Anode Material For Lithium-ion Batteries Research Articles

Effects of the oxyfluorination of needle coke-based anode materials on the capacities and stabilities of lithium-ion batteries

Needle cokes have emerged as an alternative anode material to graphite due to their high rate performance and cost advantages. Herein, we introduced oxygen and fluorine functional groups to increase the capacity and increase the cycling stability, respectively. Oxyfluorination was used to simultaneously introduce these two heterogeneous elements, and their effective introduction was quickly confirmed at room temperature. Compared with those of pristine needle coke-based lithium-ion batteries, the capacities of the lithium-ion batteries based on oxyfluorinated needle cokes increased by 17.9%, and the cycling stabilities of the modified batteries exceeded 92%. Therefore, introducing oxygen and fluorine functional groups into needle cokes through oxyfluorination is a viable strategy for producing anode materials for lithium-ion batteries with high rates and capacities.

NiCo Nanoparticles Encapsulated in Nitrogen-Doped Carbon Tubes as Anode Materials for High-Performance Lithium-Ion Batteries

NiCo Nanoparticles Encapsulated in Nitrogen-Doped Carbon Tubes as Anode Materials for High-Performance Lithium-Ion Batteries

Fabrication of a Stable and Highly Effective Anode Material for Li-Ion/Na-Ion Batteries Utilizing ZIF-12.

Transition metal selenides (TMSs) are receiving considerable interest as improved anode materials for sodium-ion batteries (SIBs) and lithium-ion batteries (LIBs) due to their considerable theoretical capacity and excellent redox reversibility. Herein, ZIF-12 (zeolitic imidazolate framework) structure is used for the synthesis of Cu2Se/Co3Se4@NPC anode material by pyrolysis of ZIF-12/Se mixture. When Cu2Se/Co3Se4@NPC composite is utilized as an anode electrode material in LIB and SIB half cells, the material demonstrates excellent electrochemical performance and remarkable cycle stability with retaining high capacities. In LIB and SIB half cells, the Cu2Se/Co3Se4@NPC anode material shows the ultralong lifespan at 2000 mAg-1, retaining a capacity of 543 mAhg-1 after 750 cycles, and retaining a capacity of 251 mAhg-1 after 200 cycles at 100 mAg-1, respectively. The porous structure of the Cu2Se/Co3Se4@NPC anode material can not only effectively tolerate the volume expansion of the electrode during discharging and charging, but also facilitate the penetration of electrolyte and efficiently prevents the clustering of active particles. In situ X-ray difraction (XRD) analysis results reveal the high potential of Cu2Se/Co3Se4@NPC composite in building efficient LIBs and SIBs due to reversible conversion reactions of Cu2Se/Co3Se4@NPC for lithium-ion and sodium-ion storage.

Theoretical prediction on Irida-graphene monolayer as promising anode material for lithium-ion batteries

With the growing interest in energy storage technologies, the demand for alternative rechargeable batteries has become increasingly urgent. We evaluate the feasibility of a two-dimensional (2D) material, Irida-graphene (IG) monolayer, as an anode for lithium-ion batteries (LIBs) through first-principles calculations. IG monolayer, after Li adsorption, exhibits metallic property, suggesting the good electrical conductivity. Additionally, in comparison with IG bilayer, IG monolayer possesses low diffusion barriers (0.19–0.24 eV), high theoretical capacity (1115.8mA h/g), and low average open circuit voltage (0.317 V). Furthermore, under the influence of solvent effects, the adsorption performance becomes even more stable, and the theoretical capacity increases. These intriguing findings make IG monolayer great potentials for the anode of LIBs.

Metal alkoxides: A new type of reversible anode materials for stable and high-rate lithium-ion batteries

Metal-organic compounds have attracted significant attention for lithium-ion battery (LIB) anodes. However, their practical application is severely hindered by the poor structural stability and sluggish Li+ reaction kinetics. Herein, we proposed a new type of metal–organic compound, metal alkoxides, for high-performance LIBs. A series of metal-alkoxide/graphene composites with different transition metal centers and alkoxide anions are prepared to investigate the structural stability, Li-storage ability, and Li+ diffusion kinetics. The results reveal that the metal centers and alkoxide anions have significant influence on the structural stability, molar mass, and electronic structures, which are highly related to the Li-storage performance. Among them, Co-EG/rGO (EG represents the ethylene glycol anion) delivers the best performance involving high specific capacity (975 mAh g−1 at 0.2 A g−1), excellent rate capability (400.8 mAh g−1 at 10 A g−1), and stable cycling performance (86.8 % capacity retention after 600 cycles) due to its stable structure, smaller molar mass, and favorable electronic structure. Moreover, the Li-storage mechanism and solid electrolyte interphase (SEI) evolution of the Co-EG/rGO electrode are studied in detail through multiple ex-situ/in-situ characterizations. This work provides a new type of metal alkoxide anode material for high-rate and long-life LIBs toward practical energy applications.

PVA-assisted spray deposited porous Li4Ti5O12 thin film as high-rate and long-cycle anode for lithium-ion thin-film batteries

Spinel Li4Ti5O12 (LTO), a zero-strain material, is a promising anode material for solid-state thin-film lithium-ion batteries (TFB). However, the preparation of high-performance Li4Ti5O12 thin-film electrodes through facile methods remains a significant challenge. Herein, we present a novel approach to prepare a binder- and conductor-free porous Li4Ti5O12 (P-LTO) thin-film. This approach polyvinyl alcohol (PVA)-assisted spray deposition and does not require the use of complex or expensive methods. Adding PVA to the precursor solution effectively prevents thin-film cracking during high-temperature annealing, enhances adhesion, and forms a highly interconnected porous structure. This unique structure shortens the lithium-ion diffusion pathways and facilitates electron transport. Therefore, P-LTO thin film electrodes demonstrate exceptional rate capacity of 104.1 mAh/g at a current density of 100C. In addition, the electrodes exhibit ultra-long cycle stability, retaining 80.9 % capacity after 10,000 cycles at 10C. This work offers a novel approach for the preparation of high-performance thin-film electrodes for TFBs.

A highly stable insertion type V1-xTixP solid solution as an anode material for high-rate lithium-ion batteries

As electric vehicles (EVs) grow in popularity, the demand for lithium-ion batteries (LIBs) simultaneously grows, and the fast-charging capability is becoming increasingly important. However, it is generally believed that graphite anode still suffers from a poor rate capability for fast-charging applications, and other insertion-type oxide anodes with a high rate capability exhibit too high Li+-ion insertion/extraction potential, which cannot meet a requirement for high energy density anodes. In this work, the hexagonal structure of V1-xTixP (x = 0.0, 0.25, and 1.0) phases were introduced as insertion-type anode materials for LIBs with a low reaction potential of Li+-ion insertion/extraction. The crystal structure and the corresponding electrochemical reaction mechanism of insertion-type anodes of TiP, VP, and MoP were compared. A facile strategy forming a substitutional solid solution is suggested to improve the electrochemical properties of anode materials by combining the end members among insertion-type VP, TiP, and MoP as forming V1-xTixP and V1-xMoxP compounds. V1-xTixP (x = 0.25) electrode, substituting V atoms with Ti atoms in VP structure, shows excellent long-term cycle stability at 1 A/g with a cycle retention of 87.7 % during 2500 cycles, delivering a two times higher capacity of 211.1 mAh g−1 compared to that of the commercial graphite electrode.

Effects of macrostructure of carbon support in preparation of C/Six/C anode materials for lithium-ion batteries via silane decomposition

Effects of macrostructure of carbon support in preparation of C/Six/C anode materials for lithium-ion batteries via silane decomposition

Synergistic effect of carbon nanotube and encapsulated carbon layer enabling high-performance SnS2-based anode for lithium storage

Tin disulfide (SnS2), due to large interlayer spacing and high theoretical capacity, is regarded as a prospective anode material for lithium-ion batteries. Nevertheless, the poor electron conductivity of SnS2 and huge volumetric change during the lithiation/delithiation process lead to a rapid capacity decay of the battery, hindering its commercialization. To address these issues, herein, SnS2 is in-situ grown on the surface of carbon nanotubes (CNT) and then encapsulated with a layer of porous amorphous carbon (CNT/SnS2@C) by simple solvothermal and further carbonization treatment. The synergistic effect of CNT and porous carbon layer not only enhances the electrical conductivity of SnS2 but also limits the huge volumetric change to avoid the pulverization and detachment of SnS2. Density functional theory calculations show that CNT/SnS2@C has high Li+ adsorption and lithium storage capacity achieving high reaction kinetics. Consequently, cells with the CNT/SnS2@C anode exhibit a high lithium storage capacity of 837 mAh/g after 100 cycles at 0.1 A/g and retaining a capacity of 529.8 mAh/g under 1.0 A/g after 1000 cycles. This study provides a fundamental understanding of the electrochemical processes and beneficial guidance to design high-performance SnS2-based anodes for LIBs.

Fabrication of NiO-CuO/RGO Composite for Lithium Storage Property

The lithium storage performance of binary transition metal oxide/graphene composites as anode materials has been attracting more interest from researchers, based on the fact that binary transition metal oxides and graphene are expected to create a synergistic effect and exhibit improved lithium storage characteristics. In this work, a NiO-CuO/reduced graphene oxide composite (NiO-CuO/RGO) was prepared by an ultrasonic agitation process. When the NiO-CuO/RGO is applied to the anode material for lithium-ion batteries (LIBs), the batteries display high discharge capacities (at 730 mA h/g after 100 cycles at 100 mA/g), high-rate performance (311 mA h/g with 5000 mA/g), and excellent stable cyclability (375 mA h/g within 2000 mA/g after 400 cycles). Such results indicate that the combination of NiO-CuO and RGO leads to enhanced lithium storage performance, for the RGO sheets inhibit the large volume change of binary NiO-CuO and enhance the fast transport of both lithium ions and electrons during the repeated lithium cycling processes.

Synergistic effect of LixSi/Li3N artificial interface and 3D framework for enabling Dendrite-free, long-life lithium metal anodes

Lithium metal is highly favored as an ideal anode material in future high-capacity lithium batteries due to its appealing properties. Nevertheless, the implementation of lithium metal batteries (LMBs) is severely plagued by challenges such as instable solid electrolyte interface (SEI), uncontrolled growth of dendrite, and severe volume expansion. Herein, to address the aforementioned issues, an artificial SEI layer is fabricated, which is comprised of LixSi alloy and Li3N. The in-situ generated LixSi/Li3N interface is formed on the carbon fiber (denoted as CF/LixSi/Li3N) through a spontaneous reaction between molten Li and Si3N4. Density functional theory (DFT) calculations reveal that LixSi alloy has low ion diffusion energy barrier, which facilitates the low nucleation overpotential of Li+ and enables homogeneous lithium deposition. Li3N can further promote the rapid Li+ transport due to the excellent Li+ conductivity. In addition, the reserved 3D space effectively mitigates the volume change along cycling procedure. Owing to the synergistic effect of the LixSi/Li3N protective layer and the 3D structure, the composite anode shows higher cycling stability with a lifetime of more than 3000 cycles at 1 mA cm−2. Furthermore, matched with commercial LiFePO4 (LFP) and LiNi5Co2Mn3O2 (NCM523) cathodes, the full cells also exhibit impressive electrochemical properties. This work introduces an ingenious approach for constructing stable lithium metal anodes and effective lithium metal batteries.

Lithium-Ion battery silicon Anodes: Surface engineering with novel additives for enhanced ion and electron transport

Silicon (Si) stands as a promising candidate for high-capacity anode materials in the next-generation lithium-ion batteries (LIBs) due to extremely high specific capacity. However, silicon application is hindered by its inherently poor electron and ion conductivities, as well as structural instability during the repeated charging/discharging. To address these challenges, a novel functional surface modification agent, diethylenetriaminepenta(methylenephosphonic) acid (DTPMP), was decorated on the surface of silicon particles for the first time. The experimental results demonstrate that the DTPMP effectively enhances the cohesion between nano Si particles. This study combines experimental observations with theoretical calculations to analyze the nucleophilic and electrophilic sites of DTPMP and carboxymethyl cellulose (CMC), elucidating the existence state of DTPMP on the nano Si surface. Furthermore, by examining the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), along with the electrostatic potential (ESP) of DTPMP and solvent molecules in conjunction with Li+, the impact of the phosphate group on the diffusion of Li+ and electrons at the nano Si surface was studied. The electron density difference (EDD) maps for DTPMP and CMC reveal that DTPMP exhibits a more pronounced response in the presence of an electric field, suggesting its enhanced role in facilitating Li+ diffusion. This research offers a novel perspective on enhancing the electrochemical performance of nano Si surfaces, paving the way for the development of advanced LIBs with improved energy storage capabilities.

A Strategy for Anode Recovery and Upgrading by In Situ Growth of Iron-Based Oxides on Microwave-Puffed Graphite.

Faced with the increasing volume of retired lithium-ion batteries (LIBs), recycling and reusing the spent graphite (SG) is of great significance for resource sustainability. Here, a facile method for transforming the SG into a carbon framework as well as loading Fe2O3 to form a composite anode with a sandwich structure is proposed. Taking advantage of the fact that the layer spacing of the spent graphite naturally expands, impurities and intercalants are eliminated through microwave thermal shock to produce microwave-puffed graphite (MPG) with a distinct three-dimensional structure. Based on the mechanism of microwave-induced gasification intercalation, a Fe2O3-MPG intercalation compound (Fe2O3-MPGIC) anode material was constructed by introducing iron precursors between the framework layers and subsequently converting them into Fe2O3 through annealing. The Fe2O3-MPGIC anode exhibits a high reversible capacity of 1000.6 mAh g-1 at 200 mA g-1 after 100 cycles and a good cycling stability of 504.4 mAh g-1 at 2000 mA g-1 after 500 cycles. This work can provide a reference for the feasible recycling of SG and development of high-performance anode materials for LIBs.

Multilayer Ti3C2Tx-loaded CoOHF composite structures for high-performance lithium-ion batteries

Research into new composites to enhance the performance of lithium-ion battery electrode materials has become a trendy area of study. Cobalt-based composites are particularly prominent due to their exceptional electrochemical performance and unique physicochemical properties. Additionally, Ti3C2Tx MXenes materials are anticipated to replace graphene and other carbonaceous materials since they possess an open structure and low lithium-ion diffusion barrier. In this work, we employed simple hydrothermal method to combine layered Ti3C2Tx with needle-shaped CoOHF. The resulting nanosheets showed an even dispersion of CoOHF in the surface, leading to a remarkable increase in specific capacity. Furthermore, Ti3C2Tx provided a higher number of lithium-ion active sites and improved the lithium-ion migration rate, while also ensuring the structure and stability of CoOHF. This composite material enables stable cycling for 1000 cycles at high current densities of 2 A g−1 and ultimately shows a large capacity of 802.4 mAh g−1 stably. Additionally, CoOHF/MXene composites display exceptional performance rate and cycling stability. This study highlights new feasible strategies for using multilayer Ti3C2Tx in lithium-ion batteries, along with metal hydroxyfluorides in new, highly efficient lithium-ion battery anode materials.

Influence of Polypyrrole on Phosphorus- and TiO2-Based Anode Nanomaterials for Li-Ion Batteries.

Phosphorus (P) and TiO2 have been extensively studied as anode materials for lithium-ion batteries (LIBs) due to their high specific capacities. However, P is limited by low electrical conductivity and significant volume changes during charge and discharge cycles, while TiO2 is hindered by low electrical conductivity and slow Li-ion diffusion. To address these issues, we synthesized organic-inorganic hybrid anode materials of P-polypyrrole (PPy) and TiO2-PPy, through in situ polymerization of pyrrole monomer in the presence of the nanoscale inorganic materials. These hybrid anode materials showed higher cycling stability and capacity compared to pure P and TiO2. The enhancements are attributed to the electrical conductivity and flexibility of PPy polymers, which improve the conductivity of the anode materials and effectively buffer volume changes to sustain structural integrity during the charge and discharge processes. Additionally, PPy can undergo polymerization to form multi-component composites for anode materials. In this study, we successfully synthesized a ternary composite anode material, P-TiO2-PPy, achieving a capacity of up to 1763 mAh/g over 1000 cycles.

Density functional theory study of doped coronene and circumcoronene as anode materials in lithium-ion batteries

Density functional theory calculations are carried out to investigate the adsorption properties of Li+ and Li on twenty-four adsorbents obtained by replacement of C atoms of coronene (C24H12) and circumcoronene (C54H18) by Si/N/BN/AlN units. The molecular electrostatic potential (MESP) analysis show that such replacements lead to an increase of the electron-rich environments in the molecules. Li+ is relatively strongly adsorbed on all adsorbents. The adsorption energy of Li+ (Eads-1) on all adsorbents is in the range of − 42.47 (B12H12N12) to − 66.26 kcal/mol (m-C22H12BN). Our results indicate a stronger interaction between Li+ and the nanoflakes as the deepest MESP minimum of the nanoflakes becomes more negative. A stronger interaction between Li+ and the nanoflakes pushes more electron density toward Li+. Li is weakly adsorbed on all adsorbents when compared to Li+. The adsorption energy of Li (Eads-2) on all adsorbents is in the range of − 3.07 (B27H18N27) to − 47.79 kcal/mol (C53H18Si). Assuming the nanoflakes to be an anode for the lithium-ion batteries, the cell voltage (Vcell) is predicted to be relatively high (> 1.54 V) for C24H12, C12H12Si12, B12H12N12, C27H18Si27, and B27H18N27. The Eads-1 data show only a small variation compared to Eads-2, and therefore, Eads-2 has a strong effect on the changes in Vcell.

Phosphorus-Doped Silicon for Li-ion Battery Applications: Studied with Electrochemical Isothermal Microcalorimetry, ATR-FTIR and XPS

Silicon (Si) has garnered significant attention as a potential anode material for lithium-ion batteries due to its high theoretical specific capacity. However, there are considerable challenges to address before practical implementation, primarily stemming from issues such as very large volume changes upon Li insertion/extraction, poor electrical conductivity, and an unstable solid-electrolyte interphase (SEI). We report here investigations on P-doped Si (SiPx) using electrochemical isothermal micro-calorimetry (EIMC), attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), and X-ray photoelectron spectroscopy (XPS) techniques. The EIMC measurements on SiPx revealed decreased parasitic reaction heat flows during the lithiation/de-lithiation cycles. The first cycle cell voltage profiles show decreased electrochemical reactivity for the SiPx. Analyses using ATR-FTIR and XPS on cycled electrodes suggest that the parasitic reaction products originate from solvent and electrolyte salt decomposition, with significantly lower amounts observed on the SiPx. Collectively, these findings endorse P-doping of Si as a promising strategy for Li-ion battery applications and demonstrate the unique advantages of performing EIMC measurements by focusing on the intrinsic losses from parasitic reactions, regardless of the electrode and cell configurations being optimized. In contrast, fully optimized configurations are necessary when using coulombic efficiency as the metric for cycle stability of the battery chemistry.

Robust silicon/carbon composite anode materials with high tap density and excellent cycling performance for lithium-ion batteries

Achieving high density while ensuring structural stability and low volume expansion during cycling remains challenging for Si-based anode materials in lithium-ion batteries (LIBs). Herein, we introduce a novel approach to address this issue by developing high tap-density carbon-coated sub-nano-Si-embedded activated carbon (ACSC) anode materials. The resulting ACSC exhibits an ultra-high true density exceeding 0.99 g cm−3 and a Si content of 48 % (abbreviated as ACS0.48C), leading to an impressive volumetric capacity of 2182 mA h cm−3. Despite the high tap density and Si content of ACS0.48C, the ACS0.48C/artificial graphite (ACS0.48C/AG) mixture demonstrates a remarkable capacity retention rate of 97.9 % after 200 cycles at 0.5 C, with a modest volume expansion rate of 7.3 % after 50 cycles. The outstanding electrochemical performance can be attributed to the structural stability of ACS0.48C throughout cycling. The AC scaffold provides a robust mechanical framework to prevent volume expansion and agglomeration of sub-nano-sized Si particles. Furthermore, the homogeneous mixing of amorphous Si and carbon at the atomic level ensures isotropic expansion, thereby enhancing structural stability. The unique structure of ACS0.48C, combining high tap density and superior cycling performance, offers a solution to the low tap density issue in nanostructures and introduces innovative concepts for the morphology and structural design of Si/C secondary particles.

Polyaniline-coated flower-like iron oxide served as anode material for superior-performance lithium-ion batteries

Transition metal oxides applied in anode for lithium-ion batteries are susceptible to particle aggregation during the cycling test, resulting in a low capacity retention during cycling process. In this study, Fe2O3/polyaniline microflowers were prepared via a simple liquid-phase oxidation and calcination process followed by polyaniline coating. Several characterization techniques demonstrated their morphology and chemical composition. When applied in anode for lithium-ion batteries, Fe2O3/polyaniline microflowers exhibit an ultrahigh specific capacity of 1847.1 mAh g−1 over 100 cycles at 0.1 A/g. A high specific capacity of 619.8 mAh g−1 was achieved after 300 cycles at 1.0 A/g. The high performance is mainly due to the polyaniline coating and flower-like microstructures, which can mitigate the volume change, improve the electrical conductivity and cycling stability, and contribute to the rapid Li+ diffusion. This work provides a new route for synthesizing advanced-performance Fe2O3-based anode material.

Insight into graphene/boron arsenide heterostructure used for high-performance lithium-ion battery anode materials: The first principles study

Two-dimensional (2D) van der Waals (vdW) heterostructures demonstrate potential applications in Lithium-ion batteries (LIBs) characterized by their elevated energy storage capacity and extended operational longevity as anode materials. The structures and electronic properties of graphene/boron arsenide (Gr/BAs) heterostructures, along with the adsorption and migration of lithium (Li) atoms within the structures, are methodically analyzed through first-principles studies underpinned by density functional theory. Our calculations indicate the metallic Gr/BAs heterostructures have the structural stability, where their mechanical strength is confirmed from the elastic constant. Its diffusion barrier of Li atoms (0.25 eV) is superior among similar anode materials. The Li atoms' diffusion coefficient within the Gr/BAs heterostructure at 300 K (1.27 × 10−10 m2/s) exceeds that observed in Gr (2.0×10−11 m2/s). Besides, the presence of Gr assists in maintaining the open-circuit voltage (OCV) of Gr/BAs heterostructures in the range of 0-1 V. The theoretical specific capacity of proposed heterostructure reaches 920 mAh/g. The present calculations suggest that the Gr/BAs heterostructure could serve effectively as an anode in LIBs due to its excellent electrical conductivity, small diffusion barriers and appropriate open-circuit voltage.