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The previously introduced workflow to achieve an energetically and structurally optimized description of frontier bonds in quantum mechanical/molecular mechanics (QM/MM)‐type applications was extended into the regime of computational material sciences at the example of a layered carbon model systems. Optimized QM/MM link bond parameters at HSEsol/6‐311G(d,p) and self‐consistent density functional tight binding (SCC‐DFTB) were derived for graphitic systems, enabling detailed investigation of specific structure motifs occurring in graphene‐derived structures via quantum‐chemical calculations. Exemplary molecular dynamics (MD) simulations in the isochoric‐isothermic (NVT) ensemble were carried out to study the intercalation of lithium and the properties of the Stone–Thrower–Wales defect. The diffusivity of lithium as well as hydrogen and proton adsorption on a defective graphene surface served as additional example. The results of the QM/MM MD simulations provide detailed insight into the applicability of the employed link‐bond strategy when studying intercalation and adsorption properties of graphitic materials. [ABSTRACT FROM AUTHOR]

The bottleneck in the implementation of hybrid lithium-sodium-ion batteries is the lack of anode materials with a desired rate capability. Herein, we provide an in-depth examination of the Li-storage performance of sodium titanate nanowires as negative electrodes in hybrid Li,Na-ion batteries. Titanate nanowires were prepared by a simple and reproducible hydrothermal method. At a low reaction pressure, the well-isolated nanowires are formed, while by increasing the reaction pressure from 2 to 30 bar, the isolated nanowires tend to bundle. In nanowires, the local coordinations of Na and Ti atoms deviate from those in Na2Ti3O7 and Na2Ti6O13 and slightly depend on the reaction pressure. During the annealing at 350 °C, both Na and Ti coordinations undergo further changes. The nanowires are highly defective, and they easily crystallize into Na2Ti6O13 and Na2Ti3O7 phases. The lithium storage properties are evaluated in lithium-ion cells vs. lithium metal anode and titanate electrodes fabricated with PVDF and carboxymethyl cellulose (CMC) binders. The Li-storage by nanowires proceeds by a hybrid capacitive-diffusive mechanism between 0.1 and 2.5 V, which enables to achieve a high specific capacity. Sodium titanates accommodate Li+ by formation of mixed lithium-sodium-phase Na2−xLixTi6O13, which is decomposed to the distinct lithium phases Li0.54Ti2.86O6 and Li0.5TiO2. Contrary to lithium, the sodium storage is accomplished mainly by the capacitive reactions, and thus the phase composition is preserved during cycling in sodium ion cells. The isolated nanowires outperform bundled nanowires with respect to rate capability. [ABSTRACT FROM AUTHOR]

The results of comparative studies of the effect of current density on the average discharge voltage and specific discharge capacity of carbon electrodes based on heat-treated petroleum coke and graphite are presented. The carbon obtained by heat treatment of petroleum coke is shown to have better kinetic characteristics than graphite. The increase in the current density from 0.2 mA/cm2 (36 mA/g) to 2 mA/cm2 (364 mA/g) leads to a decrease in the discharge capacity of heat-treated petroleum coke by 26%; graphite, by 93%. When the current density is restored to 0.2 mA/cm2, the discharge capacity of carbon electrodes is also restored to its initial value. The increase in the current density is also shown to lead to increase in the average discharge voltage of lithium–carbon cells. Thus, with the increase in current density from 0.2 to 2 mA/cm2, the average discharge voltage of the lithium–carbon cells with the electrode active component of the heat-treated petroleum coke increased from 0.39 to 0.62 V; that of graphite, from 0.14 to 0.35 V. [ABSTRACT FROM AUTHOR]

CuCrO2 nanocrystals were synthesized and fabricated into mesoporous thin films to study their electrochemical properties, where a strong [Li+] dependence was observed. An anodic shift in the Cu2+/+ redox potential was observed with increased [Li+] in the electrolyte, in addition to the growth of a new redox feature at E1/2=−0.43 V vs Fc+/0. This new feature was attributed to Cu2+/+ redox chemistry accompanied by Li+ occupation in copper vacancy surface defects. The equilibrium constant and maximum charge for Li+ occupation were determined to be K=0.057 M−1 and 15.5 mC, respectively. The maximum charge was close to the expected value of 11 mC based on the measured concentration of copper vacancies. The pronounced Li+ dependent electrochemistry suggests that CuCrO2 behaves similarly to cathodes in Li‐ion batteries. Thus, chronopotentiometry experiments revealed a 7.8 mA h g−1 charge capacity at cycle 2 and increasing cycling efficiency from 83 to 91 % over 10 cycles. However, a pronounced decrease in charge capacity was observed with increased cycles, attributed to a loss in lithium‐coupled electrochemistry. These studies add to our understanding of surface defects in p‐type oxides and their effect on hole recombination in solar cell devices. [ABSTRACT FROM AUTHOR]

Lithium–manganese–oxide (Li-Mn-O) spinel is among the promising and economically viable, high-energy density cathode materials for enhancing the performance of lithium-ion batteries. However, its commercialization is hindered by its poor cyclic performance. In computational modelling, pivotal in-depth understanding of material behaviour and properties is sizably propelled by advancements in computational methods. Hence, the current work compares traditional DFT (CASTEP) and linear-scaling DFT (ONETEP) in a LiMn2O4 electronic property study to pave way for large-scale DFT calculations in a quest to improve its electrochemical properties. The metallic behaviour of LixMn2O4 (0.25 ≤ x ≤ 1) and Li2Mn2O4 was correctly determined by both CASTEP and ONETEP code in line with experiments. Furthermore, OCV during the discharge cycle deduced by both codes is in good accordance and is between 5 V and 2.5 V in the composition range of 0 ≤ x ≤ 1. Moreover, the scaling of the ONETEP code was performed at South Africa's CHPC to provide guidelines on more productive large-scale ONETEP runs. Substantial total computing time can be saved by systematically adding the number of processors with the growing structure size. The study also substantiates that true linear scaling of the ONETEP code is achieved by a systematic truncation of the density kernel. [ABSTRACT FROM AUTHOR]

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 LixGeSe 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. [ABSTRACT FROM AUTHOR]

The bottleneck in the implementation of hybrid lithium-sodium-ion batteries is the lack of anode materials with a desired rate capability. Herein, we provide an in-depth examination of the Li-storage performance of sodium titanate nanowires as negative electrodes in hybrid Li,Na-ion batteries. Titanate nanowires were prepared by a simple and reproducible hydrothermal method. At a low reaction pressure, the well-isolated nanowires are formed, while by increasing the reaction pressure from 2 to 30 bar, the isolated nanowires tend to bundle. In nanowires, the local coordinations of Na and Ti atoms deviate from those in Na2Ti3O7 and Na2Ti6O13 and slightly depend on the reaction pressure. During the annealing at 350 °C, both Na and Ti coordinations undergo further changes. The nanowires are highly defective, and they easily crystallize into Na2Ti6O13 and Na2Ti3O7 phases. The lithium storage properties are evaluated in lithium-ion cells vs. lithium metal anode and titanate electrodes fabricated with PVDF and carboxymethyl cellulose (CMC) binders. The Li-storage by nanowires proceeds by a hybrid capacitive-diffusive mechanism between 0.1 and 2.5 V, which enables to achieve a high specific capacity. Sodium titanates accommodate Li+ by formation of mixed lithium-sodium-phase Na2−xLixTi6O13, which is decomposed to the distinct lithium phases Li0.54Ti2.86O6 and Li0.5TiO2. Contrary to lithium, the sodium storage is accomplished mainly by the capacitive reactions, and thus the phase composition is preserved during cycling in sodium ion cells. The isolated nanowires outperform bundled nanowires with respect to rate capability.

Phase transitions of two-dimensional nanomaterials and their heterostructures enable many applications including electrochemical energy storage, catalysis, and memory; however, the nucleation pathways by which these transitions proceed remain underexplored, prohibiting engineering control for these applications. Here, we demonstrate that the lithium intercalation-induced 2H-1T′ phase transition in MoS2 nanosheets proceeds via nucleation of the 1T′ phase at an atomically thin heterointerface by monitoring the phase transition of MoS2/graphene and MoS2/hexagonal boron nitride (hBN) heterostructures with Raman spectroscopy in situ during intercalation. We observe that graphene–MoS2 heterointerfaces require an increase of 0.8 V in applied electrochemical potential to nucleate the 1T′ phase in MoS2 as compared to hBN–MoS2 heterointerfaces. The increased nucleation barrier at graphene–MoS2 heterointerfaces is due to the reduced charge transfer from lithium to MoS2 at the heterointerface as lithium also dopes graphene based on ab initio calculations. Furthermore, we show that the growth of the 1T′ domain propagates along the heterointerface rather than through the interior of MoS2. Our results provide the first experimental observations of the heterogeneous nucleation and growth of intercalation-induced phase transitions in two-dimensional nanomaterials and heterointerface effects on their phase transitions. These insights have implications for the design of energy technologies and devices that rely upon the phase stability of nanostructured materials. [ABSTRACT FROM AUTHOR]

Multiple polytypes of MoTe 2 with distinct structures and intriguing electronic properties can be accessed by various physical and chemical approaches. Here, we report electrochemical lithium (Li) intercalation into 1T'-MoTe 2 nanoflakes, leading to the discovery of two previously unreported lithiated phases. Distinguished by their structural differences from the pristine 1T' phase, these distinct phases were characterized using in situ polarization Raman spectroscopy and in situ single-crystal X-ray diffraction. The lithiated phases exhibit increasing resistivity with decreasing temperature, and their carrier densities are two to 4 orders of magnitude smaller than the metallic 1T' phase, as probed through in situ Hall measurements. The discovery of these gapped phases in initially metallic 1T'-MoTe 2 underscores electrochemical intercalation as a potent tool for tuning the phase stability and electron density in two-dimensional (2D) materials.

The charging and discharge characteristics of electrodes based on LiNi0.8Co0.15Al0.05O2 (NCA) and Li4Ti5O12 (LTO) are studied in LiClO4 solutions in a mixture of propylene carbonate and dimethoxyethane at the temperature from –45 to +60°С. For both materials, the discharge capacity decreases with the current increase and its dependence cannot be described by the Peukert equation. The decrease in the temperature results also in the increase in polarization, the effective energy of activation being 52 kJ/mol on the NCA electrode and only 23 kJ/mol on the LTO electrode. The possibility of using batteries based on the NCA–LTO system at the temperature down to –40°С is confirmed. [ABSTRACT FROM AUTHOR]

The realizing of new electrode materials and the modification of existing ones are important trends in the development of lithium-ion batteries. Of particular importance is the assessment of their diffusion ability, that is, the ability to provide transport of the electroactive component. For this purpose, electrochemical methods such as cyclic voltammetry, electrochemical impedance spectroscopy, potentiostatic intermittent titration, and galvanostatic intermittent titration techniques are used. The chemical diffusion coefficient D estimated in such electrode materials is shown to have a spread in values by several orders of magnitude. The main reasons for this rather significant dispersion are discussed, including the uncertainty of the estimates of the diffusion surface area and the using of various approaches to the obtaining of equations for the calculating of D. The conclusions are illustrated by examples of the D estimates in LixC6-, LixSn-, LixTiO2-, LixWO3-, LiMyMn2 –yO4-, and LiFePO4-based electrode materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • 2D multilayered Ti 3 C 2 T x MXene adsorbents were fabricated via selective Al element etching. • Li+-intercalation increased the interlayer spacing and surface area. • TCF-2 exhibited broad working pH range and excellent Nd3+ adsorption capacity (517.8 mg/g). • The Nd3+/Fe3+ selectivity of TCF-2 reached 221. • The adsorption mechanism was elucidated using different characterizations. Recovering rare earth elements (REEs) from low-concentration REE-bearing waste streams has been deemed as a sustainable approach to diversity REE supply and reduce environmental burden. However, highly selective separation of trivalent Fe3+ and Al3+ impurities during low-concentration REE processing still remains a critical challenge. In this study, two-dimensional multilayered MXene adsorbents TCFs were successfully prepared and utilized for Nd3+ adsorption via selective etching of Al element in Ti 3 AlC 2. It was found that LiF/HCl-etched TCF-2 can simultaneously realize effective Al etching, interlayer spacing expansion and in-situ Li+ intercalation. The intercalated Li+ amount was up to 4.44 wt% (6.40 mmol/g). Compared with HF-etched TCF-1, TCF-2 demonstrated boosted adsorption kinetics (2 h), large adsorption capacity (517.79 mg/g), impressively high selectivity (Nd3+/Fe3+ SF = 221, Nd3+/Ca2+ SF = 858, Nd3+/Mg2+ SF = 3545), and broad working pH range (2–7). Various experimental characterizations reveal that selective Nd3+ recovery is owing to the ion-exchange and surface complexation induced by interlayer Ti-O/Ti-OH of TCF-2. Specifically, the extended X-ray sorption fine structure (EXAFS) results, in combination with density functional theory (DFT) calculations, further confirm the Nd3+ is selectively adsorbed by forming surfaced complexes structure in the interlayer. And this is also evidenced by the decrease of Nd-O distances and high coordination number. The present results illustrate that alkaline metal ion-intercalated MXene could serve as a promising candidate to efficiently remove trivalent Fe3+ impurities for REEs recovery. [ABSTRACT FROM AUTHOR]

Developing bifunctional catalysts for both hydrogen and oxygen evolution reactions is a promising approach to the practical implementation of electrocatalytic water splitting. However, most of the reported bifunctional catalysts are only applicable to alkaline electrolyzer, although a few are effective in acidic or neutral media that appeals more to industrial applications. Here, a lithium‐intercalated iridium diselenide (Li‐IrSe2) is developed that outperformed other reported catalysts toward overall water splitting in both acidic and neutral environments. Li intercalation activated the inert pristine IrSe2 via bringing high porosities and abundant Se vacancies for efficient hydrogen and oxygen evolution reactions. When Li‐IrSe2 was assembled into two‐electrode electrolyzers for overall water splitting, the cell voltages at 10 mA cm−2 were 1.44 and 1.50 V under pH 0 and 7, respectively, being record‐low values in both conditions. [ABSTRACT FROM AUTHOR]

Lithium ion (Li+) aggregation in the amorphous tungsten oxide (a-WO x) film is the main cause of the electrochromic (EC) device failure. This has hindered a-WO x films goes towards industrialization on behalf of the giant EC performance and long-term reliability. A novel kind of electrolytes consisted of Aluminum ions (Al3+) and Lithium ions (Li+) used for electrochromic sputtered a-WO x films is presented. With the newly designed Al3+/Li+ co-existed electrolytes, the optical transmittance modulation can be largely enhanced compared with Li+, meanwhile, the problem of degradation after long-term cycling for a-WO x induced by Li ions-trapping is able to be solved. Furthermore, the utilization of Al3+ brings slow switching kinetics at the ions extraction step to the films compared with Li+, which supplies a new method to modulate the bleaching rate by applying adjustable Al3+/Li+ ratio of electrolytes and a tunable and controllable switching time is easily achieved in this work. This Al3+/Li+ co-based electrolyte opens a new way to design and control the high contrast, long-lived cycling stability and changeable switching time EC devices based on a-WO x films. [ABSTRACT FROM AUTHOR]

The V2O5 thin films has been widely studied because it has application as ionic host in electrochromic and lithium-ion batteries, two technologies that have an intimate connection with sustainability as substitutes for fossil energies and as agents for improving energy efficiency. In electrochromic technology, V2O5 is applied as a passive electrode due to its high transmittance and small contrast, and its reversibility on electrochemical reactions. To contribute to increase the optical and charge efficiency of V2O5 thin film passive electrodes, were investigated in this work the influence of the morphological properties, crystallite size and roughness, on the reversible specific charge capacity and the respective optical responses. The films morphological properties were modified by varying their thickness to the nanoscale. The films were deposited by thermal evaporation from powdered V2O5. The crystallite size and surface roughness were measured respectively by XRD and AFM. The results showed that the charge capacity is directly proportional to the surface roughness and inversely proportional to the crystallite size. The film optical contrast and the nominal transmittance shows to be improved according to their morphological properties. In conclusion, the V2O5 opto-electrochemical properties can be improved, increasing the efficiency on the light control processes.

Penetration of sodium into carbon-graphite material (CGM) specimens previously modified with lithium is studied. Sodium diffusion coefficients are calculated after treating CGM with lithium vapor and values are determined for activation energy of diffusion under different conditions. The kinetic dependences obtained make it possible to determine the sodium diffusion mechanism in modified CGM. The efficiency is demonstrated of preliminary treatment with lithium vapor that makes it possible to prevent aluminum electrolyzer cathode lining surface layer breakdown during operation. The tests on CGM specimens performed make it possible to create prerequisites for developing technology for hearth surface protection from sodium penetration during electrolysis in molten cryolite-alumina. [ABSTRACT FROM AUTHOR]

Herein, we reported a facile method to synthesize the nanostructured vanadium oxides by electrochemical deposition, followed by thermal treatment. Polymer surfactant was selected as a template agent to control the nanostructures. Nanorod-, nanoparticle- and platelet-structured vanadium oxides with different sizes were obtained by simply changing the surfactant concentrations. The crystallinity of various nanostructured vanadium oxide was confirmed by X-ray diffraction. X-ray photoelectron spectroscopic analysis reveals a mixed valence nature of vanadium specie in which the amount of V(V) and V(IV) species is not significantly affected by varying the surfactant concentrations. Cyclic-voltammetry curves show that the smallest potential separation between the cathodic and anodic peaks for the nanorod-structured vanadium oxide. The nanorod-structured vanadium oxide exhibits excellent Li-ion intercalation properties, much better than that of the nanoparticle- and platelet-structured vanadium oxides. Thus, the excellent performance with low-cost make the nanorod-structured vanadium oxide promising potential as a cathode material for the Li-ion battery applications. [ABSTRACT FROM AUTHOR]

The problem of hardening (increasing the stability) of the carbon graphite hearth lining for protection against diffusion of sodium and cryolite-alumina melt (CAM) is discussed. Analytical evaluation showed that the main protection against various kinds of electrolyte effects on the carbon graphite lining is the application of various coatings that have not found wide industrial application due to their failure. It was demonstrated that the addition of lithium to the cryolite-alumina melts has a positive effect on the properties of the carbon graphite hearth lining. It was established that lithium has an active influence on the change in the physical and operational properties of the lining as a result of the intercalation process. The improvement in the properties of the carbon graphite electrolysis cell lining was confirmed by a series of experimental studies carried out with lithium electrolytes. [ABSTRACT FROM AUTHOR]

The creation of new environmentally friendly and portable energy sources requires the development of technology used to produce lithium-ion batteries, especially their anodes. The aim of this study was to show the possibilities of the state-of-the-art ab initio approach for modeling battery anode materials. A quantum-mechanical study of the limiting filling of a silicene/aluminum anode with lithium has been performed. In this case, the changes in the structure, energy, and electronic properties of silicene that occur upon filling the anode have been studied. Lithium atoms are deposited both inside and on top of the channel formed by two parallel silicene sheets. The ratio of lithium to silicon varies in the range of 0.1–1.5. The gap in the silicene channel increases as the channel is filled with lithium. The filling of the silicene channel with lithium is associated with an increase in the Si–Si bond length in both silicene sheets without destruction of the channel. The infiltration of lithium into the space between the aluminum substrate and silicene sheet has been determined. Our calculation of the band structure has shown that, regardless of filling with lithium, the silicene-aluminum system exhibits metallic conductivity. The storage capacity of the combined anode (729 mAh g−1) significantly exceeds the capacity of graphite anodes. It was found that the top sheet of silicene acquires a negative electric charge upon significant lithium filling of the anode, exceeding the absolute value of the negative charge of the bottom sheet in contact with the aluminum substrate. Therefore, our model study has elucidated that the new silicene-aluminum anode is a promising material for the creation of a new generation of lithium-ion batteries. • The limiting filling of silicene/aluminum anode with lithium first investigated. • Ab initio molecular dynamics calculations were performed at 293 K. • The new result is a calculated capacity (729 mAh g−1) of the silicene/Al anode. • The silicene-Al system exhibits metallic conductivity even in the absence of Li. [ABSTRACT FROM AUTHOR]

Undoped and Cu-doped CeO (2.5, 5, 7.5 mol%) thin films were prepared by modified Pechini process. Grazing incidence X-ray diffraction investigations of the films revealed that the ceria thin film has a cubic structure and Cu doping inhibited the crystal growth. The presence of predominant of Ce oxidation state (CeO) and Cu in the films was approved by X-ray photoelectron spectroscopy. The fourier transform infrared spectra confirmed the metal-oxygen (Ce-O) bonding. Scanning electron microscopy images of the films displayed a crack free surface and the nano-grains regularly distributed on the surface. Atomic force microscopy analyses indicated that roughness parameters changed by Cu incorporation and 5 mol% Cu-doped CeO is the smoothest surface. Fractal dimensions of surface were calculated by box counting and triangulation method. The fractal dimension increased by Cu doping up to 5 mol% and then reduced. The optical transmittance was enhanced and the absorption edge was shifted to lower wavelength by Cu doping. The refractive indices and extinction coefficients which were determined using theoretical approach were decreased by Cu doping. Photoluminescence emission intensity of CeO thin film was quenched by Cu doping. The electrochemical behavior of the films was examined in 1 M LiClO/propylene carbonate electrolyte. The total charge density of ceria thin film increased by Cu doping and 5 mol% Cu-doped CeO film had the highest ion storage capacitance. The fractal analyses showed that the surface morphology affected the Li ion diffusion behavior of CeO:Cu thin films. Graphical Abstract: [ABSTRACT FROM AUTHOR]

The adsorption of CO 2 and H 2 O on divacanacy (DV) defected graphene cluster, and its bilayer counterpart is investigated using first-principles calculations. Both single and bilayer DV graphene cluster, are functionalised with H and F atoms. On these sheets the gas molecules are physisorbed, and the divacancy defect effectively improves the adsorption of CO 2 , while fluorination enhances the hydrophobicity of the graphene cluster. Among the convex and concave curvature regions induced due to the DV defect, the adsorption of the gas molecules on the concave meniscus is more favourable. Fluorine termination induces 73% reduction in Henry law constants for H 2 O, while for the CO 2 molecule it increases by 8%, which indicates the DV defective sheet is a better candidate for CO 2 capture compared to the STW defective sheet. Besides, both AA and AB divacant defect bilayer sheets are equally stable, wherein AA stacking results in a cavity between the sheets, while in AB stacking, the layers slide one over the other. Nevertheless, both these bilayer sheets are comparatively stabler than the monolayer. However, intercalation of lithium decreases the interlayer separation, particularly in AA stacking, which enhances the CO 2 adsorption, but in the Bernal stacking enhances it hydrophobicity. [ABSTRACT FROM AUTHOR]

Several spent Li-ion batteries were manually dismantled and their components were uncurled and separated. The chemical composition of each battery's component was determined by atomic absorption spectroscopy. Among several ways to separate cathode material from the collector, the alkali dissolution treatment was selected as the most effective one. After both complete separation and acid leaching steps, the co-precipitation method, followed by a thermal treatment (700 °C or 850 °C), was used to resynthesize cathode material LiCo 0.415 Mn 0.435 Ni 0.15 O 2 . Its structure and morphology were characterized by XRD, Raman spectroscopy and SEM-EDS methods. The electrochemical behavior of recycled cathode materials was examined by cyclic voltammetry and chronopotentiometry in both LiNO 3 and NaNO 3 aqueous solutions. High sodium storage capacity, amounting to 93 mAh g −1 , was measured galvanostatically at a relatively high current of ∼100 mA g −1 . Initial lithium intercalation capacity of ∼64 mAh g −1 , was determined potentiodynamically at very high scan rate of 20 mV s −1 (∼40 C). Somewhat lower initial capacity of ∼30 mAh g −1 , but much lower capacity fade on cycling, was found for sodium intercalation at the same scan rate. The differences in the Li and Na charge storage capability were explained in terms of ion rearrangement during charging/discharging processes. [ABSTRACT FROM AUTHOR]

In this work, lithium plating is investigated by means of voltage relaxation and in situ neutron diffraction in commercial lithium-ion batteries. We can directly correlate the voltage curve after the lithium plating with the ongoing phase transformation from LiC 12 to LiC 6 according to the neutron diffraction data during the relaxation. Above a threshold current of C/2 at a temperature of −2 °C, lithium plating increases dramatically. The results indicate that the intercalation rate of deposited lithium seems to be constant, independent of the deposited amount. It can be observed that the amount of plating correlates with the charging rate, whereas a charging current of C/2 leads to a deposited amount of lithium of 5.5% of the charge capacity and a current of 1C to 9.0%. [ABSTRACT FROM AUTHOR]