Adsorption Of Li Atoms Research Articles

Li decorated graphdiyne nanosheets: A theoretical study for an electrode material for nonaqueous lithium batteries

In this work, Density Functional Theory (DFT) is used to study pristine and defective GDY. We investigate the effect of Li atom adsorption on the electronic and structural properties of this 2D material. In both cases, the Li atom is located at the corner of the triangular‐like pore (H1), but with a slight shift for the defective system. In the perfect system, the Li‐C bond distances range from 2.289 Å to 2.461 Å, while in the defective case, they range from 2.237 Å to 3.184 Å. In the perfect case, the GDY‐Li system becomes metallic and the Li 2s states are stabilized. Charge transfer to the surfaces occurs near the vicinity of the Li atom. The C vacancy generates new C=C bonds similar to double bonds, enhancing the interaction with Li through strong conjugation. After Li adsorption, the sum of bond order for all the C atoms increases in both structures, from 0.4% to 6%. The Li storage capacity without significant restructuring is six Li atoms. When the atom concentration increases, the OCV values for Li decrease from 0.93 V to 0.23 V. For defective GDY, the specific capacity is 788 mAhg‐1, which is slightly higher than for pristine case.

TPDH-Graphene as a New Anodic Material for Lithium Ion Battery: DFT-Based Investigations.

The potential of tetra-penta-deca-hexagonal graphene (TPDH-gr), a recently proposed 2D carbon allotrope as an anodic material in lithium ion batteries (LIBs), was investigated through density functional theory calculations. The results indicate that Li-atom adsorption is moderate (around 0.70 eV), allowing for easy desorption. Moreover, energy barriers (0.08-0.20 eV), diffusion coefficient (>6 × 10-6 cm2/s), and open circuit voltage (0.29 V) calculations show rapid Li atom diffusion on the TPDH-gr surface, stable intercalation of lithium atoms, and good performance during the charge and discharge cycles of the LIB. These findings, combined with the intrinsic metallic nature of TPDH-gr, indicate that this new 2D carbon allotrope is a promising candidate for use as an anodic LIB material.

Effect of biaxial tensile-compressive deformation on the optoelectronic properties of monolayers of MoTe2 with adsorbed alkali metals X (X = Li, Na, K, Rb, Cs): a first principles

Based on a first-principles approach, the effects of tensile-compression deformation on the structural stability, electronic structure, and optical properties of monolayers of MoTe2 adsorbed with alkali metal atoms X (X = Li, Na, K, Rb or Cs) were calculated. It was found that the structural stability of the MoTe2 monolayer after adsorption of Li atoms was the most stable, with the smallest adsorption and formation energies and the smallest adsorption height. The movement of the Fermi energy toward the conduction band makes the system an n-type semiconductor. Subsequently, the adsorbed Li-MoTe2 monolayers were selected for tensile-compressive deformation, and with the increase of tensile deformation, the band gap decreased to zero at 10% deformation and exhibited metallic properties. As compressive deformation grows, the band gap shifts from direct to indirect, and metallic characteristics emerge when deformation approaches −10%. The Te-s and Te-p orbital electrons near the Fermi energy level and Mo-d orbitals make the main contribution to the adsorbed alkali metal molybdenum ditelluride system. In terms of optical characteristics, the MoTe2 system after alkali metal adsorption deformation is blue-shifted/ red-shifted at the absorption/reflection peak. These discoveries may help to broaden the possible applications of MoTe2 in low-dimensional electron-emitting devices.

Li-decorated C48B12 and Li12C48B12-impregnated MOF-5 for hydrogen storage: A multi-scale simulation study

In this study, we employed density functional theory (DFT) to investigate the adsorption sites and quantities of Li atoms on the C48B12 surface. Additionally, we examined the hydrogen adsorption properties of the formed Li12C48B12 through ab initio molecular dynamics (AIMD) simulations. Our AIMD simulations confirmed the stability of adsorbed Li atoms on the C48B12 surface, computed adsorbed H2 quantities, and predicted gravimetric densities of H2 adsorption on Li12C48B12 at 77 K and 298 K. Grand Canonical Monte Carlo simulations explored the H2 gravimetric densities of pure MOF-5, C48B12-impregnated MOF-5, and Li12C48B12-impregnated MOF-5 at 77 K and 298 K within 100 bar. Li doping on the C48B12 surface did not significantly enhance the gravimetric densities of H2 in MOF-5 but enhanced the stability of H2 adsorption in MOF-5.

Iron-arsenide monolayers as an anode material for lithium-ion batteries: a first-principles study.

This theoretical investigation delves into the structural, electronic, and electrochemical properties of two hexagonal iron-arsenide monolayers, 1T-FeAs and 1H-FeAs, focusing on their potential as anode materials for lithium-ion batteries. Previous studies have highlighted the ferromagnetic nature of 1T-FeAs at room temperature. Our calculations reveal that both phases exhibit metallic behaviour with spin-polarized electronic band structures. Electrochemical studies show that the 1T-FeAs monolayer has better ionic conductivity for Li ions than the 1H-FeAs phase, attributed to a lower activation barrier of 0.38 eV. This characteristic suggests a faster charge/discharge rate. Both FeAs phases exhibit comparable theoretical capacities (374 mA h g-1), outperforming commercial graphite anodes. The average open-circuit voltage for maximum Li atom adsorption is 0.61 V for 1H-FeAs and 0.44 V for 1T-FeAs. The volume expansion over the maximum adsorption of Li atoms on both phases is also remarkably less than the commercially used anode material such as graphite. Furthermore, the adsorption of Li atoms onto 1H-FeAs induces a remarkable transition from ferromagnetism to anti-ferromagnetism, with minimal impact on the electronic band structure. In contrast, the original state of 1T-FeAs remains unaffected by Li adsorption. To summarize, both 1T-FeAs and 1H-FeAs monolayers have potential as promising anode materials for lithium-ion batteries, offering valuable insights into their electrochemical performance and phase transition behaviour upon Li adsorption.

Explore the feasibility of Janus 2H-VSeTe monolayer as anode material for Li ion battery

Two-dimensional (2D) materials as potential energy storage systems have received extensive attention due to their high energy density and rate performance. Here, the electronic properties and feasibility of Janus 2H-VSeTe monolayer as LIBs anode material are systematically investigated using the first-principles calculations. No imaginary frequency in the phonon spectrum and the absence of obvious deformation simulated by AIMD simulations at 300 K prove the dynamic and thermal stability of Janus 2H-VSeTe monolayer, respectively. The pure Janus 2H-VSeTe monolayer exhibits a small direct band gap semiconductor character. The Li atom adsorption can result in the increase of electronic states near Ef and a transform of metallic behavior, ensuring good conductivity for the Janus 2H-VSeTe monolayer. On the other hand, the adsorbed Li atoms are fully ionized to ensure the charge and discharge process by the Bader analysis. Through the climbing-image nudged elastic band method, two possible migration paths are considered on the Se and Te surfaces, respectively. The lowest potential barriers are 0.159 eV and 0.188 eV, respectively, which proves that there is a high ion migration rate during charge and discharge process. The OCV and multi-layer Li atoms adsorption suggest that the corresponding specific capacity is 416 mA h g−1 for the Janus 2H-VSeTe monolayer, which reveals that Janus 2H-VSeTe monolayer is one of the feasible candidates for LIBs anode materials.

First-principles study of Li adsorption and diffusion in naphyne

The Li adsorption and diffusion properties in naphyne are explored by first-principles calculations. The porous structure of naphyne facilitates the adsorption of Li atoms, and the adsorption performance of large pores is better than that of small pores. The average open circuit potential is 0.78 V and the maximum Li storage capacity of bulk naphyne is up to 620 mAh/g, much larger than the up limit of the popular graphite. Upon Li intercalation, the interlayer spacing dilatation of bulk naphyne is only 1.78 %, implying that naphyne would not undergo significant structural degradation during cycling. The average adsorption energy between Li and naphyne in LiC3.6 is −2.38 eV/Li, which is feasible to realize their free migration. The porous structure enables Li atoms to diffuse either parallel or perpendicular to the naphyne plane. About 0.41–0.70 eV barriers are needed to overcome for the three-dimensional Li diffusion. Compared to commercial graphite, the higher Li capacity, the smaller structural distortion, and the unique three-dimensional diffusion performance of Li atoms make naphyne a promising candidate as the anode material of LIB.

A density functional theory study on the assessment of α-CN and α-CP monolayers as anode material in Li-ion batteries

Density functional theory (DFT) calculations were employed to probe the feasibility of 2D α-CM (M = N, P) as an anode material for Li-ion batteries (LIBs). Our findings demonstrate the dynamical, mechanical and thermal stability of 2D α-CM. In particular, for the 2D α-CP adsorbed with Li atom, binding energy (EB) of −2.00 eV ensures favourable adsorption. In contrast to 2D α-CP, the EB of adsorbed Li atom over α-CN is lower than the cohesive energy of lithium metal, this eliminates the accessibility of 2D α-CN as an anode in LIBs. The Li atom adsorption changes the nature of the 2D α-CP from semiconducting to metallic, ensuring high electronic conductivity. Both partial density of states and Lo¨wdin charge analysis indicate substantial charge transfer from Li atom to 2D α-CP after adsorption. The multilayer adsorption on both sides of 2D α-CP yields Li5.0CP monolayer with remarkably high specific storage capacity (1108.91 mAhg−1). The obtained average open circuit voltage is suitable for extensive battery application. Diffusion barrier of 0.11 eV shows ultrahigh ionic mobility over the 2D α-CP and thus facilitates charging/discharging process. As a result, high specific storage capacity, lower diffusion barrier, negligible volume change and excellent electronic conductivity imply the promising utility of 2D α-CP as anodic material in LIBs.

Li3Bi/Li2O layer with uniform built-in electric field distribution for dendrite free lithium metal batteries

Lithium metal batteries have garnered significant attention as a promising energy storage technology, offering high energy density and potential applications across various industries. However, the formation of lithium dendrites during battery cycling poses a considerable challenge, leading to performance degradation and safety hazards. This study aims to address this issue by investigating the effectiveness of a protective layer on the lithium metal surface in inhibiting dendrite growth.The hypothesis is that continuous lithium consumption during battery cycling is a primary contributor to dendrite formation. To test this hypothesis, a protective layer of Li3Bi/Li2O was applied to the lithium foil through immersion in a BiN3O9 solution. Experimental techniques including kelvin probe force microscopy (KPFM) and density functional theory (DFT) calculations were employed to analyze the structural and electronic properties of the Li3Bi/Li2O layer.The findings demonstrate successful doping of Bi into the Li coating, forming Bi-Bi and Bi-O bonds. KPFM measurements reveal a higher work function of Li3Bi/Li2O, indicating its potential as an effective protective layer. DFT calculations further support this observation by revealing a greater adsorption energy of lithium on the Li3Bi/Li2O layer compared to the bulk material. Charge density analysis suggests that the adsorption of Li atoms onto the Li3Bi/Li2O layer induces a redistribution of charge, resulting in increased electron availability on the surface and preventing electrode–electrolyte contact.This study provides insights into the role of the Li3Bi/Li2O protective layer in inhibiting dendrite growth in lithium metal batteries. By mitigating dendrite formation, the protective layer holds promise for enhancing battery performance and longevity. These findings contribute to the development of strategies for improving the stability and reliability of lithium metal batteries, facilitating their wider adoption in energy storage applications.

Armchair silicon carbide nanoribbon for potential anode material in lithium-ion batteries (LIBs).

In this work, we have investigated the electrochemical characteristics of armchair silicon carbide nanoribbon (ASiCNR) for its potential deployment as 2D lithium-ion battery anode material. Density functional theory approach is used to calculate the adsorption energy, storage capacity, and open circuit voltage of ASiCNR for LIB. Adsorption of Li atoms introduces the new energy bands which cross the Fermi level; this results in semiconductor to metallic transition of ASiCNR. It indicates the strong interaction of Li atoms towards the ASiCNR. When adsorption of Li atoms increases one by one, the adsorption energy (E[Formula: see text]) per Li atoms increases gradually. When all favourable sites are adsorbed by Li atoms E[Formula: see text] reached its maximum value and it results in maximum storage capacity of 818 mAhg[Formula: see text] and open circuit voltage of 1.15 V. Diffusion barrier of Li atoms for the substrate is 0.42 eV. Our computational results suggest that ASiCNR can be used as an anode material for Li-ion batteries, and it provides the theoretical background for the future study on ASiCNR and other Li storage structures.

Superconducting and transport properties of biphenylene network monolayer with alkaline metal adatoms

To explore novel two-dimensional superconductors, the recently prepared biphenylene network (BPN) monolayer with alkaline metal adatoms was investigated theoretically. Our study suggests that the superconducting critical temperature (Tc) of BPN monolayer could be increased from 0.03 to 11.22 K by adsorption of Li atoms, which induces increased density of states at the Fermi Level, softened vibrations and electron pockets at the Fermi surface. The diffusion barrier of Li/Na adatoms is very low (<0.25 eV), and it tends to decrease for high coverage. Average conductance was proposed to quantitatively evaluate the intrinsic conductivity and electronic transport anisotropy of two-dimensional materials. The adsorption of alkaline metal atoms enhances the transport anisotropy more than twice, and the direction with better conductance derives from the connected delocalized multi-center π bonds. Our study suggests that adsorption of metal atoms is an effective way to functionalize BPN monolayers, which endows them potential applications in future superconducting and electronic devices. It also implies that carbon monolayer allotropes like BPN monolayer may provide good platforms for both fundamental research and device applications, which stimulates more explorations in various fields.

Effects of strain and Li adsorption on the electronic structure and optical properties of arsenene

AbstractThe effects of shear deformation on the electronic structure and optical properties of intrinsic arsenene and arsenene adsorbed Li are investigated using a first‐principles approach. Shear deformation can transform the band gap of intrinsic arsenene from indirect‐direct‐indirect. After the adsorption of Li atoms by arsenene, it transforms from semiconductor to metal with a very obvious hybridization between the 2s orbital of Li and the 4p orbital of As. With the increase of shear deformation, the charge transfer increases and has a good modulation of the absorption coefficient and reflectivity. The adsorption of multiple Li atoms makes the dielectric constant of arsenene more sensitive to low energy spectra and increases the imaginary part of the photoconductivity, which increases the refractive index and decreases the extinction coefficient to some extent.

Investigation on electrochemical performance of striped, β12 and χ3 Borophene as anode materials for lithium-ion batteries

By developing next-generation lithium-ion batteries (LIBS), demand for exploring novel anode materials with exclusive electrochemical features and ultra-high capacity is increasing. In the current research, first-principles theory, and density functional theory (DFT) calculations were conducted to extensively investigate and compare the capability of three different borophene nanolayers, including striped, β12, and χ3 borophene, as a novel candidate for anode electrode in LIBs. We first predicted the most preferential Li atom adsorption sites on the three borophene structures. The predicted average formation energies for striped, β12, and χ3 borophene were obtained 3.123, 3.184, and 3.216 eV, respectively. The positive value of formation energy exhibits the sufficient stability of the structures. Moreover, the negative adsorption energy proved that Li atom insertion on all borophene monolayers is thermodynamically favorable. In order to simulate the lithiation process, we gradually increased the concentration of Li atoms. We found that the fully lithiated striped, β12 and χ3 borophenes could provide ultra-high specific capacities of 1700, 1983, and 1859 mAh/g, respectively. Structural analysis proved that the surface area expansion rate of the striped borophene in a fully lithiated state was 1%, which was lower than those of β12 and χ3 borophene with 3.33% and 2.63%, respectively. The analyses of electronic properties confirmed that borophenes were inherently metallic and superior ion conductive agents, even after fully lithiated state. Ion diffusion was studied using Nudged elastic band method and the value of diffusion energy barrier ranged from 0.03 to 0.36 eV which was lower than other promising 2D anode materials. Furthermore, open-circuit voltage results demonstrated that the electronic potential of modeled borophenes was low enough to be in the acceptable range of under 1.2V. All these reports exhibited that borophene nanolayers with excellent specific capacity and superior conductivity were desired candidates for anode materials of next generation LIBs.

Two-Dimensional α-SiX (X = N, P) Monolayers as Efficient Anode Material for Li-Ion Batteries: A First-Principles Study

Density functional theory simulations were performed to investigate the structural, electronic, and electrochemical properties of the two-dimensional α-SiX (X = N, P) monolayers as anode material in Li-ion batteries (LIBs). Our result indicates that α-SiX monolayers have excellent mechanical, dynamical, and thermal stability. The obtained adsorption energy values suggest that the Li atom adsorption over α-SiX is a favorable process. According to the Löwdin charge transfer and partial density of states analysis, charge transfer takes place from Li atom to α-SiX monolayers. From the band structure plots, we observed that after the adsorption of a single Li atom, the α-SiX monolayers are converted into a metallic state from the semiconductor state and remain in the metallic state for the different adsorption concentrations of Li atoms, which is essential to facilitate the diffusion of stored electrons. The calculated specific storage capacity is 956.16 and 733.66 mA h g–1 for α-SiN and α-SiP monolayers, respectively, which is remarkably higher than that of the conventional anode materials (such as graphite and TiO2). Ab initio molecular dynamics simulations confirm the room-temperature stability of the α-SiX monolayers at the maximum loading of Li atoms. The lower diffusion energy barriers of 0.30 eV (for α-SiN monolayers) and 0.16 eV (for α-SiP monolayers) ensure good diffusivity of ions over monolayers. The calculated open-circuit voltage is also favorable for battery applications. The aforementioned findings suggest that the α-SiX monolayers could be beneficial and compelling host anode material for high-performance LIBs.

Optical properties of Li-patterned graphene via a self-assembling molecular network.

Adsorbed Li atoms on graphene can tune its electronic properties in favor of various applications. The tendency of Li atoms for clustering on a graphene surface remains challenging. Herein, adsorption of Li atoms on graphene through a self-assembling network is investigated and its stability is verified via molecular dynamic calculations. Among the various properties that Li-doped graphene can possess, we explore its optical properties by calculating its electron energy loss spectra (EELS). We demonstrate that the variation in the distribution of Li atoms on graphene results in different peaks in the EELS curves.

S-functionalized 2D V2B as a promising anode material for rechargeable lithium ion batteries.

The development of novel high specific capacity anode materials is urgently needed for rechargeable metal ion batteries. Herein, S-functionalized V2B as the electrode material for Li/Na/K ion batteries are comprehensively investigated using first-principles calculations. Specifically, V2BS2 was verified with good electrical conductivity via band structure and density of states calculations. Phonon dispersion and ab initio molecular dynamic simulations were performed and confirmed the dynamic and thermal stability of V2BS2. The use of V2BS2 with a high theoretical specific capacity of 606 mA h g-1 for lithium ion batteries (LIBs) due to the bilayer adsorption of Li atoms is encouraging, which is attributed to the double empty orbitals of the S atoms and small lattice mismatch (1.5%) between the Li layers and substrate. Furthermore, dendrite formation would be well prohibited and safety issues for battery operation would be ensured for V2BS2 as electrode materials because of the low open circuit voltage with 0.37 V. The high charge/discharge rate for LIBs is also achievable owing to the high mobility of adatoms on the surface of V2BS2. Our work not only finds use as a promising material for the field of energy storage, but also provides constructive design strategies for developing high performance anode materials for rechargeable metal ion batteries.

Density functional theory study on the electronic structure and optical properties of Li absorbed borophene

The effects of bend angle on the stability, electronic structure and optical properties of Li-absorbed borophene system are studied by using density functional theory based on the first principles. The structure of borophene did not change significantly after adsorption of a Li atom, and the planar structure of borophene was not destroyed. Bending deformation affects the stability of the adsorption system and reduces the binding energy of the adsorption system. The adsorption of Li atoms obviously changes the energy band structure of borophene, and more impurity levels appear in the conduction band. The 2s orbital of Li and the 3p orbital of B are obviously hybridised. A charge transfer occurs between Li atoms and borophene. As the deformation increases, the amount of charge transfer increases. The bending angle affects the size of the absorption peak and reflection peak of the adsorption system.

Effects of Li adsorption on the physical properties of CrBr3 and CrCl3: From monolayer to multilayer

Two-dimensional ferromagnetic materials have attracted much attention for their potential application in information technology. The ferromagnetic properties of ultrathin CrCl3 and CrBr3 are investigated based on first-principles calculations. We find that adsorption of Li atoms results in half-metallic properties of ultrathin CrCl3 and CrBr3 and enhances the ferromagnetism in which the enhancement is not affected by the number of layers and the concentration of the adsorbed Li atoms, and the calculated forming energy and the diffusion process indicate that all structures are achievable. The investigation of bilayer structures shows that the stacking mode can affect their ferromagnetic stability.

The Li ion transport behavior in the defect graphene composite Li3N SEI: a first-principle calculation

An artificial solid electrolyte interface (SEI) of a graphene composite lithium salt can inhibit the growth of dendrites by driving the lithium deposition behavior on the surface of the lithium metal anode. The first-principle method was used to calculate the graphene/lithium nitride SEI, including the structural form and stability of intrinsic (G-Li3N), single-vacancy defect (SVG-Li3N), and double-vacancy defect (DVG-Li3N) graphene heterostructure. The adsorption and migration behavior of lithium ions on the heterostructure surface and the interface were also calculated. This study showed that the modification of double-vacancy defect graphene improved the stability of the heterostructure, and the adhesion work of the composite SEI is the highest. The modification of defective graphene increases the adsorption energy of lithium atoms on the surface and interface of the heterostructure: the strongest adsorption of Li atoms on the single-vacancy defect region of the heterostructure, the opposition migration pathway of Li atoms on the surface and interface of the DVG-Li3N heterostructure, and the decrease diffusion energy of Li atoms on the surface and interface of the DVG-Li3N heterostructure. A composite layered SEI of graphene and Li3N was constructed to inhibit dendritic growth by adjusting the deposition behavior of lithium atoms.

First-principle study of electronic properties and quantum capacitance of lithium adsorption on pristine and vacancy-defected O-functionalized Ti2C MXene

The electronic structure, surface charge storage and quantum capacitance of lithium adsorption on pristine and vacancy-defected Ti2CO2 MXene are theoretically investigated by density functional theory. Negative adsorption energies (Eads) of pristine Ti2CO2 (PT) and C-vacancy Ti2CO2 (VT) monolayers adsorbed by Li atom indicate that the adsorption processes of Li atom on systems are exothermic and favorable to adsorption. The most stable configurations are confirmed for the Li-adsorbed PT and VT monolayers. Pristine Ti2CO2 (PT) monolayer is a semiconductor with the bandgap of 0.2035 eV, while C-vacancy Ti2CO2 (VT) monolayer has the metallic nature. The adsorption of Li atom on PT monolayer makes the system undergo the semiconductor-metal transition, while the adsorption of Li atom on VT monolayer doesn’t change the metal nature. The magnetism is observed for the system with Li atom directly adsorbed on top of hollow site (VT-LH), and the total magnetic moments is 0.18 μB. Charge density differences of the adsorption of Li atom on PT and VT monolayers are further explored. The introduction of C-vacancy improves the quantum capacitances of the Li-adsorbed systems at 0 V, and Li-adsorbed PT and VT monolayers have high quantum capacitance because of the large density of states near Fermi level, and are suitable for cathode material.