High Configurational Entropy Research Articles

Critical Role of Configurational Disorder in Stabilizing Chemically Unfavorable Coordination in Complex Compounds.

The crystal structure of a material is essentially determined by the nature of its chemical bonding. Consequently, the atomic coordination intimately correlates with the degree of ionicity or covalency of the material. Based on this principle, materials with similar chemical compositions can be successfully categorized into different coordination groups. However, counterexamples have recently emerged in complex ternary compounds. For instance, covalent IB-IIIA-VIA2 compounds, such as AgInS2, prefer a tetrahedrally coordinated structure (TCS), while ionic IA-VA-VIA2 compounds, such as NaBiS2, would favor an octahedrally coordinated structure (OCS). One naturally expects that IB-VA-VIA2 compounds with intermediate ionicity or covalency, such as AgBiS2, should then have a mix-coordinated structure (MCS) consisting of covalent AgS4 tetrahedra and ionic BiS6 octahedra. Surprisingly, only the experimental presence of the OCS was observed for AgBiS2. To resolve this puzzle, we perform first-principles studies of the phase stabilities of ternary compounds at finite temperatures. We find that AgBiS2 indeed prefers MCS at the ground state, in agreement with the typical expectation, but under experimental synthesis conditions, disordered OCS becomes energetically more favorable because of its low mixing energy and high configurational entropy. Our work elucidates the critical role of configurational disorder in stabilizing chemically unfavorable coordination, providing a rigorous rationale for the anomalous coordination preference in IB-VA-VIA2 compounds.

Single‐Source Precursor Synthesis of a Compositionally Complex Early Transitional Metal Carbonitride (Ti,Zr,Hf,Nb,Ta)NxC1‐x

Compositionally complex transitional metal nitrides are possible candidates for ultra‐high temperature usage and are known for their superior properties due to the high configuration entropy. It is often difficult to synthesize pure metal nitrides in bulk, due to significant oxygen contamination; hence, they are synthesized mainly as thin films through magnetron sputtering, CVD or surface nitridation of high entropy alloys. The present paper reports on a single‐phase compositionally complex ceramic, i.e., (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)NxC1‐x, that was synthesized for the first time by employing an organometallic precursor route and using a double ammonolysis process. A multidisciplinary approach was performed to study these compositionally complex nitride and carbonitride systems, including experimental and theoretical investigations.This article is protected by copyright. All rights reserved.

Phases, stabilities, and oxide ion conductions of multiple lanthanide and tungsten co–doped δ-Bi2O3-based materials: From low to high configuration entropy

In this work, a series of multiple lanthanide and tungsten co-doped fluorite structured (Bi2O3)0.95-x(Ho0.4Er0.4Tm0.4Yb0.4Lu0.4O3)x(WO3)0.05 (x = 0.1, 0.2, 0.3, 0.4) and (Bi2O3)0.26(Ho0.5Er0.5Tm0.5Yb0.5O3)0.48(WO3)0.26 materials were prepared by traditional solid-state reaction method. The phases, stabilities, and electrical properties of these materials were thoroughly studied. The results revealed that under high oxygen partial pressure, CO2, or inert atmospheres, all these samples had excellent long term thermal stability and chemical stability, and the samples of (Bi2O3)0.95-x(Ho0.4Er0.4Tm0.4Yb0.4Lu0.4O3)x(WO3)0.05 (x = 0.1, 0.2, 0.3, 0.4) with low or mediate configuration entropies showed pure and high oxide ion conductivities, e.g. ∼2.6 × 10−2 S/cm at 600 °C for the sample x = 0.2. Whereas, for the (Bi2O3)0.26(Ho0.5Er0.5Tm0.5Yb0.5O3)0.48(WO3)0.26 sample with high configuration entropy, pure ionic conduction occurred only within a narrow temperature range (700−750 °C) under the N2 atmosphere. Under strong reducing condition, only the high-entropy sample (Bi2O3)0.26(Ho0.5Er0.5Tm0.5Yb0.5O3)0.48(WO3)0.26 showed high phase and chemical stabilities, but would introduce strong electronic conduction rise from the reduction of the high content W6+. While for (Bi2O3)0.95-x(Ho0.4Er0.4Tm0.4Yb0.4Lu0.4O3)x(WO3)0.05 with low or mediate configuration, phase decompositions with impurities of Bi metal and HoH2 were observed under strong reducing atmosphere, accompany with obviously decreased conductivities. Therefore, we provided here a comprehensive understanding for the multiple components doped Bi2O3-based materials with configuration entropy from low to high on their phases, stabilities, and electrical properties, and suggested a new strategy for designing and stabilizing bismuth-oxide-based materials.

Entropy Engineering Constrain Phase Transitions Enable Ultralong-life Prussian Blue Analogs Cathodes.

Prussian blue analogs (PBAs) are considered as one of the most potential electrode materials in capacitive deionization (CDI) due to their unique 3D framework structure. However, their practical applications suffer from low desalination capacity and poor cyclic stability. Here, an entropy engineering strategy is proposed that incorporates high-entropy (HE) concept into PBAs to address the unfavorable multistage phase transitions during CDI desalination. By introducing five or more metals, which share N coordination site, high-entropy hexacyanoferrate (HE-HCF) is constructed, thereby increasing the configurational entropy of the system to above 1.5R and placing it into the high-entropy category. As a result, the developed HE-HCF demonstrates remarkable cycling performance, with a capacity retention rate of over 97% after undergoing 350 ultralong-life cycles of adsorption/desorption. Additionally, it exhibits a high desalination capacity of 77.24mg g-1 at 1.2V. Structural characterization and theoretical calculation reveal that high configurational entropy not only helps to restrain phase transition and strengthen structural stability, but also optimizes Na+ ions diffusion path and energy barrier, accelerates reaction kinetics and thus improves performance. This research introduces a new approach for designing electrodes with high performance, low cost, and long-lasting durability for capacitive deionization applications.

High-entropy engineering of the crystal and electronic structures in a Dirac material

Dirac and Weyl semimetals are a central topic of contemporary condensed matter physics, and the discovery of new compounds with Dirac/Weyl electronic states is crucial to the advancement of topological materials and quantum technologies. Here we show a widely applicable strategy that uses high configuration entropy to engineer relativistic electronic states. We take the AMnSb2 (A = Ba, Sr, Ca, Eu, and Yb) Dirac material family as an example and demonstrate that mixing of Ba, Sr, Ca, Eu and Yb at the A site generates the compound (Ba0.38Sr0.14Ca0.16Eu0.16Yb0.16)MnSb2 (denoted as A5MnSb2), giving access to a polar structure with a space group that is not present in any of the parent compounds. A5MnSb2 is an entropy-stabilized phase that preserves its linear band dispersion despite considerable lattice disorder. Although both A5MnSb2 and AMnSb2 have quasi-two-dimensional crystal structures, the two-dimensional Dirac states in the pristine AMnSb2 evolve into a highly anisotropic quasi-three-dimensional Dirac state triggered by local structure distortions in the high-entropy phase, which is revealed by Shubnikov–de Haas oscillations measurements.

Violation of the Cauchy–Born rule in multi-principal element alloys

Multi-principal element alloys are a novel class of materials that are formed by combining multiple elements in high concentrations and show exceptional properties compared to conventional alloys. These alloys have high configurational entropy due to inherent atomic disorder. The Cauchy–Born rule is a popular homogenization method for linking atomistic to continuum length scales. In this Letter, we use ab initio density functional theory calculations to report that the Cauchy–Born rule, which holds in conventional alloys in the absence of defects, is not valid in multi-principal element alloys. The violation of the Cauchy–Born rule in these alloys is attributed to the presence of atomic disorder due to which the deformations are inhomogeneous. Our results also show the deviations in deformation are related to the magnitude of the stretch and shear by power laws.

Designing Strong Polarity and High Configurational Entropy Flexible Units toward Excellent Ultraviolet Nonlinear Optical Materials

AbstractPolar materials play a crucial role in numerous essential fields; however, efficiently synthesizing them remains a significant challenge. In this study, a viable approach is proposed to enhance the probability of discovering polar materials by developing new functional basic units (FBUs) with strong polarity and high configurational entropy. To validate this approach, a site‐modification strategy is applied to the high configurational entropy flexible (C3H2O4)2− FBU, resulting in the development of four new polar‐enhancing FBUs: (C3(CH3)2O4)2−, (C3F2O4)2−, (C3H(OH)O4)2−, and (C3HFO4)2−. Moreover, 11 new compounds through temperature‐driven conformational changes in FBUs are successfully synthesized. Among these, the proportion of polar structures reaches an impressive 54%. Remarkably, all of these novel polar compounds exhibit outstanding nonlinear optical (NLO) properties. The [Li2C3(CH3)2O4]2·3H2O demonstrates the rare coexistence of a moderate birefringence (0.071@514 nm), short UV cutoff edge (210 nm), and the strongest second harmonic generation (SHG) effect (6.5 × KDP) among ionic‐organic fourth harmonic generation crystals. Preliminary laser experiments have also proven its potential practical value as a fourth harmonic generation crystal. This research not only discovers a variety of exceptional UV NLO crystals but also provides a feasible method to increase the likelihood of finding polar materials.

Elucidation of the Transport Properties of Calcium-Doped High Entropy Rare Earth Aluminates for Solid Oxide Fuel Cell Applications.

Solid oxide fuel cells (SOFCs) are paving the way to clean energy conversion, relying on efficient oxygen-ion conductors with high ionic conductivity coupled with a negligible electronic contribution. Doped rare earth aluminates are promising candidates for SOFC electrolytes due to their high ionic conductivity. However, they often suffer from p-type electronic conductivity at operating temperatures above 500°C under oxidizing conditions caused by the incorporation of oxygen into the lattice. High entropy materials are a new class of materials conceptualized to be stable at higher temperatures due to their high configurational entropy. Introducing this concept to rare earth aluminates can be a promising approach to stabilize the lattice by shifting the stoichiometric point of the oxides to higher oxygen activities, and thereby, reducing the p-type electronic conductivity in the relevant oxygen partial pressure range. In this study, the high entropy oxide (Gd,La,Nd,Pr,Sm)AlO3 is synthesized and doped with Ca. The Ca-doped (Gd,La,Nd,Pr,Sm)AlO3 compounds exhibit a higher ionic conductivity than most of the corresponding Ca-doped rare earth aluminates accompanied by a reduction of the p-type electronic conductivity contribution typically observed under oxidizing conditions. In light of these findings, this study introduces high entropy aluminates as a promising candidate for SOFC electrolytes.

High-Entropy Strategy for Improved Mechanical and Energy Storage Properties in BaTiO3-BiFeO3-Based Ceramics.

Dielectric capacitors are employed extensively due to their exceptional performance, including a rapid charge-discharge speed and superior power density. However, their practical implementation is hindered by constraints in energy-storage density (ESD), efficiency (ESE), and thermal stability. To achieve domain engineering and improved relaxor behavior in 0.67BiFeO3-0.33BaTiO3-based Pb-free ceramics, the concerns have been addressed here by employing a synergistic high-entropy strategy involving the design of the composition of Sr(Mg1/6Zn1/6Ta1/3Nb1/3)O3 with B-site multielement coexistence and high configuration entropy. Remarkably, in (0.67-x)BiFeO3-0.33BaTiO3-xSr(Mg1/6Zn1/6Ta1/3Nb1/3)O3 ceramics with x = 0.08, a good ESE (η) of 75% and a recoverable ESD (Wrec) of 2.4 J/cm3 at 190 kV/cm were attained together with an ultrahigh hardness of ∼7.2 GPa. The high-entropy strategy, which is tailored by an increase in configuration entropy, can be attributed to the superior mechanical and ES properties. It also explains the enhanced random field and relaxation behavior, the structural coexistence of ferroelectric rhombohedral (R3c) and nonpolar pseudocubic (Pm-3m) symmetries, the decreased domain size, and evenly distributed polar nanoregions (PNRs). Moreover, improved thermal stability and outstanding frequency stability are also obtained. By boosting the configuration entropy, BiFeO3-BaTiO3 materials dramatically improved their complete energy storage performance. This suggests that designing high-performance dielectrics with high entropy can be a convenient yet effective technique, leading to the development of advanced capacitors.

Designing lithium halide solid electrolytes

All-solid-state lithium batteries have attracted widespread attention for next-generation energy storage, potentially providing enhanced safety and cycling stability. The performance of such batteries relies on solid electrolyte materials; hence many structures/phases are being investigated with increasing compositional complexity. Among the various solid electrolytes, lithium halides show promising ionic conductivity and cathode compatibility, however, there are no effective guidelines when moving toward complex compositions that go beyond ab-initio modeling. Here, we show that ionic potential, the ratio of charge number and ion radius, can effectively capture the key interactions within halide materials, making it possible to guide the design of the representative crystal structures. This is demonstrated by the preparation of a family of complex layered halides that combine an enhanced conductivity with a favorable isometric morphology, induced by the high configurational entropy. This work provides insights into the characteristics of complex halide phases and presents a methodology for designing solid materials.

An entropy engineering strategy to design sulfur-resistant catalysts for dry reforming of methane

The real-world conditions for dry reforming of methane (DRM) inevitably involve the presence of sulfur-containing compounds. Therefore, a general principle for designing sulfur-resistant catalysts is highly desired for the DRM process. In this work, driven by lower Gibbs free energy via entropy engineering, the high-entropy NiAl2O4-type catalyst {(Ni3MoCoZn)Al15Ox} is synthesized by a mechanochemical ball milling process. The DRM performance of the high-entropy catalyst was tested before and after being sulfided by SO2, and compared with those of the control catalysts. Various techniques such as XPS, HAADF-STEM, SO2-TPD, TGA-DSC, FTIR, and DFT theoretical calculations are utilized to reveal the mechanism of sulfur resistance in the high-entropy catalyst. The results indicate that the formation of crystalline high-entropy oxides in the (Ni3MoCoZn)Al15Ox, with its relatively higher configurational entropy, protects itself from SO2 poisoning. This contributes to superior SO2 tolerance compared to the control (Ni3)Al18Ox, and thus offers better DRM stability than the control binary, ternary, or quaternary catalysts after pre-sulfurization. The key essence of sulfur resistance lies in the lower adsorption energy of SO2 on the high-entropy catalyst. This high-entropy stabilization towards an anti-sulfur strategy may inspire the design and development of sulfur-resistant catalysts for catalytic applications in the near future.

Ultrahigh Degree of Cationic Disorder, Configurational Entropy in New Type of High-Entropy Pseudobrookite Phase.

High-entropy ceramics exhibit various excellent properties owing to their high configurational entropy, which is caused by multi-principal elements sharing one lattice site. The configurational entropy will further increase significantly if multi-principal elements randomly share two different lattice sites. For this purpose, pseudobrookite phase containing two cationic lattice sites (A and B sites) is selected, and corresponding high-entropy pseudobrookite (M2+ 0.4M3+ 1.2)Ti1.4O5 is synthesized. Herein, the distribution of the 2-valent and 3-valent cations in the A and B sites are analysed in depth. The distance between the A and B sites in the crystal structure models which are constructed by the Rietveld analysis is calculated and defined as distance d. Meanwhile, the atomic column positions in the STEM images are quantified by a model-based mathematical algorithm, and the corresponding distance d are calculated. By comparing the distance d, it is determine that the 2-valent and 3-valent cations are jointly and disorderly distributed in the A and B sites in high-entropy (M2+ 0.4M3+ 1.2)Ti1.4O5. The density functional theory (DFT) simulations also demonstrate that this type of crystal structure is more thermodynamically stable. The higher degree of cationic disorder leads to a higher configurational entropy in high-entropy (M2+ 0.4M3+ 1.2)Ti1.4O5, and endows high-entropy (M2+ 0.4M3+ 1.2)Ti1.4O5 with very low thermal conductivity (1.187-1.249Wm-1K-1).

Thermoelectric properties of half-Heusler alloys

Half-Heusler alloys (HHs) as medium- and high-temperature thermoelectric materials have attracted increasing considerable attention, owing to their excellent mechanical properties and thermal stability. Nonetheless, the intercoupling between the Seebeck coefficient and electrical conductivity, and their high thermal conductivity limit the furthermore enhancement of their thermoelectric properties. This review systemically summarizes and analyses the various current strategies for improving thermoelectric properties, such as manipulating band structure, optimizing electron and phonon transports, and constructing high configurational entropy, etc. Moreover, the possible deficiencies of the existing electric-phonon transport mechanisms are highlighted and discussed, which aiming to provide a meaningful guide for future efforts to accelerate the development of HHs. Finally, based on current research, a new potential future for the integration of single crystal technology and high-entropy effect is introduced for HHs.

Elinvar-Like Effect Induced by High Lattice Distortion in Zr 6 Ta 2 O 17 Ceramics

Super strength and toughness, excellent deformation resistance, and high-temperature service performance are the key factors to determine the practical application of new thermal barrier coatings (TBCs). The limited mobility of dislocations and the internal inherent defects in ceramics will inevitably lead to the decline of strength–plasticity and the reduction of service performance. Introducing preexisting twin boundaries and stacking faults (SFs) or preparing ceramic materials with high configuration entropy has demonstrated to be an effective strategy for enhancing the mechanical properties of ceramics. However, due to the positive thermal expansion coefficient of most ceramics and the remarkable increase of structural disorder at elevated temperature, the problem of elastic softening has become a bottleneck restricting the high-temperature service life of new TBCs. In this paper, the deformation behavior of high configuration entropy Zr 6 Ta 2 O 17 ceramics at 25 to 1,200 °C was in situ monitored via digital image correlation technique and three-point bending test platform in high-temperature environment. A remarkable Elinvar-like effect appears in the Zr 6 Ta 2 O 17 ceramic. More interestingly, mechanical deformation dominates the severe lattice distortion (deformation twins, SFs) and the disorder–order transition of chemical order at the atomic scale, while temperature can further enhance the degree of lattice distortion and ordering of Zr 6 Ta 2 O 17 ceramics. Furthermore, the atomic fluctuations at high temperature promotes the comprehensive improvement of mechanical properties in the Zr 6 Ta 2 O 17 ceramics.

Generic synthesis of high-entropy phosphides for fast and stable Li-ion storage

High-entropy phosphides are first synthesized, achieving much faster charge transfer and greater anti-pulverization capability than the parent phases owing to the high configurational entropy.

Configuration-entropy effects on BiFeO3–BaTiO3 relaxor ferroelectric ceramics for high-density energy storage

A high-configuration entropy results in the formation of grain boundaries and nanoclusters, which act as barriers for enhancing breakdown strength and energy-storage capability.

MOF-Derived Trifunctional High Entropy Sulfides as an Electrocatalyst for Alkaline Unitized Regenerative Fuel Cell Application

Electrochemical devices such as electrolyzers (EL), fuel cells (FC), metal-air batteries (MAB), and unitized regenerative fuel cells (URFC) are key components in our drive toward a renewable energy-based power infrastructure. The potential scale of these devices requires the usage of catalytic materials that exhibit not only excellent catalytic activity but also commendable durability. Conventional precious metal catalysts such as Pt, Ir, Rh, Ru, and Pd are utilized for variable deployments during electrocatalysis. 1 Recent trends in alloying, tuning the band structure, nanosizing of particles, and application of earth-abundant transition metals, have immensely increased the economic feasibility and practical applications of a new genre of electrochemical devices. 2 Here, strategically designed materials, such as metal-organic frameworks (MOF), offers a new route for synthesizing the alloys and their derivatives with high porosities and excellent catalytic activity. 3 High entropy alloys (HEA) containing multiple (four or more) components of metallic oxides, sulfides, and phosphides have emerged as a new class of materials. Effects such as lattice distortion, entropy stabilization, cocktail effect, and formation of multiple oxidation states in such HEA enable access to multiple catalytic centers for catalyzing more than one small molecule activation reaction. 4 The current work focuses on the synthesis of FeCuCoMnNi-based high entropy sulfide (HES) via a unique MOF route. This HES material successfully demonstrates three distinct catalytic reactions: oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER). The surface morphology and phase of the HES can be critically curated via sulfurizing the multi-metal MOF precursor, which was monitored with a battery of surface characterization techniques. This HES displayed an impressive bifunctionality index of 0.80 V and 1.87 V for application in alkaline URFC (ORR/OER) and EL (HER/OER), where moderate to low overpotentials were observed for OER (η OER = 380 mV), ORR (η ORR = 420 mV), and HER (η HER = 260 mV). The superior electrochemical performance of this HES is attributed to the surface reconstruction mechanism upon the inclusion of transition metals such as Fe, Co, and Mn to Ni leading to the formation of the key Ni-OOH layer. Along with excellent performance, the HES exhibited good durability at +1.5 V vs. RHE up to 12 hours while retaining ~75% of the initial current density, indicating the presence of a high configurational entropy in the material. References Huynh, M., Ozel, T., Liu, C., Lau, E. C., & Nocera, D. G. 2017 Chemical science, 8(7), 4779-4794.Xu, J., Li, J., Xiong, D., Zhang, B., Liu, Y., Wu, K. H., ... & Liu, L. 2018 Chemical science, 9(14), 3470-3476.Karmakar, A., Kumar, N., Samanta, P., Desai, A. V., & Ghosh, S. K. 2016 Chemistry–A European Journal, 22(3), 864-868.Miracle, D. B., Miller, J. D., Senkov, O. N., Woodward, C., Uchic, M. D., & Tiley, J. 2014 Entropy, 16(1), 494-525 Figure 1

A Ni/Co-free high-entropy layered cathode with suppressed phase transition and near-zero strain for high-voltage sodium-ion batteries

High-entropy layered oxides have emerged as a new class of cathode materials for sodium-ion batteries by providing infinite possibilities to tailor energy storage capabilities. However, owing to the lack of advanced high-entropy layered material, the influence of configurational entropy/compositional disorder on the high-voltage electrochemical performance of sodium-based layered cathode has seldom been explored. In this work, a Ni/Co-free high-entropy layered oxide P2-Na0.65Mn0.65Cu0.2Li0.06Mg0.015Ti0.015Al0.015Zr0.015Y0.015La0.015O2 (Mn-Cu-HEO) was prepared by stirring hydrothermal method, and investigated as a new cathode material for sodium-ion batteries. It is found that high configurational entropy and strong M−O configurations (M = Ti, Al, Zr, Y, and La) greatly stabilize the layered framework structure and MnO6 octahedral local structure, restraining the deleterious phase transition and large volume change during high-voltage cycling, thus resulting in high reversible cationic/anionic redox. In the meantime, disordered atomic arrangement in transition metal layer efficaciously mitigates Na+/vacancy ordering during de-/sodiation, enhancing the Na+ transport kinetics. Benefiting from the high-entropy stabilization effect, complex atomic arrangement, and multielemental composition, Mn-Cu-HEO displays splendid cyclic stability (87.2 % capacity retention after 500 cycles, very small change in cell volume (0.53 %) after 100 cycles), excellent rate capability (55.5 mAh g−1 at 10C), and a usable reversible capacity of 85.1 mAh g−1 at 1C in high-voltage range of 2.0–4.5 V. This work expands the horizons of high-entropy layered materials, providing new insight in the design and construction of highly stable and high-voltage sodium ion host.

Unexpected spinodal decomposition in as-cast eutectic high entropy alloy Al30Co10Cr30Fe15Ni15

By integrating calculation of phase diagram (CALPHAD) simulations, ab initio molecular dynamics (AIMD) and experimental validation, we shed light on the unexpected spinodal decomposition in as-cast Al30Co10Cr30Fe15Ni15 alloy, as opposed to the eutectic BCC/B2 microstructure predicted by CALPHAD. We showed that the eutectic high entropy alloy (EHEA) and spinodal decomposition (SD) may be correlated with each other. A shift from as-cast EHEA to SD can be triggered by the strong short-range ordering in the EHEA liquid phase and high configuration entropy of the metastable phase. CALPHAD showed that the low eutectic temperature of Al30Co10Cr30Fe15Ni15 alloy is stabilized by the short-range and topological ordering (SRO), rendering a small undercooling ΔT for partitionless solidification of the metastable B2 phase. AIMD calculations showed that the particular metastable-like liquid preordering might reduce interface energy between the eutectic liquid and saturated B2, facilitating metastable saturated phase formation even with a small undercooling and suppressing the eutectic reaction. The single B2 phase might have solidified in the spinodal region of the phase diagram resulting in a shift from as-cast EHEA to SD. The interplay between SD and EHEAs presents an alternative route to explore spinodal HEAs by simple as-casted samples without lengthy heat treatments for homogenization.

High-Entropy Co-Free O3-Type Layered Oxyfluoride: A Promising Air-Stable Cathode for Sodium-Ion Batteries.

Sodium-ion batteries have recently emerged as a promising alternative to lithium-based batteries, driven by an ever-growing demand for electricity storage systems. The present workproposes a cobalt-free high-capacity cathode for sodium-ion batteries, synthesized using a high-entropy approach. The high-entropy approach entails mixing more than five elements in a single phase; hence, obtaining the desired properties is a challenge since this involves the interplay between different elements. Here, instead of oxide, oxyfluoride is chosen to suppress oxygen loss during long-term cycling. Supplement to this, lithium isintroduced in the composition to obtain high configurational entropy and sodium vacant sites, thus stabilizing the crystal structure, accelerating the kinetics of intercalation/deintercalation, and improving the air stability of the material. With the optimization of the cathode composition, a reversible capacity of 109mAhg-1 (2-4V) and 144mAhg-1 (2-4.3V) is observed in the first few cycles, along with a significant improvement in stability during prolonged cycling. Furthermore, in situ and ex situ diffraction studies during charging/discharging reveal that the high-entropy strategy successfully suppresses the complex phase transition. The impressive outcomes of the present work strongly motivate the pursuit of the high-entropy approach to develop efficient cathodes for sodium-ion batteries.