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At least 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Effect of Fluoroethylene Carbonate Additives on the Initial Formation of the Solid Electrolyte Interphase on an Oxygen-Functionalized Graphitic Anode in Lithium-Ion Batteries

The formation of a solid electrolyte interphase (SEI) at the electrode/electrolyte interface substantially affects the stability and lifetime of lithium-ion batteries (LIBs). One of the methods to improve the lifetime of LIBs is by the inclusion of additive molecules to stabilize the SEI. To understand the effect of additive molecules on the initial stage of SEI formation, in this work we compare the decomposition and oligomerization reactions of a fluoroethylene carbonate (FEC) additive on a range of oxygen-functionalized graphitic anodes to those of an ethylene carbonate (EC) organic electrolyte. A series of density functional theory (DFT) calculations augmented by ab initio molecular dynamics (AIMD) simulations reveal that EC decomposition on an oxygen-functionalized graphitic ($11\bar{2}0$) edge facet through a nucleophilic attack on an ethylene carbon site (C E ) of an EC molecule (S2 mechanism) is spontaneous during the initial charging process of LIBs. However, decomposition of EC through a nucleophilic attack on a carbonyl carbon (C C ) site (S1 mechanism) results in alkoxide species regeneration that is responsible for continual oligomerization along the graphitic surface. In contrast, FEC prefers to decompose through an S1 pathway, which does not promote alkoxide regeneration. Including FEC as an additive is thus able to suppress alkoxide regeneration and results in a smaller and thinner SEI layer that is more flexible toward lithium intercalation during the charging/discharging process. In addition, we find that the presence of different oxygen functional groups at the surface of graphite dictates the oligomerization products and the LiF formation mechanism in the SEI.

25 ENERGY STORAGE↗
DOE OSTI2025

Characterizing the surface compositions of supported bimetallic PtSn clusters: Effects of cluster-support interactions and surface adsorbates

PtSn bimetallic clusters on TiO2(110) and highly oriented pyrolytic graphite (HOPG) surfaces have been characterized by scanning tunneling microscopy, low energy ion scattering (LEIS), Xray photoelectron spectroscopy, and temperature programmed desorption (TPD); density functional theory (DFT) calculations have also been performed to better understand adsorption of CO and D2 on the PtSn surfaces. On TiO2 at coverages of 2 ML of Pt and 2 ML of Sn, exclusively bimetallic clusters are formed for both orders of deposition because clusters of the first metal completely cover the surface such that all atoms of the second metal are incorporated into the existing clusters. In contrast, on HOPG, the high mobility and weak cluster-support interactions on HOPG result in much larger 2 ML monometallic clusters (~30 Å high) that do not completely cover the surface, and deposition of the second metal produces larger clusters as well as smaller ones. Despite the difference in cluster morphologies for the different orders of deposition and supports, the LEIS experiments demonstrate that in all cases, the PtSn clusters are rich in Sn at the surface, as expected based on the lower surface free energy for Sn compared to Pt. Furthermore, the +0.2 eV shift in the Sn(3d5/2) binding energy observed on all surfaces in the presence of Pt is consistent with PtSn alloy formation. Deposition of 2 ML of Sn on TiO2 produces two-dimensional clusters with oxidation of Sn and reduction of titania at the clustersupport interface, but addition of Pt to the Sn clusters causes Sn to diffuse away from this interface, leaving Sn in the metallic state. TPD experiments on 2 ML Pt/TiO2 with increasing coverages of Sn show that the number of adsorption sites for D2 sharply decreases to nearly zero at 0.5 ML, while CO adsorption decreases to zero only at much higher Sn coverages of 2 ML. DFT studies for Sn modified Pt surfaces and bulk structures demonstrate that for CO adsorption at low Sn coverages (<0.25 ML), the strong Pt-CO interactions induce diffusion of Pt to the cluster surface and the formation of a bulk Pt3Sn alloy, whereas D2 adsorption does not lead to interactions with the Pt surface that are strong enough to induce alloy formation. A single Sn adatom prevents D2 adsorption on four neighboring Pt atoms via site-blocking and the donation of electron density to Pt.

Li, Fangliang↗
DOE OSTI2025

Electronic density of states as the descriptor of elastic bond strength, ductility, and local lattice distortion in BCC refractory alloys

Although electronic density of states (DOS) is fundamental to materials properties, its general relationship to mechanical properties of alloys is not well established. In this paper, using density functional theory (DFT) calculations, we show that the electronic occupancy at the Fermi level, N(E f ), obtained from DOS is a key descriptor of alloy strength and ductility. Our comprehensive analysis of numerous body centered cubic (BCC) refractory high entropy alloys (RHEAs) shows an overwhelming correlation that low N(E f ) indicates strong bonds that have high stiffness resulting in high elastic constants. High bond stiffness indicates presence of covalent nature of bonds that are directional in nature resulting in resistance to deformation leading to high bulk (B) and shear (G) moduli. Consequently, N(E f ) provides a direct correlation to the tendency of alloy ductility evidenced in the Pugh ratio (G/B). As stiffer bonds result in lower local lattice distortion (LLD), N(E f ) are LLD are also found to be corelated which opens up a correlation to solid solution strengthening and yield strength. Thus, this work unveils fundamental correlations between N(E f ) and (1) elastic bond strength, (2) ductility, and (3) LLD. These correlations open opportunities for the design of high strength high ductile RHEAs.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Spot the difference: hydrogen adsorption and dissociation on unsupported platinum and platinum-coated transition metal carbides

Hydrogenation reactions are involved in several processes in heterogeneous catalysis. Platinum is the best-known catalyst; however, there are limitations to its practical use. Therefore, it is necessary to explore alternative materials and transition metal carbides (TMCs) have emerged as potential candidates. We explore the possibility of using cheap TMCs as supports for a Pt monolayer, aiming to reduce the amount of the noble metal in the catalyst without a significant loss of its activity towards H 2 dissociation. Hence, analyzing H 2 dissociation from a fundamental point of view is a necessary step towards a further practical catalyst. By means of periodic DFT calculations, we analyze H 2 adsorption and dissociation on Pt/β-Mo 2 C and Pt/α-WC surfaces, as a function of hydrogen surface coverage ( Θ H ), resembling a more realistic model of a catalyst. H 2 dissociation rates were analyzed as a function of the reaction temperature. Overall, the results show that Pt/C-WC and Pt/Mo-Mo 2 C have a Pt-like behavior for H 2 dissociation at Θ H > 1/2 ML. At a particular temperature of 298 K, Pt/C-WC and Pt/Mo-Mo2C have low energy barriers for H 2 * → 2H* (0.13 and 0.11 eV, respectively), close to the value of Pt (0.06 eV). For the highest coverage, i.e. Θ H = 1, Pt/C-WC has a lower activation energy and a higher reaction rate than Pt. Finally, the H 2 dissociation rate is higher in Pt/Mo-Mo 2 C than in Pt when increasing the temperature above 298 K. Our results put Pt/C-WC and Pt/Mo-Mo 2 C under the spotlight as potential catalysts for H 2 dissociation, with a similar performance to Pt, paving the way for further experimental and/or theoretical studies, addressing the capability of Pt/TMC as practical catalysts in hydrogenation reactions.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Intermediate Bandgap (IB) Cu 3 VS x Se 4−x Nanocrystals as a New Class of Light Absorbing Semiconductors

A new family of highly uniform, cubic-shaped Cu 3 VS x Se 4−x (CVSSe; 0 ≤ x ≤ 4) nanocrystals based on earth-abundant materials with intermediate bandgaps (IB) in the visible range is reported, synthesized via a hot-injection method. The IB transitions and optical band gap of the novel CVSSe nanocrystals are investigated using ultraviolet-visible spectroscopy, revealing tunable band gaps that span the visible and near-infrared regimes. The composition-dependent relationships among the crystal phase, optical band gap, and photoluminescence properties of the novel IB semiconductors with progressive substitution of Se by S are examined in detail. High-resolution transmission electron microscopy and scanning electron microscopy characterization confirm the high crystallinity and uniform size (~19.7 nm × 17.2 nm for Cu 3 VS 4 ) of the cubic-shaped nanocrystals. Density functional theory (DFT) calculations based on virtual crystal approximation support the experimental findings, showing good agreement in lattice parameters and band gaps across the CVSSe series and lending confidence that the targeted phases and compositions have been successfully realized. A current conversion efficiency, i.e., incident photon-to-current efficiency, of 14.7% was achieved with the p-type IB semiconductor Cu 3 VS 4 . These novel p-type IB semiconductor nanocrystals hold promise for enabling thin film solar cells with efficiencies beyond the Shockley–Queisser limit by allowing sub-band-gap photon absorption through intermediate-band transitions, in addition to the conventional direct-band-gap transition.

Cu3VSxSe4−x↗
DOE OSTI2025

Direct Comparison of the Activity and Selectivity of Rh 1 Cu and Ni 1 Cu Single-Atom Alloy Sites for Ethanol Decomposition

Ethanol is an important source of clean hydrogen, acetaldehyde, acetic acid, acetate esters, and light hydrocarbons. Controlling the divergent reaction pathways to these products requires understanding how different active sites influence the elementary steps involved. Herein, we present a combined surface science, theory, and nanoparticle catalysis study demonstrating how two single-atom dopants (Rh and Ni) in a Cu host can distinctively alter the selectivity of alcohol conversion. Specifically, our model studies reveal that ethanol reacts on Ni 1 Cu single-atom alloys to selectively produce acetaldehyde, whereas methane and CO are also formed on Rh 1 Cu single-atom alloys. Interestingly, these different reactivities are in contrast to the behavior of the pure metals as Ni(111) and Rh(111) surfaces favor methane/CO and surface carbon/CO, respectively. DFT calculations of reaction pathways and simulated product desorption based on microkinetic analyses explain these reactivity differences, demonstrating that C–C cleavage leading to methane formation has a lower barrier on Rh single-atom sites. To test the catalytic relevance of these fundamental results we synthesized and characterized supported Ni 1 Cu and Rh 1 Cu single-atom alloy nanoparticles with dopant:Cu ratios of 1:200. Flow reactor results revealed that both Ni and Rh increased ethanol conversion over Cu and that Ni 1 Cu catalysts were >99.9% selective to acetaldehyde, while Rh 1 Cu also produced 0.6%–2.6% of equimolar methane and CO between 433 and 493 K, demonstrating that C–C bond cleavage is enabled by isolated Rh sites. Furthermore, these catalytic results bridge the pressure and materials gaps, and together, this study provides insights into how different isolated dopant sites promote different catalytic pathways.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Unraveling the CO Oxidation Mechanism over Highly Dispersed Pt Single Atom on Anatase TiO 2 (101)

Catalysts with noble metals deposited as single atoms on metal oxide supports have recently been studied extensively due to their maximized metal utilization and potential for performing difficult chemical conversions owing to their unique electronic properties. Understanding of the reaction mechanisms on supported single-metal atoms is still limited but is highly important for designing more efficient catalysts. In this study, we report the complexity of the CO oxidation reaction mechanism on Pt single atoms supported on anatase TiO 2 (Pt SA /a-TiO 2 ) by coupling density functional theory (DFT) calculations and microkinetic analysis with kinetic measurements, in situ/operando infrared, and X-ray absorption spectroscopies. Starting from the adsorbed Pt SA occupying an O vacancy induced by reductive pretreatment, we show that CO oxidation follows a complex mechanism consisting of initiation steps to reorganize the active site and multibranch reactive cycles, with the Pt SA /a-TiO 2 catalyst not returning to its initial configuration. The initiation step consists of CO and O 2 adsorption healing the O vacancy, followed by CO oxidation using gas-phase CO to form Pt(CO). The reactive cycle alternates O 2 adsorption and dissociation to oxidize the catalyst to Pt(O)(O)(CO) and branching pathways of competing Langmuir–Hinshelwood (LH)- or Eley–Rideal (ER)-type CO oxidation steps to reduce it again to Pt(CO). In situ/operando infrared experiments, including cryogenic CO adsorption and isotopic CO exchange, confirm the combined involvement of strongly adsorbed CO and gas-phase CO in an Eley–Rideal step along the reaction cycle. Microkinetic modeling shows that Pt single atoms are present in a mixture of Pt(CO), Pt(CO)(O 2 ), Pt(O)(CO)(O 2 ), and Pt(CO)(CO 3 ) structures as the main intermediates during steady-state CO oxidation, all having the C–O vibrational stretch close to the experimentally observed value of 2115 cm –1 . Microkinetic modeling also shows that the fractional orders of CO and O 2 measured experimentally originate from multiple steps with a high degree of rate control and not from a simple competitive adsorption. The results demonstrate the complex reaction pathways that even CO oxidation on a simple single-atom system can follow, providing mechanistic insights for designing efficient Pt-based single-atom catalysts. Here, we further show that microkinetic modeling results are sensitive to changes in energies of intermediate and transition states within errors of density functional theory, which can ultimately lead to incorrect conclusions regarding the reaction pathways and most abundant reaction intermediates if not accounted for by experiments.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Feasibility of Prelithiation in LiFePO 4

Lithium iron phosphate (LiFePO 4 ) is widely applied as the cathode material for the energy storage Li-ion batteries due to its low cost and high cycling stability. However, the low theoretical specific capacity of LiFePO 4 makes its initial capacity loss more concerning. Therefore, lithium compensation by way of prelithiation and applications of sacrificial Li-rich additives in LiFePO 4 is imminent in elevating the energy density and/or prolonging the lifetime of the LiFePO 4 -based Li-ion batteries (LIBs). Prelithiation in LiFePO 4 is herein carried out by electrochemical and chemical methods and its feasibility is proved on the basis of the electrochemical evaluations such as the initial charge capacity and the cycling stability. In addition, the site of the pre-intercalated Li-ions is found via comprehensive physical characterizations and the density functional theory (DFT) calculations. Furthermore, these findings open a new avenue for elevating the energy density and/or prolonging the lifetime of the high-energy-density batteries.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Crystallographic Insight of Reduced Lattice Volume Expansion in Mesoporous Cu 2+ -Doped TiNb 2 O 7 Microspheres during Li + Insertion

TiNb 2 O 7 represents a promising anode material for lithium-ion batteries (LIBs), but its practical applications are currently hampered by the non-negligible volumetric expansion and contraction during the charge/discharge process and the sluggish ion/electron kinetics. Here a combination technique is reported by systematically optimizing the porous and spherical morphology, crystal structure, and surface decoration of mesoporous Cu 2+ -doped TiNb 2 O 7 microspheres to enhance the electrochemical Li + storage performance and stability simultaneously. The Cu 2+ dopants preferentially replace Ti 4+ in crystal lattices, which decreases the Li + diffusion barrier and increases the electronic conductivity, as confirmed by density functional theory (DFT) calculation and demonstrated by diverse electrochemical characterizations. The successful Cu 2+ doping significantly reduces the lattice expansion coefficient from 7.26% to 4.61% after Li + insertion along the b-axis of TiNb 2 O 7 , as visualized from in situ and ex situ XRD analysis. The optimal 5% Cu 2+ -doped TiNb 2 O 7 with surface coating of N-doped carbon exhibits significantly enhanced specific capacity and rate and cyclic performances in both half- and full-cell configurations, demonstrating an excellent electrochemical behavior for fast-charging LIB applications.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Exploring the Structural, Dynamic, and Functional Properties of Metal–Organic Frameworks through Molecular Modeling

This review spotlights the role of atomic-level modeling in research on metal-organic frameworks (MOFs), especially the key methodologies of density functional theory (DFT), Monte Carlo (MC) simulations, and molecular dynamics (MD) simulations. The discussion focuses on how periodic and cluster-based DFT calculations can provide novel insights into MOF properties, with a focus on predicting structural transformations, understanding thermodynamic properties and catalysis, and providing information or properties that are fed into classical simulations such as force field parameters or partial charges. Classical simulation methods, highlighting force field selection, databases of MOFs for high-throughput screening, and the synergistic nature of MC and MD simulations, are described. By predicting equilibrium thermodynamic and dynamic properties, these methods offer a wide perspective on MOF behavior and mechanisms. Additionally, the incorporation of machine learning (ML) techniques into quantum and classical simulations is discussed. These methods can enhance accuracy, expedite simulation setup, reduce computational costs, as well as predict key parameters, optimize geometries, and estimate MOF stability. By charting the growth and promise of computational research in the MOF field, the aim is to provide insights and recommendations to facilitate the incorporation of computational modeling more broadly into MOF research.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Engineering collinear magnetization in hexagonal LuFeO 3 and magnetoelectric control of skyrmions in hexagonal 2D epilayers

Cubic, perovskite-structure ABO 3- and A 1–x A’ x BO 3 -type oxides have been investigated extensively while their hexagonal structure versions have not, even though they are multiferroic and can form heterostructures with hexagonal 2D materials. In particular, multiferroic 2D epilayers may lead to strong magnetoelectric coupling. Hexagonal RFeO 3 ferrites, where R is a rare-earth element (Lu, Yb, etc.), are excellent candidates, but their ferromagnetism isweak. In this paper, we employ density-functional-theory (DFT) calculations and first show that heavy electron doping of hexagonal LuFeO 3 (h-LFO), namely Lu 1–x Hf x FeO 3 (h-LHFO), leads to spin-disproportionation of the Fe sublattices and, especially for x = 1/2 and 2/3, to robust, room-temperature, out-of-plane, collinear ferrimagnetism that is stabilized by a Jahn-Teller metal-to-insulator transition. We then show that h-LHFO/h-2D heterostructures, where h-2D is the FE/ FM monolayer MnSTe, stabilize skyrmions without an external magnetic field and control their chirality by an external electric field through the h-LHFO polarization, opening up a new realm for magnetoelectric applications.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Construction of a Pt‐CeO x Interface for the Electrocatalytic Hydrogen Evolution Reaction

Abstract The creation of metal‐metal oxide interfaces is an important approach to fine‐tuning catalyst properties through strong interfacial interactions. This article presents the work on developing interfaces between Pt and CeO x that improve Pt surface energetics for the hydrogen evolution reaction (HER) within an alkaline electrolyte. The Pt‐CeO x interfaces are formed by depositing size‐controlled Pt nanoparticles onto a carbon support already coated with ultrathin CeO x nanosheets. This interface structure facilitates substantial electron transfer from Pt to CeO x , resulting in decreased hydrogen binding energies on Pt surfaces, and water dissociation for the HER, as predicted by the density functional theory (DFT) calculations. Electrochemical testing indicates that both Pt specific activity and mass activity are improved by a factor of 2 to 3 following the formation of Pt‐CeO x interfaces. This study underscores the significance and potential of harnessing robust interfacial effects to enhance electrocatalytic reactions.

25 ENERGY STORAGE↗
DOE OSTI2025

Enhancing Metal‐Support Interactions of Ru Catalysts via Relaxation of Oxygen Vacancies for Hydrogen Production

The stability of Ru-based catalysts under harsh electrochemical conditions is a critical challenge limiting their practical application in energy conversion systems. In this study, Ru catalysts supported on ZrO 2-x , CeO 2-x , and ZrCeO 2-x are synthesized via pyrolysis of metal-organic frameworks (MOFs) and systematically evaluated to elucidate the role of support interactions on catalytic performance and durability. Advanced characterization techniques, including HR-TEM, XRD, XPS, and EXAFS, revealed that Ru-ZrCeO 2-x exhibited superior structural stability compared to Ru-ZrO 2-x and Ru-CeO 2-x , particularly under high-potential sweep (HPS) conditions. The incorporation of Ce into ZrO 2-x is shown to stabilize oxygen vacancies and enhance the interaction between Ru catalyst and the support, thereby mitigating catalyst degradation. Density functional theory (DFT) calculations further confirmed that Ce doping decreases formation energy of the oxygen vacancy, providing a thermodynamically favorable environment for Ru stabilization. This work demonstrates the promise of ZrCeO 2-x as a robust support material for Ru-based catalysts, advancing their potential for durable and efficient energy applications.

hydrogen evolution reaction↗
DOE OSTI2026

Colloidal Synthesis of Palladium Nanocluster‐Decorated Cs 3 Sb 2 Cl 9 Perovskite Heterostructural Nanorods for Enhanced CO 2 Photoreduction

Developing efficient and sustainable photocatalysts for CO 2 reduction remains a significant challenge, particularly with environmentally benign materials. Here, in this study, we report the first one-step synthesis of metal–lead-free perovskite heterostructural nanocrystals by decorating Cs 3 Sb 2 Cl 9 perovskite nanorods with size-controlled Pd nanoclusters via a one-step hot-injection method. The resulting Pd-Cs 3 Sb 2 Cl 9 heteronanorods (HNRs) exhibit strong interfacial electronic coupling, enhanced charge separation, and excellent colloidal stability. Transient absorption spectroscopy and DFT calculations reveal a built-in electric field that drives directional electron transfer from the perovskite host to the Pd domains. Under UV irradiation, the Pd-Cs 3 Sb 2 Cl 9 HNRs demonstrate excellent CO 2 photoreduction activity with high CH 4 selectivity, achieving a record apparent quantum yield (AQY) of 2.62% among halide perovskite nanocrystal-based systems with a large electronic yield of 689.3 ± 12.2 µmol·g cat −1 . In situ spectroscopic monitoring and Gibbs free energy analysis further unveil a Pd-facilitated reaction pathway involving stabilization of key intermediates. This work introduces a new class of lead-free perovskite-based heterostructures through a facile one-step synthesis strategy and offers a new design principle for next-generation photocatalysts for solar fuel production.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2026

Atomic‐Scale Surface Imaging of Bulk Epitaxial CsPbBr 3 Perovskite Single Crystals on Mica Using Light Assisted Scanning Tunneling Microscopy at Low‐Temperature (80 K)

Epitaxial single-crystalline CsPbBr 3 perovskite films on mica, prepared ex situ, are explored using a low-temperature scanning tunneling microscope (STM) by probing the unoccupied electronic states of their surface in ultra-high vacuum (UHV) at 80 K. Light-assisted STM measurements under a broadband illumination with visible light were employed to enhance and stabilize surface conductivity. STM imaging across the surface of macroscopic bulk CsPbBr 3 films reveals large flat terraces characterized by a specific type of surface reconstruction, consisting of parallel rows of U-shaped atomic nanostructures. These structures are spaced by 12 Å and exhibit an internal feature size of 5.1 Å. Density functional theory (DFT) calculations reproduce the experimental observations and reveal a competition between different orthorhombic CsPbBr 3 (110) surface reconstructions: a Cs-rich structure, identified as the most energetically stable, and three alternative Pb–Br-rich reconstructions, which are slightly higher in energy yet remain consistent with the STM data. Additional analyses that explicitly account for the mica substrate exclude the cubic CsPbBr 3 phase and other orthorhombic surface orientations, while showing that variations in the mica surface termination do not alter the preferred CsPbBr 3 (110) reconstruction. In conclusion, this combined approach thereby confirms our assignment and resolves previous STM interpretations of CsPbBr 3 .

36 MATERIALS SCIENCE↗
DOE OSTI2020

A Novel NASICON‐Type Na 4 MnCr(PO 4 ) 3 Demonstrating the Energy Density Record of Phosphate Cathodes for Sodium‐Ion Batteries

Abstract Sodium‐ion batteries (SIBs) have attracted incremental attention as a promising candidate for grid‐scale energy‐storage applications. To meet practical requirements, searching for new cathode materials with high energy density is of great importance. Herein, a novel Na superionic conductor (NASICON)‐type Na 4 MnCr(PO 4 ) 3 is developed as a high‐energy cathode for SIBs. The Na 4 MnCr(PO 4 ) 3 nanoparticles homogeneously embedded in a carbon matrix can present an extraordinary reversible capacity of 160.5 mA h g −1 with three‐electron reaction at ≈3.53 V during the Na + extraction/insertion process, realizing an unprecedentedly high energy density of 566.5 Wh kg −1 in the phosphate cathodes for SIBs. It is intriguing to reveal the underlying mechanism of the unique Mn 2+ /Mn 3+ , Mn 3+ /Mn 4+ , and Cr 3+ /Cr 4+ redox couples via X‐ray absorption near‐edge structure spectroscopy. The whole electrochemical reaction undergoes highly reversible single‐phase and biphasic transitions with a moderate volume change of 7.7% through in situ X‐ray diffraction and ex situ high‐energy synchrotron X‐ray diffraction. Combining density functional theory (DFT) calculations with the galvanostatic intermittent titration technique, the superior performance is ascribed to the low ionic‐migration energy barrier and desirable Na‐ion diffusion kinetics. The present work can offer a new insight into the design of multielectron‐reaction cathode materials for SIBs.

Zhang, Jian↗