Intercalation Site Research Articles

Rational design of interlayer binding towards highly reversible anion intercalation cathode for dual ion batteries

Abstract Dual ion batteries are one of the emerging substitutes for lithium ion batteries with high operating voltages and energy density, but their recent advancements have been limited by unsatisfactory cathode stability in the form of irreversible exfoliation. To address this bottleneck, a strategy to selectively incorporate carboxylic anhydride functionality between graphite layers is developed to enforce a stabilizing effect to the crystal structure, which allows for effective performance optimization through particles downsizing and interlayer distance tuning without the compromises of intercalation site disruption and voltage deduction. The resulting graphite cathode experienced significant capacity, rate capability and stability improvements, achieving a highly reversible capacity of 91.2 mAh g−1 at 2 C, which then cycled consistently for over 1,000 cycles. Overall, this work removes a major handicap that has limited the development of dual ion batteries and demonstrates a design pathway for high performance graphite intercalation cathode suitable for anion intercalation with both enhanced stability and discharge capacity.

A novel palladium(II) antitumor agent: Synthesis, characterization, DFT perspective, CT-DNA and BSA interaction studies via in-vitro and in-silico approaches

Since numerous people annually pass away due to cancer, research in this field is essential. Thus a newly made and water like palladium(II) complex of formula [Pd(phen)(acac)]NO3, where phen is 1,10-phenanthroline and acac is acetylacetonato ligand, has been synthesized by the reaction between [Pd(phen)(H2O)2](NO3)2 and sodium salt of acetylacetone in the molar ratio of 1:1. It has been structurally characterized via the methods such as conductivity measurement, elemental analysis and spectroscopic methods (FT-IR, UV–Vis and 1H NMR). The geometry optimization of this complex at the DFT level of theory reveals that Pd(II) atom is situated in a square-planar geometry. The complex has been screened for its antitumor activity against K562 cancer cells which demonstrated efficacious activity. The interaction of above palladium(II) complex with CT-DNA as a target molecule for antitumor agents and BSA as a transport protein was studies by a variety of techniques. The results of UV–Vis absorption and fluorescence emission indicated that the Pd(II) complex interacts with EB + CT-DNA through hydrophobic and with BSA by hydrogen bonding and van der Waals forces at very low concentrations. In these processes, the fluorescence quenching mechanism of both the macromolecules seems to be the combined dynamic and static. The interaction was further supported for CT-DNA by carrying out the gel electrophoresis and viscosity measurement and for BSA by the circular dichroism and Förster resonance energy transfer experiments. Furthermore, results of partition coefficient determination showed that the [Pd(phen)(acac)]NO3 complex is more lipophilic than that of cisplatin. Moreover, molecular docking simulation confirms the obtained results from experimental tests and reveals that the complex tends to be located at the intercalation site of DNA and Sudlow's site I of BSA.

Anisotropic optical properties of single Si2Te3 nanoplates

We report a combined experimental and computational study of the optical properties of individual silicon telluride (Si2Te3) nanoplates. The p-type semiconductor Si2Te3 has a unique layered crystal structure with hexagonal closed-packed Te sublattices and Si–Si dimers occupying octahedral intercalation sites. The orientation of the silicon dimers leads to unique optical and electronic properties. Two-dimensional Si2Te3 nanoplates with thicknesses of hundreds of nanometers and lateral sizes of tens of micrometers are synthesized by a chemical vapor deposition technique. At temperatures below 150 K, the Si2Te3 nanoplates exhibit a direct band structure with a band gap energy of 2.394 eV at 7 K and an estimated free exciton binding energy of 150 meV. Polarized reflection measurements at different temperatures show anisotropy in the absorption coefficient due to an anisotropic orientation of the silicon dimers, which is in excellent agreement with theoretical calculations of the dielectric functions. Polarized Raman measurements of single Si2Te3 nanoplates at different temperatures reveal various vibrational modes, which agree with density functional perturbation theory calculations. The unique structural and optical properties of nanostructured Si2Te3 hold great potential applications in optoelectronics and chemical sensing.

Highly Porous Free-Standing rGO/SnO2 Pseudocapacitive Cathodes for High-Rate and Long-Cycling Al-Ion Batteries

Establishing energy storage systems beyond conventional lithium ion batteries requires the development of novel types of electrode materials. Such materials should be capable of accommodating ion species other than Li+, and ideally, these ion species should be of multivalent nature, such as Al3+. Along this line, we introduce a highly porous aerogel cathode composed of reduced graphene oxide, which is loaded with nanostructured SnO2. This binder-free hybrid not only exhibits an outstanding mechanical performance, but also unites the pseudocapacity of the reduced graphene oxide and the electrochemical storage capacity of the SnO2 nanoplatelets. Moreover, the combination of both materials gives rise to additional intercalation sites at their interface, further contributing to the total capacity of up to 16 mAh cm−3 at a charging rate of 2 C. The high porosity (99.9%) of the hybrid and the synergy of its components yield a cathode material for high-rate (up to 20 C) aluminum ion batteries, which exhibit an excellent cycling stability over 10,000 tested cycles. The electrode design proposed here has a great potential to meet future energy and power density demands for advanced energy storage devices.

Lithium intercalation in MoS2 bilayers and implications for moiré flat bands

Intercalation of lithium atoms between layers of 2D materials can alter their atomic and electronic structure. We investigate effects of Li intercalation in twisted bilayers of the transition metal dichalcogenide MoS$_2$ through first-principles calculations, tight-binding parameterization based on the Wannier transformation, and analysis of moir\'e band structures through an effective continuum model. The energetic stability of different intercalation sites for Li between layers of MoS$_2$ are classified according to the local coordination type and the number of vertically aligned Mo atoms, suggesting that the Li atoms will cluster in certain regions of the moir\'e superlattice. The proximity of a Li atom has a dramatic influence on the interlayer interaction between sulfur atoms, deepening the moir\'e potential well and leading to better isolation of the flat bands in the energy spectrum. These results point to the usefulness for the use of chemical intercalation as a powerful means for controlling moir\'e flat-band physics in 2D semiconductors.

Synthesis of lithium manganese oxide nanocomposites using microwave‐assisted chemical precipitation technique and their performance evaluation in lithium‐ion batteries

AbstractLithium manganese oxide (LMO), carbon nanotubes (CNTs), and graphene nanoplatelets (GNPs) were used to develop nanocomposites using a microwave‐assisted chemical precipitation method and characterized using various techniques. The process provides better control over morphological features and proficient choice of cost‐effective precursors. This research aims to increase the active surface area and the number of lithium‐ion (Li+) intercalation sites using the CNTs and GNPs in LMO to improve its electrochemical performance. The structural analysis shows that the average crystallite size is 50 nm without using any capping agent during the synthesis process, which is smaller when compared to pristine LMO. The electrochemical studies demonstrate that the incorporation of carbon nanostructures (CNTs and GNPs) boosts the rate capabilities and cyclic performance of LMO. The LMO‐CNTs and LMO‐GNPs have an excellent rate capability of 124 and 127 mAhg−1 at 0.1C, sustained at 115.6 and 118.5 mAhg−1 at 10C, respectively. Cycling efficiency is also improved, with LMO‐CNTs and LMO‐GNPs having an initial capacity of 124 and 127 mAhg−1 decreasing to 112 and 114 mAhg−1, respectively, after 50 cycles. Compared to pure LMO, the increased electrochemical performance of LMO nanocomposites is due to the introduction of carbon nanostructures (CNTs and GNPs).

Crystal structure and distortion of superconducting CuxBi2Se3

The crystal structure of the candidate topological superconductor ${\mathrm{Cu}}_{x}{\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ was studied by single-crystal neutron diffraction using samples obtained by inserting the Cu dopant electrochemically. Neither structural refinements nor calculated scattering-density maps find a significant occupation of Cu at the intercalation site between the quintuple layers of ${\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$. Following Bragg reflection intensities as a function of temperature, there is no signature of a structural phase transition between 295 and 2 K. However, the analysis of large sets of Bragg reflections indicates a small structural distortion breaking the rotational axis due to small displacements of the Bi ions.

Microwave Fusion of the Composite LiMn1.6Ni0.4O4-LiFePO4 /C to Improve the Stability of Spinel Phase

Lithium-ion batteries are a promissory technology for energy storage devices in electric vehicles and renewable energy generation systems. Lithium nickel manganese oxides (LMNO, spinel structure) are promising cathode materials for lithium-ion batteries because of their high potential (4.7V vs. Li/Li+, 147 mAhg-1), moderate thermal stability and environmental friendliness. However, their chemical stability and electronic conductivity needs to be improved for practical applications. The microwave fusion of composite material LiMn1.6Ni0.4 (LMNO, spinel) coated with LiFePO4 /C (LFP, olivine structure) is studied in order improve the stability of active material without reducing the active sites for lithium intercalation. Synchrotron diffractions shows superior crystallographic order and no further impurities precipitation for the composite material heated at 10W (see Figure 1). Electrochemical characterizations shows high cycled stability for LMNO-2LFP/C heated at 10W (97% after 100th cycles) (see Figure 2). The composite materials heated at 100W presents lower discharge capacity due to the changes in the lattice parameters and impurities precipitation during microwave heating. Sincrotron diffraction after 60th cycle in composite material heated at 10W shows the same lattice parameters for spinel phase and the reductions of lattice parameters for olivine structure in “b” direction. Figure 1

Higher Voltage, Wider Voltage Plateau, Longer Cycle Life, and Faster Kinetics Via Thermally Modulated Interfaces between Ramsdellite and Pyrolusite MnO2 for Lithium-Ion Battery Cathodes

The cathode for Lithium-ion batteries is dominated by transition metal oxides that exist in numerous polymorphic structures. To emphasize generality and the underpinnings of thermodynamics in the stability, activity, and kinetics of lithiation, we utilize the nomenclature of the native structure and non-native structure for referring to different transition metal oxides polymorphic structures. The native structure is the thermodynamic ground state (bulk phase) structure and various non-native structures have different discrete translational symmetry in their sub-surface regions compared to the native structure. Typically, non-native structures have higher (i.e. less negative) bulk formation energy and more open structures than the native structure. Hence, non-native structures are expected to generate higher discharge potential and better lithium mobility as a positive electrode material. However, non-native structures may be limited in stability, which can be increased by scaffolding them with the native structure. To explore these hypotheses, we synthesize pure Ramsdellite MnO2 (r/NN1-MnO2) and thermally phase transform it gradually to Pyrolusite MnO2 (β/N-MnO2) and intimately interfaced (r/NN1-MnO2)/(β/N-MnO2) intergrowth structures are obtained. As the temperature increases, the ratio of r/NN1-MnO2 to β/N-MnO2 in the intergrowth structure decreases; so does the discharge potential and lithium mobility in the lithium-ion coin cell. In addition, the galvanostatic discharge profile shows a wider discharge plateau for intergrowth structures as compared to the pure native and non-native structure. We rationalize these trends in discharge potential using formation energies computed via density functional theory followed by a statistical averaging to account for the different types of lithium intercalation sites in the intergrowth structures. The wider discharge plateau in the intergrowth structure is rationalized with the presence of additional interfacial sites of higher stability than the site available in single phase native and non-native structure. The capacity retention is higher for the intergrowth structure, which is ~64% compared to ~42% and ~32% as obtained for pure native and non-native structures after 100 cycles at a rate of 0.1C. The improved capacity retention for intergrowth structure is due to higher structural stability and available free volume, where the presence of native structure acts as a scaffold to stabilize the non-native structure. The electrochemical impedance spectroscopy suggests that the larger percentage of non-native structure helps in better transport due to greater free volume present in r/NN1-MnO2 structure with wider 2×1 channel compared to the native structure with the narrow 1×1 channel. This study demonstrates how a systematic control of the relative percentage of each phase, without change in chemical composition, helps in designing cathodes with improved capacity and cycle life, thereby expanding the available material space.

Hydrangea-Like CuS with Irreversible Amorphization Transition for High-Performance Sodium-Ion Storage.

Metal sulfides have been intensively investigated for efficient sodium‐ion storage due to their high capacity. However, the mechanisms behind the reaction pathways and phase transformation are still unclear. Moreover, the effects of designed nanostructure on the electrochemical behaviors are rarely reported. Herein, a hydrangea‐like CuS microsphere is prepared via a facile synthetic method and displays significantly enhanced rate and cycle performance. Unlike the traditional intercalation and conversion reactions, an irreversible amorphization process is evidenced and elucidated with the help of in situ high‐resolution synchrotron radiation diffraction analyses, and transmission electron microscopy. The oriented (006) crystal plane growth of the primary CuS nanosheets provide more channels and adsorption sites for Na ions intercalation and the resultant low overpotential is beneficial for the amorphous Cu‐S cluster, which is consistent with the density functional theory calculation. This study can offer new insights into the correlation between the atomic‐scale phase transformation and macro‐scale nanostructure design and open a new principle for the electrode materials' design.

Enhanced Coloration Efficiency of Electrochromic Tungsten Oxide Nanorods by Site Selective Occupation of Sodium Ions.

Coloration efficiency is an important figure of merit in electrochromic windows. Though it is thought to be an intrinsic material property, we tune optical modulation by effective utilization of ion intercalation sites. Specifically, we enhance the coloration efficiency of m-WO2.72 nanocrystal films by selectively intercalating sodium ions into optically active hexagonal sites. To accurately measure coloration efficiencies, significant degradation during cycling is mitigated by introducing atomic-layer-deposited Al2O3 layers. Galvanostatic spectroscopic measurement shows that the site-selective intercalation of sodium ions in hexagonal tunnels enhances the coloration efficiency compared to a nonselective lithium ion-based electrolyte. Electrochemical rate analysis shows insertion of sodium ions to be capacitive-like, another indication of occupying hexagonal sites. Our results emphasize the importance of different site occupation on spectroelectrochemical properties, which can be used for designing materials and selecting electrolytes for enhanced electrochromic performance. In this context, we suggest sodium ion-based electrolytes hold unrealized potential for tungsten oxide electrochromic applications.

Platinum(II) Probes for Sensing Polyelectrolyte Lengths and Architectures.

Platinum(II) polypyridine complexes of a square-planar geometry have been used as spectroscopic reporters for quantification of various charged species through non-covalent metal-metal interactions. The characterization of molecular weights and architectures of polyelectrolytes represents a challenging task in polymer science. Here, we report the utilization of platinum(II) complex probes and non-covalent metal-metal interactions for sensing polyelectrolyte lengths and architectures. It is found that the platinum(II) probes can bind to linear polyelectrolytes via electrostatic attractions and give rise to significant spectroscopic changes associated with the formation of metal-metal interactions, and the extent of the spectroscopic changes is found to increase with the lengths of the linear polyelectrolytes. Besides, the platinum(II) probes have been found to co-assemble with the linear polyelectrolytes to form well-defined nanofibers, and the lengths of the linear polyelectrolytes can be directly estimated from the diameter of the nanofibers under transmission electron microscopy observation. Interestingly, upon mixing with the platinum(II) probes, polyelectrolytes with bottlebrush architectures have been found to exhibit larger spectroscopic changes than linear polyelectrolytes with the same chemical composition. Combined with the reported theoretical studies on counterion condensation of polyelectrolytes, the platinum(II) complexes are found to function as spectroscopic probes for sensing the charge densities of the polyelectrolytes with different lengths and diverse architectures. Moreover, platinum(II) probes pre-organized in nanostructured aggregates have been found to intercalate into double-stranded DNA, which are naturally occurring biological polyelectrolytes with helical architectures and intercalation sites, to give significant enhancement of spectroscopic changes when compared to the intercalation of monomeric platinum(II) probes into double-stranded DNA.

Molecular Dynamics Simulation Study of N-14 Side Chain Substituted Styelsamines Binding to DNA

N-14 side chain substituted marine styelsamines are synthesized ligands that have been evaluated for DNA binding and antitumor activity. Experimental data show that these ligands bind to DNA, but its binding position on DNA structure is unclear. In the present study, binding position and binding affinity of substituted styelsamines to DNA structure were studied using docking method, molecular dynamics (MD) simulation, and molecular mechanics generalized born surface area (MMGBSA) analysis. Initial docked complexes were created by inserting an intercalation site between DNA base pairs. MD simulations on all complexes were carried out for 15 ns. MMGBSA analysis was used for determination of the binding energy and entropy. Comparison of the predicted binding energies to experimental IC 50 values shows that the predicted binding energies increase with decreasing experimental IC 50 values. So, it was concluded that the initial docked structures are reliable. Moreover, MMGBSA analysis showed that van der Waals energy term is the major term in predicted binding energy.

Higher voltage, wider voltage plateau, longer cycle life, and faster kinetics via thermally modulated interfaces between Ramsdellite and Pyrolusite MnO2 for lithium-ion battery cathodes

Non-native structures have more open structure with less stable bulk formation energy compared to their native structure and hence, non-native structured cathodes are expected to generate higher discharge potential and better lithium mobility. However, non-native structures are limited in stability, which can be enhanced by scaffolding with native structure. We synthesize highly crystalline non-native Ramsdellite MnO2 (r/NN1–MnO2) and gradually thermal phase transform to native Pyrolusite MnO2 (β/N–MnO2), intimately interfaced (r/NN1–MnO2)/(β/N–MnO2) intergrowth intermediate structures are realized. As the temperature increases, the ratio of r/NN1–MnO2 to β/N–MnO2 in intergrowth structure decreases, so does the discharge potential and lithium mobility. The wider discharge plateau for intergrowth structures is rationalized using density functional simulations followed by statistical averaging to account for interfacial intercalation sites with greater stability. Improved capacity retention for intergrowth structure is due to the higher structural stability and available free volume, where the presence of native structure acts as a stabilizing element. Electrochemical impedance spectroscopy correlates faster transport in the intergrowth structure with higher percentage of non-native phase with wider 2 × 1 channel compared to native phase with narrow 1 × 1 channel. The insights generated from this study have broad implications for interface engineering in multicomponent electrodes such as Li-rich-NMC oxides.

Fe-Doped CoP Flower-Like Microstructure on Carbon Membrane as Integrated Electrode with Enhanced Sodium Ion Storage.

Poor cyclability and rate performance always impede the development of transition metal phosphide-based anode materials. Many strategies have been used to address the above problems, such as the designing of hierarchical structures, combination with carbon materials, and doping with other metal elements. Considering those strategies, a flower-like Fe-doped CoP material is designed. The synthesis consists of microsheets grown on a carbon membrane (CM, leaves as precursor) through a hydrothermal method and in situ phosphorization. The Fe doping and carbon membrane synergistically induce the formation of a flower-like hierarchical microstructure during the crystal-growing process. The unique hierarchical microstructure increases the contact area between electrode and electrolyte, and accommodates the volume expansion during cycling. The hierarchical Fe-doped CoP grown directly on the carbon membrane increases the active sites for intercalation of sodium species and further promotes the internal electron conduction in the Fe-doped CoP/CM electrode. Thereby, the Fe-doped CoP/CM as the anode electrode for sodium ion batteries exhibits a high specific capacity of 515 mA h g-1 at 100 mA g-1 after 100 cycles. Even if the current density rises to 500 mA g-1 , the specific capacity is still maintained at 324 mA h g-1 after 500 cycles, showing superior rate performances and cyclability.

Platelet-like CuS impregnated with twin crystal structures for high performance sodium-ion storage

A platelet-like CuS material with twin crystals is successfully constructed. The twin crystal structure inside the material provides more channels and reaction sites for Na ions intercalation and conversion.

Understanding the factors controlling the photo-oxidation of natural DNA by enantiomerically pure intercalating ruthenium polypyridyl complexes through TA/TRIR studies with polydeoxynucleotides and mixed sequence oligodeoxynucleotides.

Ruthenium polypyridyl complexes which can sensitise the photo-oxidation of nucleic acids and other biological molecules show potential for photo-therapeutic applications. In this article a combination of transient visible absorption (TrA) and time-resolved infra-red (TRIR) spectroscopy are used to compare the photo-oxidation of guanine by the enantiomers of [Ru(TAP)2(dppz)]2+ in both polymeric {poly(dG-dC), poly(dA-dT) and natural DNA} and small mixed-sequence duplex-forming oligodeoxynucleotides. The products of electron transfer are readily monitored by the appearance of a characteristic TRIR band centred at ca. 1700 cm−1 for the guanine radical cation and a band centered at ca. 515 nm in the TrA for the reduced ruthenium complex. It is found that efficient electron transfer requires that the complex be intercalated at a G-C base-pair containing site. Significantly, changes in the nucleobase vibrations of the TRIR spectra induced by the bound excited state before electron transfer takes place are used to identify preferred intercalation sites in mixed-sequence oligodeoxynucleotides and natural DNA. Interestingly, with natural DNA, while it is found that quenching is inefficient in the picosecond range, a slower electron transfer process occurs, which is not found with the mixed-sequence duplex-forming oligodeoxynucleotides studied.

Hierarchical porous arrays of mesoporous Co3O4 nanosheets grown on graphene skin for high-rate and high-capacity energy storage

The rate capability of an anode material is limited by slow Li-ion diffusion dynamics within the bulk, which leads to slow charging rates and low power densities in Li-ion batteries. To address this issue, we fabricated novel 3D hierarchical porous oxide arrays composed of mesoporous Co3O4 nanosheets grown on a thin layer of reduced graphene oxide “skin” as a stable buffering and conducting layer. The porous oxide-graphene hybrid anode shows the outstanding rate capability (∼1400 mAh g−1 at 2.0 A g−1) among all oxide anode materials, high cycling stability and high retention of 84.5% over 200 cycles. Besides, the anode material in sodium-ion batteries also delivers a high capacity of 757 mAh g−1 and a high retention of 89.7% over 400 cycles. The high electrochemical performances are mainly due to mesoporous Co3O4 nanosheets provide abundant accessible sites for electrolyte diffusion and intercalation of Li+/Na+ ions into the active phases while the graphene coating dramatically boosts the overall Li/Na storage performances of the Co3O4 nanosheets by enhancing the binding to and electrical contact with the current collector. Kinetic analysis reveals that the rational integration of battery-type and capacitor-type electrochemical energy storage in the same anode material (the distinct 3D hierarchical porous structure) enables to offer excellent rate capability. This novel graphene-metal oxide nanopore array could be applied in high-performance Li-ion and Na-ion batteries.

Theoretical explanation for the DNA cleavage by GO with cation: anti-cooperativity effect among the π⋯π, cation⋯π/σ and H-bonding interactions in cytosine⋯GO⋯Mn+ (Mn+ = Na+, Mg2+, Al3+)

In order to reveal the nature of DNA cleavage by inorganic intercalator GO (graphene oxide) with cation, the cooperativity effects among the π⋯π, cation⋯π/σ and H-bonding interactions were evaluated in the cytosine⋯GO⋯Mn+ (Mn+ = Na+, Mg2+, Al3+) model systems using the M06-2X, MP2 and ω B97X-D methods with the 6-311++G(2d,p) and 6-311++G(3df,3pd) basis sets. The Mn+⋯O (ether) and N–H⋯O interactions induce the formation of the π⋯π stacking between cytosine and GO, and the anti-cooperativity effect are dominant in controling of the aggregation process of cytosine, GO and Mn+, which was confirmed by the AIM (atoms-in-molecules) and RDG (reduced density gradient) analyses. Furthermore, the solvent effects of H2O weaken greatly the anti-cooperativity effects. Thus, a deduction on the DNA cleavage by GO⋯cation with the intercalation mode is put forward: due to the anti-cooperativity effect and solvent effect, the π⋯π stacking is weakened in the complexes with Na+ or broken in those with Mg2+ or Al3+. Then the GO⋯Mg2+ moiety is squeezed out from the intercalating sites, leading to an invalid cleavage of DNA, while Na+ or Al3+ is bound tightly to cytosine, with a notable DNA cleavage. This deduction was used to explain reasonably the previous experimental phenomena.

Assessment of 2H–SiC based intercalation compound for use as anode in lithium ion batteries

The improvement in electrode materials to upgrade lithium ion battery (LIB) is at heart of research related to energy devices. Herein, we report on the prospects of using 2H–SiC as an anode material in LIB on the basis of first principles based theoretical predictions. The energy profiling of high symmetry structural sites pointed out that the site TC related to tetrahedral configuration with carbon is favorable intercalation site in the host. The reaction of Li with stoichiometric as well as non-stoichiometric 2H–SiC are found endothermic which points to their unsuitability for lithiation process in LIBs. However, Li intercalation into the host in presence of Si monovacancy appeared an exothermic process which motivated us to study this system in detail. The Li atom after intercalation into the host is found ionized thereby donating its 2s electron to carbon atoms. The average value of the lithium insertion voltage and theoretical capacity are calculated as 1.87 V and 85 mA h/g respectively for the host simulated in the form of supercell LixSi15C16. The diffusion barrier faced by lithium atom while moving along crystalline a-axis is minimum (among all the paths considered here) when it follows a path that links hexagonal rings while passing carbon atoms. On the other hand, in case of motion along c-axis, similar results are found for minimum energy path that is along Tc site. The low diffusion barrier will facilitate the lithium ion to move quickly that points to fast charging capability of the battery.