized. It is reported that the graphite particles are aligned in a direction that shows the edge plane by a planar extensional flow field at the stagnation point of the cross-slot region. Accurate quantification of the edge size and shape for both spheroidized natural and ball-milled graphite is achieved when aligned in this manner. Ball-milled graphite has a smaller circularity and higher aspect ratio than natural graphite, indicating a more plate-like shape. The effects of these differences in graphite shape and size on the rheological properties of the electrode slurry, the structure of the coated electrodes, and electrochemical performance are investigated. This method can contribute to the quality control of graphite for the mass production of LIBs and enhance the electrochemical performance of LIBs.

Understanding the Effect of Lithium Nitrate as Additive in Carbonate-Based Electrolytes for Silicon Anodes

Due to its high specific capacity, silicon is one of the most promising anode materials for next-generation lithium-ion batteries. However, its large volumetric changes upon (de)lithiation of ∼300% lead to a rupture/re-formation of the solid-electrolyte interphase (SEI) upon cycling, resulting in continuous electrolyte consumption and irreversible loss of lithium. Therefore, it is crucial to use electrolyte systems that form a more stable SEI that can withstand large volume changes. Here, we investigate lithium nitrate (LiNO3) and lithium nitrite (LiNO2) as electrolyte additives. Linear scan voltammetry on carbon black working electrodes in a half-cell configuration with LiNO3-containing 1 M LiPF6 in EC/DEC (1/2 v/v) revealed a two-step reduction mechanism, whereby the first reduction peak could be attributed to the conversion of LiNO3 to LiNO2, while X-ray photoelectron spectroscopy on harvested electrodes suggests the formation of Li3N during the second reduction peak. On-line electrochemical mass spectrometry (OEMS) on carbon black electrodes showed that N2O gas is evolved upon the reduction of LiNO3- and LiNO2-containing electrolytes but that the gassing associated with EC reduction is significantly reduced. Furthermore, OEMS and voltammetry were used to examine the redox chemistry of LiNO2 additive. Finally, LiNO3 and LiNO2 additives significantly improved the cycle-life of Si||NCM622 full-cells.

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