Anode Material For Lithium-ion Batteries Research Articles

Structural modulation of Nb2O5 for enhanced Lithium-ion battery Performance: Insights from density functional theory and electrochemical characterization

Lithium-ion batteries (LIBs), extensively utilized today, encounter challenges with anode materials, such as capacity degradation and shortened cycle life during prolonged cyclic charging and discharging. These issues significantly hinder further advancements and applications of LIBs. Among various innovative anode materials, niobium pentoxide (Nb2O5) has garnered considerable interest due to its high specific capacity and exceptional cycling stability. However, different crystal types of Nb2O5 have different structures and properties, so they need to be studied in depth to find better anode materials for LIBs. In this paper, pseudo-hexagonal (TT-Nb2O5), orthorhombic (T-Nb2O5), and monoclinic (H-Nb2O5) crystalline forms of Nb2O5 have been prepared by simple ball milling and calcination methods. We have calculated the structural model of the material based on the density flooding theory (DFT), and the results have demonstrated that the T-Nb2O5 has a large structural advantage, which is characterized by a very low diffusion energy barrier, a low internal resistance, and a higher conductivity. The electrochemical properties of the material were also analyzed, and T-Nb2O5 has excellent cycling stability and rate performance. After 200 cycles (at 0.1A/g), the specific capacity of T-Nb2O5 was maintained at 440.8mAh/g. 3000 cycles at high current (at 5A/g) maintained a specific capacity of 95mAh/g. T-Nb2O5 has great potential, which has already been proved. With the continuous pursuit and development of energy storage technology, we believe that the research of different crystalline types of Nb2O5 will provide us with more efficient and reliable energy storage solutions.

Role of the Microstructure in the Li-Storage Performance of Spinel-Structured High-Entropy (Mn,Fe,Co,Ni,Zn) Oxide Nanofibers

High-entropy oxides with spinel structure (SHEOs) are promising anode materials for next-generation lithium-ion batteries (LIBs). In this work, electrospun (Mn,Fe,Co,Ni,Zn) SHEO nanofibers produced under different conditions are evaluated as anode materials in LIBs and thoroughly characterised by a combination of analytical techniques. The variation of metal load (19.23 or 38.46 wt% relative to the polymer) in the precursor solution and of calcination conditions (700 °C/0.5 h, or 700 °C/2 h followed by 900 °C/2 h) affects the morphology, microstructure, crystalline phase, and surface composition of the pristine SHEO nanofibers and the resulting electrochemical performance, whereas mechanism of Li+ storage does not substantially change. Causes of long-term (≥650 cycles) capacity fading are elucidated via ex situ synchrotron X-ray absorption spectroscopy. The results evidence that the larger amounts of Fe, Co, and Ni cations irreversibly reduced to the metallic form during cycling are responsible for faster capacity fading in nanofibers calcined under milder conditions. The microstructure of the active material plays a key role. Nanofibers composed by larger and better-crystallized grains, where a stable solid/electrolyte interphase forms, exhibit superior long-term stability (453 mAh g−1 after 550 cycles at 0.5 A g−1) and rate-capability (210 mAh g−1 at 2 A g−1).

High Performance Ti3+ Self-Doped Li4Ti5O12 Anode Materials Synthesized by an Electrochemical Method in Molten Salt

A simple synthesis for the Ti3+-doped, small Li4Ti5O12 is favorable for its application as an anode material of lithium-ion batteries. This study presents a direct synthesis method of high-performance Li4Ti5O12 (LTO-Ti) with the Ti3+ self-doped and uniformly small in size. It is carried out by the redox of an electrochemical electrode pair of Ti and Fe2O3 at a constant potential in molten KCl-LiCl salt with Li2CO3. The synthesis mechanism and the effect of synthesis conditions on the formation and properties of LTO-Ti were investigated in detail. The LTO-Ti with an average size of approximately 400 nm is prepared by the ionic level synthesis method, and exhibits a superior specific capacity of 130.5 mAh·g−1 at 10 C current density, which is 73.6% of its average specific capacity at 1 C. Moreover, it also shows good cycling stability with a specific capacity of 127.2 mAh·g−1 after 1000 cycles at 5 C (capacity retention of 96.9%). This synthesis is secure and prospective.

MoSe2 monolayer as a two-dimensional anode material for lithium-ion batteries: A first-principles study

Nowadays, finding applicable electrode materials with high energy density and high cycle stability is highly desired in the field of lithium-ion batteries. MoSe2 monolayer has been experimentally synthesized and shows satisfactory metal anchoring capability, making it a potential candidate for energy storage devices. In this work, first-principles calculations are employed to investigate the potential of MoSe2 monolayers with different phases (1T, 1T′ and 1H) as anode materials. The results show that 1T′-MoSe2 monolayer has excellent thermal, dynamical and mechanical stability. In addition, 1T′-MoSe2 monolayer exhibits metallic property under Li adsorption, ensuring good electrical conductivity for efficient electron transport. The Li atom has a low diffusion barrier of 0.299 eV on 1T′-MoSe2 monolayer, which results in a good charge-discharge rate. 1T′-MoSe2 monolayer has a maximum Li storage capacity of 422 mA h/g and an open-circuit voltage of 0.21 V. Our work reveals the application of 1T′-MoSe2 monolayer as an anode material for lithium-ion batteries and promotes the design of energy storage materials based on two-dimensional transition metal dichalcogenides.

Computational prediction of two dimensional Mo4BC as promising anode material for lithium-ion batteries

The rising demand for high-capacity energy storage systems drives the hunt for cutting-edge lithium-ion batteries. Herein, calculations based on density functional theory have been performed to investigate the properties of two-dimensional (2D) Mo4BC monolayer as an anode material with high stability and storage capacity. Phonon dispersion and ab initio molecular dynamics (AIMD) simulations were performed to determine the dynamic and thermal stability, respectively. A low diffusion barrier of 0.12 eV supports the ultrahigh ionic mobility of Li ions and cycling capability for this material, which is essential for the fast charging/discharging process. In addition, the Li-ion adsorption on Mo4BC shows a high capacity of about 800 mAhg−1 with an average open circuit voltage (Vocv) of 0.03 V. Comprehensive overview of Mo4BC as high-capacity anode material with negligible low diffusion barrier and metallic character provides a significant contribution towards the advancement of energy storage systems such as lithium-ion batteries (LIBs). Our findings suggest Mo4BC as a promising anode material for high-performance LIBs, thus offering valuable insights for exploring innovative anode materials.

Improved electrochemical performance of Cu-Sn/nano-SiO2 composite anode materials for lithium-ion batteries fabricated by controlled electrodeposition

Cu-Sn/nano-SiO2 composite materials are fabricated through electrodeposition process coupled with precise thermal treatment, which employs hexadecyl trimethyl ammonium bromide to guarantee the even distribution of nano-SiO2 particles within the Cu-Sn alloy framework. The characterization results indicate that integrating nano-SiO2 into the Cu-Sn matrix effectively prevents active particles from detaching from the copper foil current collector. By adjusting the current density, the electrochemical performance of the Cu-Sn/nano-SiO2 composite electrode is significantly enhanced. Specifically, the initial charge and discharge specific capacities of the composite electrolyte are approximately 746.6 and 1470.8 mAh/g at 100 mA/g, respectively. Moreover, the cell can still maintain a discharge specific capacity of 358.6 mAh/g after 100 cycles. Furthermore, the cell demonstrates an improved lithium-ion diffusion coefficient of approximately 9.639 × 10–15 cm²/s and a lower transfer resistance of 54.65 Ω. Therefore, a direct approach of fabricating the Cu-Sn/nano-SiO2 composite electrode with enhanced electrochemical properties may provide valuable guidance for alloy anodes in the energy storage field.

TPO12-graphene: A new two-dimensional metallic carbon with 4–5 ring for Lithium ion battery

For many decades, the stability of two-dimensional carbon structures involving connected 4–5 ring remained speculative. Recently, some of the planar carbon structures with connected 4–5 ring have showcased possible stability. In this work we present a new 4–5 ring carbon structure, belonging to Pmmm space group, having additional octagonal and dodecagonal rings to fill the space. The stability of this structure has been ensured in terms of its dynamical, thermal and mechanical stability. The electronic structure indicates that it is a non-magnetic metallic material. Moreover, the Fermi surface points to distinct electron and hole pockets in the first Brillouin zone. The quantum capacitance of the material suggests its use as anode in asymmetric supercapacitors. Besides its low optical absorption in visible range, its potential as an anode material for lithium-ion batteries is worth exploring. The storage capacity results of 558 mAh/g for the new material may be encouraging for its application as a lithium-ion battery anode material.

Enhanced performance of Mo-doped TiNb2O7 anode material for lithium-ion batteries via KOH sub-molten salt synthesis

TiNb2O7 (TNO) as an electrode material for lithium-ion batteries (LIBs) has relatively high safety and high theoretical capacity, making it an excellent alternative to the graphite anode. Nevertheless, its practical application is limited by its sluggish ionic and electronic conductivity. To address this challenge, Mo-doped TiNb2O7 (Mo-TNO) is synthesized via a KOH sub-molten salt method followed by calcining process. In this method, the low-cost raw materials are co-dissolved and then coprecipitated to achieve homogeneous mixing and particle refinement, further ensuring the uniformity of calcined products. The doping of Mo6+ facilitates cation mixing and charge compensation, leading to reduced charge transfer resistance and enhanced electronic conductivity. The reversible specific capacity of Mo-TNO after 300 cycles is maintained at 148 mA h g−1 with a high capacity-retention of 80 % at 5C. Even at 30C, it still exhibits a better capacity of 100.2 mA h g−1, much higher than the pristine TNO (58.9 mA h g−1). Furthermore, the full battery employing Mo-TNO as an anode and commercial LiNi0.6Co0.2Mn0.2O2 (NCM) as a cathode exhibits superior electrochemical performances with promising application prospect. These findings underscore the significant potential of Mo-TNO as a high-rate and long-life anode material for LIBs.

Lithium insertion/extraction mechanism in Mg2Sn anode for lithium-ion batteries

Due to its high capacity and excellent voltage properties, the Mg2Sn intermetallic phase is considered a promising anode material for next-generation lithium-ion batteries. However, the rapid capacity loss with cycling presently limits the application of Mg2Sn-based anodes. In this work, the Mg2Sn intermetallic phase was synthesized via a conventional casting method, and mechanisms of lithium ions intercalation into Mg2Sn alloy anodes were systematically studied. Density functional theory (DFT) calculations and electrochemical analyses identified two pathways involving four electrochemical reactions for Li+ intercalation/extraction in the Mg2Sn phase. The first pathway involves the insertion reaction of lithium ions into the octahedral sites of the Mg2Sn face center cubic (FCC) matrix, whilst the second involves the substitution of Mg by Li ions (releasing Mg metal). Furthermore, ex-situ EIS analysis and DFT calculations verified that adjusting the cut-off voltage range could control the reaction pathways. Excessively high or low cut-off voltages adversely impact the stability of the Mg2Sn anode. At cut-off voltages between 0.1 and 1 V, Mg2Sn anodes show very good capacity retention (78 % after 50 cycles), benefiting from the minimized formation of metallic Mg and Sn phases.

Mangosteen-like heterogeneous core-shell structured Mn2O3/Fe2O3 as anode material for high-performance lithium-ion batteries

Transition metal oxides with high capacity are considered ideal materials for anodes in lithium-ion batteries. In this study, nanospheres are prepared as a precursor with MnOX coated Fe3O4 by solvothermal method, and the Mn2O3/Fe2O3 composite with the mangosteen-like heterogeneous core-shell structure is formed by annealing method. During charging and discharging, the volume expansion is effectively alleviated by a mangosteen-like hollow structure. The heterogeneous Mn2O3/Fe2O3 composite with core-shell structure exhibits excellent electrochemical properties and recall ability. In the 0.01–2.5 V range, the capacity is 1042 mA h g−1 at 0.1 A g−1 after 280 cycles and 912.8 mA h g−1 at 0.5 A g−1 after 1400 cycles. In the 0.01–3 V range, a capacity is 957.5 mA h g−1 at 1.0 A g−1 after 550 cycles.

The Lithium Storage Mechanism of Zero-Strain Anode Materials with Ultralong Cycle Lives.

At present, graphite is a widely used anode material in commercial lithium-ion batteries for its low cost, but the large volume expansion (about 10%) after fully lithiated makes the material prone to cracking and even surface stripping in the cycle. Therefore, the development of zero-strain anode materials (volume change <1%) is of great significance. LiAl5O8 is a zero-strain insertion anode material with a high theoretical specific capacity. However, the Li+ storage mechanism remains unclear, and the cycle life as well as fast-charging capability need to be greatly improved to meet the practical requirements. In this study, LiAl5O8 nanorods are prepared by utilizing aluminum ethoxide nanowires as a soft template and doped with the Zr element to further improve the Li+ diffusion coefficient and electronic conductivity, which in turn improves cycle and rate performances. The Zr-doped LiAl5O8 presents a high reversible capacity of 227.2 mAh g-1 after 20,000 cycles under 5 A g-1, which significantly outperforms the state-of-the-art anode materials. In addition, the Li+ storage mechanisms of LiAl5O8 and Zr-doped LiAl5O8 are clearly clarified with a variety of characterization techniques including nuclear magnetic resonance. This work greatly promotes the practical process of zero-strain insertion anode materials.

WITHDRAWN: Novel design of Sn4P3@NxC electrodes and their electrochemical properties

Tin phosphide (SnxPy) is recognized as one of the most promising anode materials for lithium-ion batteries due to its exceptionally high theoretical capacity. However, its application is hampered by significant volume expansion during charge-discharge cycles and inferior electrical conductivity. Proper structural design placs a pivotal role in addressing these challenges, paving the way for high-performance anode materials. This study introduces a nitrogen-doped carbon-coated Sn4P3 nanosphere with a core-shell structure, employing dopamine as the nitrogen source. This innovative approach, utilizing template removal and solid-phase phosphorization, results in both the core and shell acting as active materials, thereby enhancing the volumetric energy density of the electrode. The internal voids within the shell layer mitigate volume expansion during charge-discharge cycles, while the presence of the nitrogen-doped carbon layer maintains the material's stability throughout cycling and improves its electrical conductivity. Electrochemical performance tests confirm the outstanding energy storage capability of this material, with an initial Coulombic efficiency reaching up to 73.6 %. Furthermore, it maintains a stable capacity of 585 mAh g^-1 after 1200 cycles at a current density of 2 A g^-1. This research offers a design paradigm for the development of novel energy storage materials.

Fabrication of SiO@Graphite@C@Al2O3 as Anode Material for Lithium-Ion Batteries

Fabrication of SiO@Graphite@C@Al2O3 as Anode Material for Lithium-Ion Batteries

Ion-crosslink alginate emulsion droplets toward synthesis of porous carbon microspheres as anodes for lithium-ion batteries

Porous carbon microsphere (PCM) is an important anode material for lithium-ion batteries; however, the preparation of PCM at large scale is still complex, sometimes even needing sophisticated instruments. Herein, we developed a water-in-oil (W/O) phase-separation strategy to prepare PCM in terms of simple and low-cost manner. As-prepared PCM has a large surface area of 182 m2/g, and abundant mesopores, which benefits the penetration of Li+-carrying electrolyte into the electrode. Therefore, the optimized PCM electrode shows a high-rate capability (408 mA h g−1 at 2 A/g). This work broadens a new vision in preparing PCM for energy-storage/-conversion applications.

N-doped C encapsulated Li2TiSiO5 nanoparticles for high-rate highly stable lithium storage

Achieving high charging rates (≤ 15 min) in lithium-ion batteries (LIBs) is imperative for their widespread implementation in all-electric vehicles. However, the pursuit of elevated charging rates often leads to compromises in capacity and cycling stability. In this manuscript, we present a groundbreaking approach utilizing a composite material composed of nitrogen-doped carbon-encapsulated Li2TiSiO5 nanoparticles (LTSO@C-N) as the anode material for LIBs, offering rapid and exceptionally stable lithium storage. The encapsulation of Li2TiSiO5 nanoparticles by nitrogen-doped carbon is realized via a facile liquid-phase polymerization and the following pyrolysis route. The uniformly deposited nitrogen-doped carbon layer on the surface of Li2TiSiO5 nanoparticles within LTSO@C-N serves a dual purpose: enhancing the conductive properties of Li2TiSiO5 to ensure efficient charge transfer and Li+ transport, while concurrently inhibiting grain pulverization over extended cycling periods. The deliberate incorporation of nitrogen-doped carbon optimizes Li2TiSiO5 anode electrochemical performance, simultaneously reducing structural degradation during prolonged cycling. This enhances the lithium-ion battery system's long-term stability and reliability. While exhibiting an average operational potential of approximately 0.28 V in comparison to Li+/Li, the LTSO@C-N electrode manifests a commendable specific capacity of 345 mAh g-1 at a current density of 0.1 A g-1. Notably, it attains a robust lithium storage capability even under high-rate conditions, exemplified by a sustained capacity of 205 mAh g-1 over 1000 cycles at 2 A g-1, devoid of any discernible decay. The electrode's impressive electrochemical performance highlights its potential as an advanced anode for high-performance lithium-ion batteries, ensuring stability.

Core-Double-Shell TiO2@Fe3O4@C Microspheres with Enhanced Cycling Performance as Anode Materials for Lithium-Ion Batteries.

Due to the volume expansion effect during charge and discharge processes, the application of transition metal oxide anode materials in lithium-ion batteries is limited. Composite materials and carbon coating are often considered feasible improvement methods. In this study, three types of TiO2@Fe3O4@C microspheres with a core-double-shell structure, namely TFCS (TiO2@Fe3O4@C with 0.0119 g PVP), TFCM (TiO2@Fe3O4@C with 0.0238 g PVP), and TFCL (TiO2@Fe3O4@C with 0.0476 g PVP), were prepared using PVP (polyvinylpyrrolidone) as the carbon source through homogeneous precipitation and high-temperature carbonization methods. After 500 cycles at a current density of 2 C, the specific capacities of these three microspheres are all higher than that of TiO2@Fe2O3 with significantly improved cycling stability. Among them, TFCM exhibits the highest specific capacity of 328.3 mAh·g-1, which was attributed to the amorphous carbon layer effectively mitigating the capacity decay caused by the volume expansion of iron oxide during charge and discharge processes. Additionally, the carbon coating layer enhances the electrical conductivity of the TiO2@Fe3O4@C materials, thereby improving their rate performance. Within the range of 100 to 1600 mA·g-1, the capacity retention rates for TiO2@Fe2O3, TFCS, TFCM, and TFCL are 27.2%, 35.2%, 35.9%, and 36.9%, respectively. This study provides insights into the development of new lithium-ion battery anode materials based on Ti and Fe oxides with the abundance and environmental friendliness of iron, titanium, and carbon resources in TiO2@Fe3O4@C microsphere anode materials, making this strategy potentially applicable.

Lithium-Ion Dynamic and Storage of Atomically Precise Halogenated Nanographene Assemblies via Bottom-Up Chemical Synthesis.

Graphene has received much scientific attention as an electrode material for lithium-ion batteries because of its extraordinary physical and electrical properties. However, the lack of structural control and restacking issues have hindered its application as carbon-based anode materials for next generation lithium-ion batteries. To improve its performance, several modification approaches such as edge-functionalization and electron-donating/withdrawing substitution have been considered as promising strategies. In addition, group 7A elements have been recognized as critical elements due to their electronegativity and electron-withdrawing character, which are able to further improve the electronic and structural properties of materials. Herein, we elucidated the chemistry of nanographenes with edge-substituted group 7A elements as lithium-ion battery anodes. The halogenated nanographenes were synthesized via bottom-up organic synthesis to ensure the structural control. Our study reveals that the presence of halogens on the edge of nanographenes not only tunes the structural and electronic properties but also impacts the material stability, reactivity, and Li+ storage capability. Further systematic spectroscopic studies indicate that the charge polarization caused by halogen atoms could regulate the Li+ transport, charge transfer energy, and charge storage behavior in nanographenes. Overall, this study provides a new molecular design for nanographene anodes aiming for next-generation lithium-ion batteries.

Self-consuming expansion stress construct piezoelectric field to accelerate anion for SiO/PbZr0.52Ti0.48O3 with persistent lithium storage performance

The high theoretical specific capacity and suitable working potential of silicon oxides (SiOx) making it one of the most promising candidates for the next generation of lithium-ion battery anode materials. However, the large-scale application of SiOx in lithium-ion battery anodes is hampered by the huge volume change (>200 %) during cycling process. This experiment adopts a method which is completely contrary to the traditional modification method——composite with piezoelectric materials to take advantage of this expansion. During the lithiation process, the significant volume expansion stress of SiO is transformed into a driving force by PbZr0.52Ti0.48O3 (PZT) particles that enhances the transport of Li+. The polarization of PZT particles occurs as a result of the consumption of mechanical stress caused by the expansion of SiO, leading to the generation of a piezoelectric potential. Since then, the volume expansion stress of SiO when deintercalating lithium is converted into a potential difference, which can promote the migration of Li+. This process not only reduces the volume expansion of SiO, but also promotes the mobility of Li+. The SiO/PZT anode shows an admirable cycle performance: The discharge capacity is 825.4 mA h g−1, and the capacity retention ratio is reach up to 92.5 % (200 mA g−1, 200 cycles). These findings illuminate the surface coupling approach employed to regulate the behavior of interfacial Li+ kinetics, while simultaneously enhancing the structural stability of alloy-based anodes. This research will undoubtedly capture the attention of researchers engaged in the study of multifunctional interface design for electrochemical systems.

Antimony Trisulfide with Graphene Oxide Coated Titania Nanotube Arrays as Anode Material for Lithium-ion Batteries

Antimony Trisulfide with Graphene Oxide Coated Titania Nanotube Arrays as Anode Material for Lithium-ion Batteries

β12-Borophene/Graphene Heterostructure as a High-Performance Anode Material for Li-Ion Batteries.

In the world of two-dimensional (2D) materials, various Borophene allotropes have gained significant attention for their remarkable specific capacity. However, the instability of monolayers has challenged experimental investigations of innovative approaches. Due to this limitation, in this work, graphene was investigated as a sublayer with the aim of providing stability to the β12-borophene monolayer. This study delves into the potential of a novel β12-borophene/graphene (β12-B/G) van der Waals (vdW) heterostructure using Quantum Espresso software based on vdW-corrected density functional theory. Our investigation includes exploring thermal and dynamical stability, adsorption energy, open circuit voltage, specific capacity, and diffusion barrier energy properties. Impressively, the calculated specific capacity reached 907 mAh/g, outperforming other 2D materials and heterostructures. The combination of a graphene layer not only ensures dynamical stability but also provides the adsorption energy of lithiumon the β12-borophene layer, simultaneously decreasing the diffusion barrier energy in comparison with the β12-borophene monolayer. The calculated open circuit voltage falls in the range 0.08-1.09 V, rendering it suitable for an overall average commercial voltage. For the borophene layer, the computed diffusion barrier energies are approximately 0.52 and 0.78 eV. Collectively, these findings underscore the potential of theβ12-B/G heterostructure as an advanced anode material for lithium-ion batteries.