Surface/interfacial transport through pores control desalination mechanisms in 2D carbon-based membranes

The shortage of freshwater is a critical concern for contemporary society, and reverse osmosis desalination technology has gathered considerable attention as a potential solution to this problem. It has been recognized that the desalination process involving water flow through angstrom-sized pores has tremendous potential. However, it is challenging to obtain angstrom-sized pore structures with internal mass transfer and surface/interface properties matching the application conditions. Herein, a two-dimensional (2D) zeolite-like carbon structure (Carzeo-ANG) was constructed with unique angstrom-sized pores in the zeolite structure; then, the surface/interfacial transport behavior and percolation effect of the Carzeo-ANG desalination membrane were evaluated by density functional theory (DFT) calculations and classical molecular dynamics. The first-principles calculations in density functional theory were implemented through the Vienna ab initio simulation package (VASP), which is a commercial package for the simulation of carbon-based materials. The results show that Carzeo-ANG is periodically distributed with angstrom-sized pores (effective diameter = 5.4 Å) of dodecacyclic carbon rings, which ensure structural stability while maintaining sufficient mechanical strength. The remarkable salt-ion adsorption properties and mass transfer activity combined with the reasonable density distribution and free energy barrier for water molecules endow the membrane with superior desalination ability. At the pressure of 80 MPa, the rejection efficiency of Cl- and Na+ were 100% and 96.25%, and the membrane could achieve a water flux of 132.71 L cm-2 day-1 MPa-1. Moreover, the interconnected electronic structure of Carzeo-ANG imparts a self-cleaning effect.

Prospective utilization of boron nitride and beryllium oxide nanotubes for Na, Li, and K-ion batteries: a DFT-based analysis

CONTEXT

In the present work, we investigated the adsorption mechanism of natural sodium (Na), potassium (K), and lithium (Li) atoms and their respective ion on two nanostructures: boron-nitride nanotubes (BNNTs) and beryllium-oxide nanotubes (BeONTs). The main goal of this research is to calculate the gain voltage for Na, K, and Li ionic batteries. Density function theory (DFT) calculations indicated that the adsorption energy between Na + is higher than that of the other cations, and this is particularly clear in the BeONT. Furthermore, gain voltage calculations showed that BNNTs generate a higher potential than BeONTs, with the most significant difference observed in BNNT/Na + . This research provides theoretical insights into the potential uses of these nanostructures as anodes in Na, K, and Li-ion batteries.

METHOD

Density function theory used to compute the ground state properties for BeONT and BNNT with and without selected atoms and their ions (Li, K, and Na). B3LYP used for exchange correlation between electrons and ions, and 6-31G* basis set used for all atoms and ions. Gauss Sum 2.2 software used for estimate the density of state (DOS) for all structure under investigation.

On the Road to the Frontiers of Lithium-Ion Batteries: A Review and Outlook of Graphene Anodes

Graphene has long been recognized as a potential anode for next-generation lithium-ion batteries (LIBs). The past decade has witnessed the rapid advancement of graphene anodes, and considerable breakthroughs are achieved so far. In this review, the aim is to provide a research roadmap of graphene anodes toward practical LIBs. The Li storage mechanism of graphene is started with and then the approaches to improve its electrochemical performance are comprehensively summarized. First, morphologically engineered graphene anodes with porous, spheric, ribboned, defective and holey structures display improved capacity and rate performance owing to their highly accessible surface area, interconnected diffusion channels, and sufficient active sites. Surface-modified graphene anodes with less aggregation, fast electrons/ions transportation, and optimal solid electrolyte interphase are discussed, demonstrating the close connection between the surface structure and electrochemical activity of graphene. Second, graphene derivatives anodes prepared by heteroatom doping and covalent functionalization are outlined, which show great advantages in boosting the Li storage performances because of the additionally introduced defect/active sites for further Li accommodation. Furthermore, binder-free and free-standing graphene electrodes are presented, exhibiting great prospects for high-energy-density and flexible LIBs. Finally, the remaining challenges and future opportunities of practically available graphene anodes for advanced LIBs are highlighted.

Tuning the structural stability and electrochemical properties in graphene anode materials by B doping: a first-principles study

The first-principles method of density functional theory (DFT) is used to study the structural stability and electrochemical properties of B doped graphene with concentrations of 3.125%, 6.25% and 18.75% respectively, and their lithium storage mechanism and characteristics are further studied. The results show that the doped systems all have negative adsorption energy, indicating that the structures can exist stably, and the adsorption energy of lithium ions on graphene decreases with the increase of B doping concentration. Among them, the B₆C₂₆ structure has the lowest adsorption energy and can adsorb more lithium ions. The density of states indicates that doping with B can increase the conductivity of graphene greatly. Subsequently, the CI-NEB method to search for the transition state of the doped structure is used, showing that the B₆C₂₆ structure has the lowest diffusion barrier and good rate performance. Therefore, these findings provide a certain research foundation for the development and application of lithium-ion battery anode materials.

Fast Intercalation of Lithium in Semi-Metallic γ-GeSe Nanosheet: A New Group-IV Monochalcogenide for Lithium-Ion Battery Application

Existence of van der Waals gaps renders two-dimensional (2D) materials ideal passages of lithium for being used as anode materials. However, the requirement of good conductivity significantly limits the choice of 2D candidates. So far, only graphite is satisfying due to its relatively high conductivity. Recently, a new polymorph of layered germanium selenide (γ-GeSe) was proven to be semimetal in its bulk phase with a higher conductivity than graphite while its monolayer behaves semiconducting. In this work, by using first-principles calculations, the possibility was investigated of using this new group-IV monochalcogenide, γ-GeSe, as anode in Li-ion batteries (LIBs). The studies revealed that the Li atom would form an ionic adsorption with adjacent selenium atoms at the hollow site and exist in cationic state (lost 0.89 e to γ-GeSe). Results of climbing image-nudged elastic band showed the diffusion barrier of Li was 0.21 eV in the monolayer limit, which could activate a relatively fast diffusion even at room temperature on the γ-GeSe surface. The calculated theoretical average voltages ranged from 0.071 to 0.015 V at different stoichiometry of Li_x GeSe with minor volume variation, suggesting its potential application as anode of LIBs. The predicted moderate binding energy, a low open-circuit voltage (comparable to graphite), and a fast motion of Li suggested that γ-GeSe nanosheet could be chemically exfoliated via Li intercalation and is a promising candidate as the anode material for LIBs.

A First-Principles Study on the Multilayer Graphene Nanosheets Anode Performance for Boron-Ion Battery

Advanced battery materials are urgently desirable to meet the rapidly growing demand for portable electronics and power. The development of a high-energy-density anode is essential for the practical application of B³⁺ batteries as an alternative to Li-ion batteries. Herein, we have investigated the performance of B³⁺ on monolayer (MG), bilayer (BG), trilayer (TG), and tetralayer (TTG) graphene sheets using first-principles calculations. The findings reveal significant stabilization of the HOMO and the LUMO frontier orbitals of the graphene sheets upon adsorption of B³⁺ by shifting the energies from −5.085 and −2.242 eV in MG to −20.08 and −19.84 eV in 2B³⁺@TTG. Similarly, increasing the layers to tetralayer graphitic carbon B³⁺@TTG_asym and B³⁺@TTG_sym produced the most favorable and deeper van der Waals interactions. The cell voltages obtained were considerably enhanced, and B³⁺/B@TTG showed the highest cell voltage of 16.5 V. Our results suggest a novel avenue to engineer graphene anode performance by increasing the number of graphene layers.

Impact of Polypyrrole Functionalization on the Anodic Performance of Boron Nitride Nanosheets: Insights From First-Principles Calculations

Lithium-ion batteries (LIBs) have displayed superior performance compared to other types of rechargeable batteries. However, the depleting lithium mineral reserve might be the most discouraging setback for the LIBs technological advancements. Alternative materials are thus desirable to salvage these limitations. Herein, we have investigated using first-principles DFT simulations the role of polypyrrole, PP functionalization in improving the anodic performance of boron nitride nanosheet, BNNS-based lithium-ion batteries and extended the same to sodium, beryllium, and magnesium ion batteries. The HOMO-LUMO energy states were stabilized by the PP functional unit, resulting in a significantly reduced energy gap of the BNNS by 45%, improved electronic properties, and cell reaction kinetics. The cell voltage, ΔE_cell was predicted to improve upon functionalization with PP, especially for Li-ion (from 1.55 to 2.06 V) and Na-ion (from 1.03 to 1.37 V), the trend of which revealed the influence of the size and the charge on the metal ions in promoting the energy efficiency of the batteries. The present study provides an insight into the role of conducting polymers in improving the energy efficiency of metal-ion batteries and could pave the way for the effective design of highly efficient energy storage materials.

Exploring high-energy and mechanically robust anode materials based on doped graphene for lithium-ion batteries: a first-principles study

The adsorption of Li atoms on various types of doped graphene with substituents, including boron, nitrogen, sulfur and silicon atoms, has been theoretically investigated by first-principles calculations, based on the density functional theory.

Atomistic Dynamics Investigation of the Thermomechanical Properties and Li Diffusion Kinetics in ψ-Graphene for LIB Anode Material

A fundamental understanding of the thermomechanical properties of electrode materials and Li-ion diffusion kinetics is indispensable for designing high-performance Li-ion batteries (LIBs) with high structural stability and safety. Herein, we performed both molecular dynamics (MD) simulations and density functional theory (DFT) calculations to investigate the thermomechanical properties and Li diffusion kinetics in a two-dimensional (2D) defect-filled graphene-like membrane consisting of 5-, 6-, and 7-membered rings, called psi (ψ)-graphene. Our results reveal that ψ-graphene has a negative linear thermal expansion coefficient, a high specific heat capacity, and high elastic constants that satisfy the Born's criterion for mechanical stability, which can be elucidated as the evidence of strong anharmonicity in ψ-graphene because of the soft out-of-plane bending modes. These characteristics can help prevent the thermal runaway that can occur during overheating and prevent structural damage because of the severe volume expansion of the LIBs. In addition, the Li diffusion coefficient was estimated to be 10^-9 cm²/s at 300 K with a low Li migration activation energy (<0.16 eV), which suggests favorable electrode kinetics with fast Li conduction. Our DFT calculations also show that ψ-graphene can possess a fairly good theoretical capacity (339 mA h g^-1) and a lower Li diffusion barrier (<0.21 eV). Our results suggest that the new fundamental insights presented here will help to stimulate further experimental work on ψ-graphene for promising future applications as a superior electrode material for LIBs.

Determination of Dynamically Stable Electrenes toward Ultrafast Charging Battery Applications

Electrenes, an atomically thin form of layered electrides, are very recent members of the 2D materials family. In this work, we employed first-principle calculations to determine stable, exfoliatable, and application-promising 2D electrene materials among possible M₂X compounds, where M is a group II-A metal and X is a nonmetal element (C, N, P, As, and Sb). The promise of stable electrene compounds for battery applications is assessed via their exfoliation energy, adsorption properties, and migration energy barriers toward relevant Li, Na, K, and Ca atoms. Our calculations revealed five new stable electrene candidates in addition to previously known Ca₂N and Sr₂N. Among these seven dynamically stable electrenes, Ba₂As, Ba₂P, Ba₂Sb, Ca₂N, Sr₂N, and Sr₂P are found to be very promising for either K or Na ion batteries due to their extremely low migration energy barriers (5-16 meV), which roughly demonstrates 105 times higher mobility than graphene and two to four times higher mobility than other promising 2D materials such as MXene (Mo₂C).

Theoretical investigation of the use of nanocages with an adsorbed halogen atom as anode materials in metal-ion batteries

The applicability of C₄₄, B₂₂N₂₂, Ge₄₄, and Al₂₂P₂₂ nanocages, as well as variants of those nanocages with an adsorbed halogen atom, as high-performance anode materials in Li-ion, Na-ion, and K-ion batteries was investigated theoretically via density functional theory. The results obtained indicate that, among the nanocages with no adsorbed halogen atom, Al₂₂P₂₂ would be the best candidate for a novel anode material for use in metal-ion batteries. Calculations also suggest that K-ion batteries which utilize these nanocages as anode materials would give better performance and would yield higher cell voltages than the corresponding Li-ion and Na-ion batteries with nanocage-based anodes. Also, the results for the nanocages with an adsorbed halogen atom imply that employing them as anode materials would lead to higher cell voltages and better metal-ion battery performance than if the nanocages with no adsorbed halogen atom were to be used as anode materials instead. Results further implied that nanocages with an adsorbed F atom would give higher cell voltages and better battery performance than nanocages with an adsorbed Cl or Br atom. We were ultimately able to conclude that a K-ion battery that utilized Al₂₁P₂₂ with an adsorbed F atom as its anode material would afford the best metal-ion battery performance; we therefore propose this as a novel highly efficient metal-ion battery. Graphical abstract The results of a theoretical investigation indicated that Al₂₂P₂₂ is a better candidate for a high-performance anode material in metal-ion batteries than Ge₄₄ is. Calculations also showed that K-ion batteries with nanocage-based anodes would produce higher cell voltages and perform better than the equivalent Li-ion and Na-ion batteries with nanocage-based anodes, and that anodes based on nanocages with an adsorbed F atom would perform better than anodes based on nanocages with an adsorbed Cl or Br atom.

Shuttle inhibition by chemical adsorption of lithium polysulfides in B and N co-doped graphene for Li-S batteries

The advance of lithium sulfur batteries is now greatly restricted by the fast capacity fading induced by shuttle effect. Using first-principles calculations, various vacancies, N doping, and B,N co-doping in graphene sheets have been systematically explored for lithium polysufides entrapped in Li-S batteries. The LiS, LiC, LiN and SB bonds and Hirshfeld charges in the Li₂S₆ adsorbed defective graphene systems have been analyzed to understand the intrinsic mechanism of retaining lithium polysulfides in these systems. Total and local densities of states analyses elucidate the strongest adsorption sites among the N and B-N co-doped graphene systems. The overall electrochemical performance of Li-S batteries varies with the types of defects in graphene. Among the defective graphene systems, only the reconstructed pyrrole-like vacancy is effective for retaining lithium polysulfides. N doping induces a strong LiN interaction in the defective graphene systems, in which the pyrrolic N rather than the pyridinic N plays a dominant role in trapping of lithium polysulfides. The shuttle effect can be further depressed via pyrrolic B,N co-doped defective graphene materials, especially the G-B-N-hex system with extremely strong adsorption of lithium polysulfides (4-5 eV), and simultaneous contribution from the strong LiN and SB interactions.

First-principles study of dual-doped graphene: towards promising anode materials for Li/Na-ion batteries

The interaction of Li/Na with various DDG is studied with the help of DFT. Among them, the Be–B DDG systems exhibit exceptional properties, such as large storage capacities, excellent OCVs, good electronic conductivities, and minor changes in their planes. These properties show that Be–B DDG can serve as promising anode materials for LIBs/SIBs.

A DFT study on graphene, SiC, BN, and AlN nanosheets as anodes in Na-ion batteries

A great concern exists about the lifetime, cost, low-temperature performance, and safety of Li-ion batteries. Na-ion batteries (NIB) are an alternative to the Li-ion batteries due to the wide availability of sodium, its low cost, and nontoxicity. Here, we examined the Na and Na⁺ adsorption on nanosheets of carbon (graphene), AlN, BN, and SiC to explore their potential use as an anode in NIBs. The interaction of atomic Na was found to play the main role in producing different nanosheet cell voltages. Unlike the graphene and SiC nanosheets, the lone pairs on the surface of the AlN and BN nanosheets hinder the Na adsorption and significantly increase the cell voltage. The order of magnitude of the nanosheet cell voltage as an anode in NIBs is as follows: AlN (1.49 V) > BN (1.46 V) > > C (0.69 V) > SiC (0.61 V). The AlN and BN nanosheets may be appropriate compounds for NIBs and their cell voltages are comparable with carbon nanotubes.

ψ-Graphene: A New Metallic Allotrope of Planar Carbon with Potential Applications as Anode Materials for Lithium-Ion Batteries

Using state-of-the-art first-principles calculations, we propose a new two-dimensional (2D) carbon allotrope constructed by polymerizing the carbon skeletons of s-indacenes, named PSI (ψ)-graphene. We show that ψ-graphene has the lowest energy among all hitherto reported 2D allotropes of carbon composed of 5-6-7 carbon rings and is dynamically and thermally stable. This structure is metallic with robust metallicity against external strain. In addition, we find that the adsorption of Li atoms on ψ-graphene is exothermic, and the diffusion energy barrier is low and comparable to that of graphene. Furthermore, ψ-graphene can achieve a maximum Li storage capacity equivalent to that of LiC₆, suggesting its potential as an anode material for Li-ion batteries (LIBs). In addition, we show that increasing the number of hexagons in this structure can enhance the thermodynamic stability of the sheet while maintaining its metallicity. This study provides new insights into the design of new metallic carbon for nanostructured anode materials in the next generation of LIBs.

Theoretical investigation of properties of boron nitride nanocages and nanotubes as high-performance anode materials for lithium-ion batteries

In this paper, applications of B30N30, B36N36, BNNT(8, 0), and BNNT(10, 0) as anode materials for lithium-ion batteries were investigated by density functional theory (DFT) calculations. Results show that the average values of voltage cell (Vcell) and adsorption energy (Ead) of BNNT(8, 0) and BNNT(10, 0) were higher than B30N30 and B36N36 by approximately 0.405 V and 5.25 kcal/mol, respectively. The F functionalization of studied nanostructures as a strategy to improve the performance of these systems as anode materials of lithium-ion batteries was investigated. Results show that the F functionalization of studied nanostructures increases the average values of Vcell and Ead by approximately 0.182 V and 8.89 kcal/mol, respectively. Obtained results propose that F functionalized B36N36 and BNNT(10, 0) have larger Vcell and Ead values, and therefore, these nanostructures have a higher potential as anode materials for the lithium-ion battery.

Na-ion batteries based on the inorganic BN nanocluster anodes: DFT studies

It has been recently indicated that the Li-ion batteries may be replaced by Na-ion batteries because of their low safety, high cost, and low-temperature performance, and lack of the Li mineral reserves. Here, using density functional theory calculations, we studied the potential application of B₁₂N₁₂ nanoclusters as anode in Na-ion batteries. Our calculations indicate that the adsorption energy of Na⁺ and Na are about -23.4 and -1.4kcal/mol, respectively, and the pristine BN cage to improve suffers from a low cell voltage (∼0.92V) as an anode in Na-ion batteries. We presented a strategy to increase the cell voltage and performance of Na-ion batteries. We showed that encapsulation of different halides (X=F^-, Cl^-, or Br^-) into BN cage significantly increases the cell voltage. By increasing the atomic number of X, the Gibbs free energy change of cell becomes more negative and the cell voltage is increased up to 3.93V. The results are discussed based on the structural, energetic, frontier molecular orbital, charge transfer and electronic properties and compared with the performance of other nanostructured anodes.

The prospects of phosphorene as an anode material for high-performance lithium-ion batteries: a fundamental study

To completely understand lithium adsorption, diffusion, and capacity on the surface of phosphorene and, therefore, the prospects of phosphorene as an anode material for high-performance lithium-ion batteries (LIBs), we carried out density-functional-theory calculations and studied the lithium adsorption energy landscape, the lithium diffusion mobility, the lithium intercalation, and the lithium capacity of phosphorene. We also carried out, for the very first time, experimental measurement of the lithium capacity of phosphorene. Our calculations show that the lithium diffusion mobility along the zigzag direction in the valley of phosphorene was about 7 to 11 orders of magnitude faster than that along the other directions, indicating its ultrafast and anisotropic diffusivity. The lithium intercalation in phosphorene was studied by considering various Li _n P₁₆ configurations (n = 1-16) including single-side and double-side adsorptions. We found that phosphorene could accommodate up to a ratio of one Li per P atom (i.e. Li₁₆P₁₆). In particular, we found that, even at a high Li concentration (e.g. x = 1 in Li _x P), there was no lithium clustering, and the structure of phosphorene (when fractured) is reversible during lithium intercalation. The theoretical value of the lithium capacity for a monolayer phosphorene is predicted to be above 433 mAh g^-1, depending on whether Li atoms are adsorbed on the single side or the double side of phosphorene. Our experimental measurement of the lithium capacity for few-layer phosphorene networks shows a reversible stable value of ∼453 mAh g^-1 even after 50 cycles. Our results clearly show that phosphorene, compared to graphene and other two-dimensional materials, has great promise as a novel anode material for high-performance LIBs.

Monolayer BC2: an ultrahigh capacity anode material for Li ion batteries

Uniformly doped monolayered BC₂sheets show the highest ever reported specific capacity of 1667 mA h g⁻¹for B doped graphene sheets.

Modulating the electronic and magnetic properties of graphene

Graphene, an sp²hybridized single sheet of carbon atoms organized in a honeycomb lattice, is a zero band gap semiconductor or semimetal.

Engineering the Li Storage Properties of Graphene Anodes: Defect Evolution and Pore Structure Regulation

A general and mild strategy for fabricating defect-enriched graphene mesh (GM) and its application toward the anode of Li-ion batteries (LIBs) has been reported. The GM with a pore size of 60-200 nm is achieved by employing Fe₂O₃ as the etching reagent that is capable of locally etching the graphene basal plane in a relatively mild manner. Upon different drying technologies, that is, oven drying and freeze-drying, GMs with different porous structure are obtained. The electrochemical Li storage properties of GMs in comparison with graphene aerogels (GAs) disclose that both defect sites and porous structure are crucial for the final anodic performances. We show that only when merged with rich porosity, the GM anode can achieve a better Li storage performance than that of GA. Moreover, we further fabricated nitrogen-doped GM (NGM) using urea as the nitrogen source with a freeze-drying process. Benefiting from the unique structural characteristics, that is, plentiful defects, abundant pores, and nitrogen doping, the NGM anode exhibits high Li storage capacity with good cyclic stability (1078 mAh g^-1 even after 350 continuous cycles at a current density of 0.2 C) and outstanding rate capability. Our finding provides fundamental insights into the influence of defects and pore structure on the Li storage properties of graphene, which might be helpful for designing advanced graphene-based anodes for LIBs.

Enhanced Absorption and Diffusion Properties of Lithium on B,N,VC-decorated Graphene

Systematic first-principles calculations were performed to investigate the adsorption and diffusion of Li on different graphene layers with B/N-doping and/or C-vacancy, so as to understand why doping heteroatoms in graphene anode could significantly improve the performance of lithium-ion batteries. We found that the formation of single or double carbon vacancies in graphene are critical for the adsorption of Li atoms. While the N-doping facilitates the formation of vacancies, it introduces over binding issue and hinders the Li diffusion. The presence of B takes the excessive electrons from Li and N and reduces the energy barrier of Li diffusion on substrates. We perceive that these clear insights are crucial for the further development of graphene based anode materials for lithium-ion batteries.

Modelling of graphene functionalization

This perspective describes the available theoretical methods and models for simulating graphene functionalization based on quantum and classical mechanics.

Density functional theory study of Li binding to graphene

Using first-principle calculations, we studied the interaction between Li and graphene by considering the two kinds of models, which are related to the configurations of Li adsorption and the concentration of Li on graphene.

Graphene nanoplatelets with selectively functionalized edges as electrode material for electrochemical energy storage

In recent years, graphene-based materials have been in the forefront as electrode material for electrochemical energy generation and storage. Despite this prevalent interest, synthesis procedures have not attained three important efficiency requirements, that is, cost, energy, and eco-friendliness. In this regard, in the present work, graphene nanoplatelets with selectively functionalized edges (XGnPs) are prepared through a simple, eco-friendly and efficient method, which involves ball milling of graphite in the presence of hydrogen (H2), bromine (Br2), and iodine (I2). The resultant HGnP, BrGnP, and IGnP reveal significant exfoliation of graphite layers, as evidenced by high BET surface area of 414, 595, and 772 m(2) g(-1), respectively, in addition to incorporation of H, Br, and I along with other oxygen-containing functional groups at the graphitic edges. The BrGnP and IGnP are also found to contain 4.12 and 2.20 at % of Br and I, respectively in the graphene framework. When tested as supercapacitor electrode, all XGnPs show excellent electrochemical performance in terms of specific capacitance and durability at high current density and long-term operation. Among XGnPs, IGnP delivers superior performance of 172 F g(-1) at 1 A g(-1) compared with 150 F g(-1) for BrGnP and 75 F g(-1) for HGnP because the large surface area and high surface functionality in the IGnP give rise to the outstanding capacitive performance. Moreover, all XGnPs show excellent retention of capacitance at high current density of 10 A g(-1) and for long-term operation up to 1000 charge-discharge cycles.

Computational chemistry for graphene-based energy applications: progress and challenges

Research in graphene-based energy materials is a rapidly growing area. Many graphene-based energy applications involve interfacial processes. To enable advances in the design of these energy materials, such that their operation, economy, efficiency and durability is at least comparable with fossil-fuel based alternatives, connections between the molecular-scale structure and function of these interfaces are needed. While it is experimentally challenging to resolve this interfacial structure, molecular simulation and computational chemistry can help bridge these gaps. In this Review, we summarise recent progress in the application of computational chemistry to graphene-based materials for fuel cells, batteries, photovoltaics and supercapacitors. We also outline both the bright prospects and emerging challenges these techniques face for application to graphene-based energy materials in future.

N-substituted defective graphene sheets: promising electrode materials for Na-ion batteries

ViaDFT calculations, we theoretically demonstrated that the N doped defective structures are beneficial for Na adsorption and that the charge transfer can significantly influence the adsorption energies.