DSpace at VNU: Effect of Elasticity of the MoS2 Surface on Li Atom Bouncing and Migration: Mechanism from Ab Initio Molecular Dynamic Investigations

Subscriber access provided by University of Newcastle, Australia Article Effect of Elasticity of the MoS Surface on Li Atom Bouncing and Migration: Mechanism from Ab Initio Molecular Dynamic Investigations Thi Huynh Ho, Hieu Cao Dong, Yoshiyuki Kawazoe, and Hung Minh Le J Phys Chem C, Just Accepted Manuscript • DOI: 10.1021/acs.jpcc.6b09954 • Publication Date (Web): 19 Dec 2016 Downloaded from http://pubs.acs.org on December 24, 2016 Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication They are posted online prior to technical editing, formatting for publication and author proofing The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record They are accessible to all readers and citable by the Digital Object Identifier (DOI®) “Just Accepted” is an optional service offered to authors Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts The Journal of Physical Chemistry C is published by the American Chemical Society 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society Copyright © American Chemical Society However, no copyright claim is made to original U.S Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties Page of 41 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 The Journal of Physical Chemistry Effect of Elasticity of the MoS2 Surface on Li Atom Bouncing and Migration: Mechanism from Ab Initio Molecular Dynamic Investigations Thi H Ho1, Hieu C Dong1, Yoshiyuki Kawazoe2, Hung M Le3,4,* Faculty of Materials Science, University of Science, Vietnam National University, Ho Chi Minh City, Vietnam New Industry Creation Hatchery Center, Tohoku University, Sendai, 980-8579 Japan Computational Chemistry Research Group, Ton Duc Thang University, Ho Chi Minh City, Vietnam Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam ABSTRACT: Born-Oppenheimer molecular dynamics has been carried out to investigate the evolution of Li-atom trapping on the MoS2 surface A single Li atom is fired with initial kinetic energy level (0.2 eV or 2.0 eV) and various targeting factor x, which determines the collision angle After getting trapped, Li is observed to bounce elastically and glide on the MoS2 surface thanks to the "breathing" vibration of MoS2 Both firing energy and targeting factor x are shown to have a significant effect on the trapping and gliding processes It is found that higher value of targeting factor x (≥0.6) and initial firing energy (2.0 eV) would enhance Li migration on the MoS2 surface Also, analysis from electronic structure calculations of six representative Li-MoS2 ACS Paragon Plus Environment The Journal of Physical Chemistry 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page of 41 interacting configurations suggests that there is ionic interaction and partial charge transfer between the absorbed Li atom and MoS2 monolayer during the bouncing and migration process The HSE calculations for those structures unveils the metallization of MoS2 due to Li attachment ACS Paragon Plus Environment Page of 41 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 The Journal of Physical Chemistry I INTRODUCTION Over past few decades, transition metal sulfides have become an attractive material due to its considerable properties such as magnetism, superconductivity, fluorescence, and electrical properties.1-4 Among these compound, molybdenum disulfide (MoS2) has been also studied extensively for applications such as electrochemical energy storage and conversion material,5,6 catalyst,7-9 and solid lubricant.10,11 Recently, the demand for effective cathode materials of lithium-ion rechargeable batteries leads a great research interest concerning MoS2-Li interactions Like graphite, MoS2 has a hexagonal unit-cell structure and MoS2 nanoparticles can be classified as an inorganic nanocarbon analogue of structures like plate-like graphene,12 onionlike fullerenes,13 pipe-like nanotubes,14 which exhibits unique properties In MoS2, the atoms are covalently bonded to form a sandwich structure with two-dimensional S-Mo-S trilayers stacked together through weak Van der Waals interactions.15 With high theoretical specific capacity and good raw material abundance,16 MoS2 has been considered a suitable material for developing effective electrodes The weak interlayer interaction allows guest atoms and molecules to intercalate reversibly and diffuse through the weakly-bonding stacked layers.17,18 As a result, the intercalation process leads to two main effects: expansion of interlayer spacing and charge transfer from the guest to the MoS2 host.19 Because of such effects, MoS2 has been nominated as a reasonable choice for electrode materials Li et al.20 investigated the adsorption and diffusion of lithium atom on the MoS2, and the results showed that the Li mobility could be significantly facilitated in MoS2 nanosheets because Li binding energy decreases Rastogi et al.21 demonstrated that Li was one of the most effective adatoms to enhance the n-type mobile carrier density in MoS2 for battery applications In a previous study, structural transition between the thermodynamically unstable T ACS Paragon Plus Environment The Journal of Physical Chemistry 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page of 41 phase and the H phase was investigated with the involvement of adsorbing Li atoms Such a transition was shown to have a barrier, which might be reduced by increasing the concentration of Li atoms.22 By employing a first-principles calculations, Ersan et al.23 demonstrated a diffusion of Li on the MoS2(1-x)Se2x, and suggested that the adsorption of Li atoms might metallize the dichalcogenide layer Concerning the tendency of Li clustering on the MoS2 surface, Putungan and co-workers showed the case of two Li atoms sitting close to each other was energetically unfavorable because Li dimer would dissociate quickly and re-locate on nearest Mo top-sites.24 In such a study, the overall migration barrier for Li clustering was estimated as ~0.5 eV Although there have been several theoretical studies concerning the interaction between Li atom and single-layer MoS2 based on density functional theory, it is necessary to find out more about the interacting mechanism during a dynamic process Considering the fact that it still has limited data on molecular dynamics (MD) mechanism, we believe it is worthy to conduct a fundamental MD investigation to examine the behavior of Li atom on the MoS2 surface In this study, we employ direct ab initio molecular dynamic (MD) simulation of lithium atom collision with MoS2 at two different levels of Li-firing kinetic energy, i.e 0.2 eV and eV, while the MoS2 is set to thermally vibrate at room temperature (300 K) During the process, we investigate the role of elasticity of MoS2 in trapping Li atom, and find out how a Li atom interacts and diffuses on the MoS2 surface Subsequently, we choose several representative configurations to execute highly qualitative self-consistent calculations for studying the resultant modification on electronic structure properties We believe our theoretical study provides more physical insights and disambiguates the attaching process of Li atoms onto the MoS2 surface ACS Paragon Plus Environment Page of 41 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 The Journal of Physical Chemistry II METHODOLOGY In this study, our main objective is to investigate the progress of Li-atom trapping by the MoS2 surface when a single Li atom is allowed to move toward and collide with the semiconducting layer This objective can be attained by adopting a MD approach In our procedure, there are three primary steps: i Setting up a randomized configuration of the pure MoS2 surface (without Li) thermally vibrating at 300 K ii Executing ab initio MD for the Li-MoS2 system iii Selecting several interesting configurations from the trajectories to perform highly qualitative self-consistent calculations and study the electronic properties In the following sub-sections, we will describe in details how we set up a trajectory sample and what information should be extracted from the trajectory Setting up a randomized MoS2 configuration at 300 K In the initial stage, an MoS2 monolayer consisting of 27 atoms (9 Mo and 18 S atoms) in a (3×3) supercell is allowed to conduct thermal vibration at room temperature for a period of 500 Rydberg time units (Rtu), and a fixed step size of 0.5 Rtu is chosen for integrations In real time, such a period equals 24.19 fs For a (3×3) MoS2 supercell, the a lattice parameter for the twodimensional system is chosen as 9.59 Å, while 15 Å is assumed to be the length of the c lattice vector to guarantee the vacuum assumption for the Li atom in the system For simplicity of this case study, during the later MD investigation process, we make an assumption that the defined lattice parameters remain constant during the entire dynamic process of atoms ACS Paragon Plus Environment The Journal of Physical Chemistry 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page of 41 The Car-Parrinello MD25 (CPMD) technique implemented in the Quantum Espresso package26 is employed in this early stage The cut-off energy is chosen as 35 Rydberg and the Martin-Troullier norm-conserving pseudo-potentials27 are employed for the involving atoms (Mo, S, and Li) The MoS2 system is made experimentally realistic when the Mo and S atoms are allowed to fluctuate at 300 K After the CPMD process, the geometry and velocity configurations are stored in the database for later use A geometry configuration with well-randomized velocities is generated by simply choosing a configuration from this CPMD database Executing direct DFT molecular dynamics After constructing the data for thermally equilibrated configurations, we insert the Li atom into the system With the chosen size of unit cell, the distance between two adjacent Li atoms is 9.59 Å, which guarantees negligible interaction between Li atoms in the periodic system As a benchmark calculation, we perform a MD simulation with variable unit cell, in which the Li atom is migrating from one S-Mo-S potential trap to another, and learn that the unit cell parameter responses insignificantly during the Li migration process Therefore, all investigated cases herein are conducted with a fixed unit cell The Li atom is set the move toward MoS2 with two different levels of initial kinetic energy: 0.2 eV and eV Such energy levels are considered “low” because they will not cause a severe deformation to the MoS2 surface The higher energy level, eV, might be considered as a hard collision (bombardment) onto the surface The Li atom is located Å aside from the MoS2 surface, and its projection lies on top of a Mo atom We hereby consider 21 collision cases at each kinetic energy level In each case, the angle of striking velocity is varied as described below ACS Paragon Plus Environment Page of 41 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 The Journal of Physical Chemistry In the first case, the Li atom is set to strike perpendicularly to the MoS2 surface, and aim to an Mo atom (referred as D case) From cases to 11, Li is set to strike 10 different spots of destination on a projected Mo-S linkage (denoted as spot C in Figure 1) Let us denote R as the projected distance of an equilibrium Mo-S bond A spot of destination is located at the point x2R (Å) from the Mo atom as described in Figure 1, where x = 0.1, 0.2, …, 1.0 For convenience, we refer these cases as the C1, C2, , C10 cases From cases 12 to 21, Li is set to strike 10 different spots of destination resided on the bisecting vector of two Mo-S bonds (denoted as spot B in Figure 1) Again, those B spots of destination are appointed similarly to the previous cases with the x2R factor For convenience, we refer these as the B1, B2, , B10 cases In the trajectory integration process, we employ the velocity-Verlet method28 with a standard step size of 0.484 fs The atomic forces of Mo, S, and Li atoms are extracted directly from first-principles self-consistent calculations executed by the Vienna Ab Initio Simulation package.29-32 The well-established Perdew-Burke-Ernzerhof exchange-correlation functional33-35 is employed, while the kinetic-energy cut-off is chosen as 400 eV, which is a standard cut-off level and suitable for the cost of long-time Born-Oppenheimer MD simulations The projectoraugmented wave method36,37 is employed to construct the electronic wave-functions for the participant atoms, which describes the valence shells of 5s, 4d for Mo, 3s, 3p for O, and 2s, 2p for Li To save computational expense for the Born-Oppenheimer MD simulations, we only perform Γ-point calculations at each integration step A MD trajectory is terminated after 1,000 integration steps (10,000 Rtu) It should be noted that in the first step, we utilize the input structure produced by PBE calculations within the well-established Quantum Espresso package, which in principle should be produce analogous structural ground state with respect to the PBE calculations with VASP in the second step ACS Paragon Plus Environment The Journal of Physical Chemistry 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page of 41 Performing self-consistent calculations for the chosen Li-MoS2 complexes After finishing the MD process, we pay attention to several interacting configurations at the stage of Li movement toward the MoS2 surface, when there are interactions that may cause modifications to the band structure of MoS2 Therefore, qualitative spin-polarized self-consistent calculations with a k-point mesh of (12×12×1) are executed for the chosen structures To explore the partial density of states (PDOS), the Gaussian smearing technique is utilized with a spreading value of 0.01 eV, and the dipole correction is activated We perform Bader charger analysis38 to examine the amount of charge transfer between Li and MoS2 Moreover, the hybrid HSE calculations39 are also employed to investigate the electronic structures of the chosen configurations The cut-off energy level is chosen as 400 eV, while the k-point mesh of (3×3×1) is chosen for the HSE calculations III RESULTS AND DISCUSSION The collision of Li with MoS2 at the firing kinetic energy of 0.2 eV Initially, the initial kinetic energy of 0.2 eV is chosen because we would like to examine the slow absorption and diffusion processes In a previous study, Ersan et al.23 suggested that a single Li atom could find good settlement on the pure MoS2 surface with an adsorption energy of 1.92 eV as derived from first-principles calculations Figure and Figure shows the evolution of total kinetic energy terms of the MoS2 single-layer and Li during the BOMD processes for 21 investigated cases at 0.2 eV We observe that the MoS2 monolayer vibrates periodically at the average initialized temperature of 300 K, in which the S atoms tend to move up and down This seems more or less like a "breathing" behavior, and the vibrational period of MoS2 almost remains constant In the cases presented in this section, before Li collides ACS Paragon Plus Environment Page of 41 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 The Journal of Physical Chemistry with MoS2, the average periodic time for the thermal vibration is approximately 444.61 Rtu (21.51 fs) at 300 K However, even after Li successfully establishes bonding with MoS2, the vibrational period of the layer does not seem to be affected significantly In our MD process, MoS2 vibrates around its equilibrium position for about 2,200 Rtu (106.43 fs) while Li moves closer to MoS2 According to our kinetic energy examination (see Figure 2), at the average distance of 4.78 Å from the surface, Li seems to start getting attracted by the layer as the kinetic energy of Li increases dramatically The attracting effect becomes gradually intensive, and reaches the maximum level of attraction at the distance of 1.78 Å, where we conceive the largest momentum of Li moving toward MoS2 In more details, the kinetic energy magnitude of Li increases dramatically from 0.2 eV at the beginning to over eV thanks to the assistance of MoS2 breathing and strong attractions of MoS2 upon Li After that, the repulsive force begins to occur rapidly during the collision It is true that Li absorbs kinetic energy from MoS2 and there are effects of strong attractive and repulsive interactions MoS2 seems to vibrate stronger as proved by a significant increase of kinetic energy (more than 3.94 eV) at 4,200 Rtu (203.19 fs) This is due to the establishment of a stable bonding configuration between MoS2 and Li During the collision process, we also observe that Li can rebound several times However, the Li atom is quickly pulled back and joins the vibration with MoS2 It should be noted that the bouncing behavior does not provide enough momentum for Li to escape from the great attraction from the layer There are two circumstances that can occur then: i Li is trapped around the triangular region formulated by three S ions, or ii Li glides from a trap created by three nearest neighbor S atoms to the most nearby triangular trap We refer this behavior to as “migration” ACS Paragon Plus Environment Page 27 of 41 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 The Journal of Physical Chemistry (43) R, D.; Hehre, W.; Pople, J., Self-consistent Molecular-orbital Methods Extended Gaussian-type Basis for Molecular-orbital Studies of Organic Molecules J Chem Phys 1971, 54, 724 (44) Hay, P J.; Wadt, W R., Ab Initio Effective Core Potentials for Molecular Calculations Potentials for the Transition Metal Atoms Sc to Hg J Chem Phys 1985, 82, 270-283 ACS Paragon Plus Environment 27 The Journal of Physical Chemistry 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 28 of 41 Table The number of rebounds, required time for collision and gliding, and shooting angle for seven cases occurring the Li gliding The initial kinetic energy of Li is 0.2 eV Case The required time for Li to collide with MoS2 (fs) The number of rebounds The required time for Li gliding (fs) Shooting angle (o) C6 118.52 334.23 6.31 C7 121.45 321.73 8.57 C8 120.54 150.94 11.12 C9 123.87 136.90 13.99 C10 120.52 134.52 17.07 B7 119.01 333.85 8.57 B9 122.43 182.83 13.99 ACS Paragon Plus Environment 28 Page 29 of 41 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 The Journal of Physical Chemistry Table The number of rebounds, required time for Li to collide and glide, and shooting angle for 18 gliding cases with the initial kinetic energy of 2.0 eV Case The required time for Li to collide with MoS2 (fs) The number of rebounds The required time for Li gliding (fs) Shooting angle (o) D 59.98 343.52 0.00 C1 59.98 341.54 0.18 C2 59.98 338.21 0.70 C3 59.98 346.42 1.58 C4 59.98 356.47 2.81 C6 60.47 180.96 4.39 C7 61.44 78.99 8.56 C8 62.89 70.63 11.12 C9 67.25 71.64 13.97 C10 64.31 76.05 17.07 B1 59.98 342.06 0.18 B2 59.98 338.21 0.70 B3 59.98 333.82 1.58 B4 59.98 339.14 2.81 B6 60.47 209.06 4.39 B8 60.47 320.37 11.12 B9 61.44 55.122 13.97 B10 64.82 42.613 17.07 ACS Paragon Plus Environment 29 The Journal of Physical Chemistry 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 30 of 41 Table Calculated mean Bader charge for Mo, S and Li derived from PBE and HSE calculations, total magnetization, and Mulliken charge of Li of the six configurations of interest Mean Bader charge Mean Bader charge derived from PBE derived from HSE Total Mulliken calculation calculation magnetization charge of Li (proton charge) (proton charge) (µB/cell) (proton charge) Mo S Li Mo S Li (a) +1.00 -0.52 +0.37 +1.09 -0.56 +0.32 0.29 +0.99 (b) +1.01 -0.54 +0.72 +1.09 -0.58 +0.76 0.58 +0.97 (c) +0.99 -0.54 +0.86 +1.09 -0.59 +0.87 0.87 +1.12 (d) +1.03 -0.56 +0.77 +1.12 -0.60 +0.78 0.54 +0.02 (e) +1.01 -0.55 +0.84 +1.09 -0.59 +0.85 0.88 +1.15 (f) +1.04 -0.56 +0.82 +1.13 -0.61 +0.83 0.56 +1.04 ACS Paragon Plus Environment 30 Page 31 of 41 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 The Journal of Physical Chemistry Figure Top and side views of a computational experimental setup with the description for destination spots The green sphere represents the Li bullet ACS Paragon Plus Environment 31 The Journal of Physical Chemistry 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 32 of 41 Figure Kinetic energy terms of MoS2 (solid line) and Li (dashed line) for D case and C1-C10 cases at 0.2 eV ACS Paragon Plus Environment 32 Page 33 of 41 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 The Journal of Physical Chemistry Figure Kinetic energy terms of MoS2 (solid line) and Li (dashed line) for B1-B10 cases at 0.2 eV ACS Paragon Plus Environment 33 The Journal of Physical Chemistry 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 34 of 41 Figure (a) The x-, y-, and z-directional kinetic energies of Li versus the MD time, (b) The distances of Li to S atoms on the top layer and the approximated distance of Li to the surface during the MD process, (c) Several snapshots of Li on MoS2 in the C1 case at 0.2 eV ACS Paragon Plus Environment 34 Page 35 of 41 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 The Journal of Physical Chemistry Figure (a) The x-, y-, and z-directional kinetic energies of Li versus the MD time, (b) The distances of Li to S atoms on the top layer and the approximated distance of Li to the surface during the MD process, (c) Several snapshots of Li on MoS2 in the B7 case at 0.2 eV ACS Paragon Plus Environment 35 The Journal of Physical Chemistry 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 36 of 41 Figure The total kinetic energy of MoS2 (solid line) and Li (dashed line) for D case and C1C10 cases at eV ACS Paragon Plus Environment 36 Page 37 of 41 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 The Journal of Physical Chemistry Figure The total kinetic energy of MoS2 (solid line) and Li (dashed line) for B1-B10 cases at eV ACS Paragon Plus Environment 37 The Journal of Physical Chemistry 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 38 of 41 Figure (a) Kinetic energy of Li at the gliding moment, and (b) the elapsed time before gliding in all gliding cases at two different firing energy levels of 0.2 eV and eV ACS Paragon Plus Environment 38 Page 39 of 41 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 The Journal of Physical Chemistry Figure PDOS of MoS2 and Li for six chosen interacting configurations given by HSE calculations ACS Paragon Plus Environment 39 The Journal of Physical Chemistry 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Page 40 of 41 Figure 10 DOS of the pure MoS2 monolayer given by HSE calculations ACS Paragon Plus Environment 40 Page 41 of 41 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 The Journal of Physical Chemistry TOC Graphic ACS Paragon Plus Environment 41 ... Physical Chemistry Effect of Elasticity of the MoS2 Surface on Li Atom Bouncing and Migration: Mechanism from Ab Initio Molecular Dynamic Investigations Thi H Ho1, Hieu C Dong1, Yoshiyuki Kawazoe2,... materials Li et al.20 investigated the adsorption and diffusion of lithium atom on the MoS2, and the results showed that the Li mobility could be significantly facilitated in MoS2 nanosheets because Li. .. of Li atoms.22 By employing a first-principles calculations, Ersan et al.23 demonstrated a diffusion of Li on the MoS2( 1-x)Se2x, and suggested that the adsorption of Li atoms might metallize the