First-principles Density Functional Theory Research Articles

Superconductivity and high hardness in scandium-borides under pressure.

Exploration of new superconducting or superhard transition-metal borides has attracted extensive interest in the past few decades. In this study, we conducted comprehensive theoretical investigations in the scandium-boron binary system by employing a structural search method based upon first-principles density functional theory. Among the six predicted superconducting scandium-borides, ScB14 (Pm3̄) has the highest superconducting transition temperature Tc = 12.3 K and a Vickers hardness of 12.6 GPa at ambient pressure. The superconductor ScB4 (C2/m) has Tc = 3.6 K and a high Vickers hardness of 25.5 GPa at ambient pressure. Further analysis indicates that the previously synthesized ScB15 (P41) is of superhardness. Our discoveries not only enrich the phase diagram of scandium-borides, but also pave the way for future experimental validations and potential applications of superconducting scandium-borides in industry.

Impact of Pressure on Metavalent Bonding in BiTe influencing Electronic Topological Transitions.

BiTe, a member of the (Bi2)m(Bi2Te3)n homologous series, possesses natural van der Waals-like heterostructure with a Bi2 bilayer sandwiched between the two [Te-Bi-Te-Bi-Te] quintuple layers. BiTe exhibits both the quantum states of weak topological and topological crystalline insulators, making it a dual topological insulator and a suitable candidate for spintronics, quantum computing and thermoelectrics. Herein, we demonstrate that the chemical bonding in BiTe is to be metavalent, which plays a significant role in the pressure dependent change in the topology of the electronic structure Fermi surface. The enhancement of the metavalent bonding character with pressure in BiTe is evidenced from first-principles density functional theory (DFT) calculations. Due to the change in the Fermi surface topology, we have visualized electronic topological transitions (ETT) at 1 and 3 GPa through pressure dependent synchrotron X-ray diffraction analysis and Raman spectroscopy. The correlation between the metavalent bonding and ETT offers insights into chemical bonding influenced transitions in quantum materials.

Diffusion behavior of cesium in graphite matrix for a high-temperature reactor pebble-bed module: a first-principles study

ABSTRACT Graphite is one of the main materials of the fuel element in High Temperature Reactor Pebble-bed Module (HTR-PM). Knowledge of the behavior of Cesium (Cs) in graphite is necessary for reliable source term analysis under normal and accidental conditions for HTR-PMs. In this study, the diffusion behavior of Cs atoms in graphite was calculated to estimate the diffusivity of Cs using the first-principles density functional theory. The results show that the energy barriers for vacancy and interstitial diffusion are significantly different (2.257 eV and 0.051 eV, respectively), suggesting that interstitial diffusion is more likely to occur in high-temperature graphite. However, experimental data in literatures indicate that the activation energy for Cs diffusion in graphite falls between 1.5 to 3.3 eV, aligning with the migration energy for vacancy diffusion identified in this study. It is hypothesized that experimental observations of diffusion may be primarily influenced by vacancies. The results may help designers to select appropriate parameters or make physical assumptions and to consider the radiation risks caused by the residual fission product (Cs) in graphite.

Effect of the Ti2CT x (T x = O, OH, and H) Functionalization on the Formation of (TiO2)5/Ti2CT x Composites.

First-principles density functional theory calculations are carried out on the (TiO2)5 cluster supported on the Ti2CT x (0001) surface with different chemical terminations, i.e., -H, -O, and -OH, to study the interaction and understand the Ti2CT x functionalization effect on the formation of (TiO2)5/Ti2CT x composites. Results show an exothermic interaction for all cases, whose strength is driven by the surface termination, promoting weaker bonds when the MXene is functionalized with H atoms. For Ti2CH2 and Ti2C(OH)2 MXenes, the interaction is accompanied by a charge transfer towards the titania cluster. All adsorptions are accompanied by a significant structural deformation of the titania nanocluster. The analysis of the density of states of (TiO2)5/Ti2CH2 and (TiO2)5/Ti2C(OH)2 composites shows a clear almost metallic character with titania-related states close to the Fermi level. However, for (TiO2)5/Ti2CO2, the band positions are similar to those of a Type-I heterojunction. Overall, the MXene surface termination influence on the TiO2/MXene interaction is unveiled, providing more stable composite formations when the MXene surface is functionalized with -H and -OH groups, where the adsorption process is accompanied by significant charge transfer.

Janus graphene nanoribbons with localized states on a single zigzag edge.

Topological design of π electrons in zigzag-edged graphene nanoribbons (ZGNRs) leads to a wealth of magnetic quantum phenomena and exotic quantum phases1-10. Symmetric ZGNRs typically show antiferromagnetically coupled spin-ordered edge states1,2. Eliminating cross-edge magnetic coupling in ZGNRs not only enables the realization of a class of ferromagnetic quantum spin chains11, enabling the exploration of quantum spin physics and entanglement of multiple qubits in the one-dimensional limit3,12, but also establishes a long-sought-after carbon-based ferromagnetic transport channel, pivotal for ultimate scaling of GNR-based quantum electronics1-3,9,13. Here we report a general approach for designing and fabricating such ferromagnetic GNRs in the form of Janus GNRs (JGNRs) with two distinct edge configurations. Guided by Lieb's theorem and topological classification theory14-16, we devised two JGNRs by asymmetrically introducing a topological defect array of benzene motifs to one zigzag edge, while keeping the opposing zigzag edge unchanged. This breaks the structural symmetry and creates a sublattice imbalance within each unit cell, initiating a spin-symmetry breaking. Three Z-shaped precursors are designed to fabricate one parent ZGNR and two JGNRs with an optimal lattice spacing of the defect array for a complete quench of the magnetic edge states at the 'defective' edge. Characterization by scanning probe microscopy and spectroscopy and first-principles density functional theory confirms the successful fabrication of JGNRs with a ferromagnetic ground-state localized along the pristine zigzag edge.

First-principles investigations of As-doped tetragonal boron nitride nanosheets for toxic gas sensing applications.

Pristine and arsenic-doped tetragonal boron nitride nanosheets (BNNS and As-BNNS) have been reported as potential candidates for toxic gas sensing applications. We have investigated the adsorption behavior of BNNS and As-BNNS for CO2, H2S, and SO3 gas molecules using first-principles density functional theory (DFT). Both BNNS and As-BNNS possess negative cohesive energies of -8.47 and -8.22 eV, respectively, which indicates that both sheets are energetically stable. Successful adsorption is inferred from the negative adsorption energy and structural deformation in the vicinity of the adsorbent and adsorbate. As-doping results in a significant increase in adsorption energies from -0.094, -0.175, and -0.462 eV to -2.748, -2.637, and 3.057 eV for CO2, H2S and SO3 gases, respectively. Due to gas adsorption, the electronic bandgap in As-BNNS varies by approximately 32% compared to a maximum of 24% in BNNS. A notable fluctuation in the energy gap and electrical conductivity is seen, with ambient temperature being the point of maximal sensitivity. For SO3, the maximum charge transfer during adsorption in BNNS and As-BNNS is determined to be 0.08|e| and 0.25|e|, respectively. Due to the interaction with gases, all structures exhibit an extremely high absorption coefficient on the order of 104 cm-1 with minimal peak shifting. Additionally, doping an As atom on BNNS' surface remarkably improved its ability to sense CO2, H2S, and SO3 gasses.

Tuning anomalous Hall conductivity via antiferromagnetic configurations in GdPtBi.

The magnetic, electronic, and topological properties of GdPtBi were systematically investigated using first-principles density functional theory (DFT) calculations. Various magnetic configurations were examined, including ferromagnetic (FM) and antiferromagnetic (AFM) states, with particular focus on AFM states where the Gd magnetic moments align either parallel (AFM‖) or perpendicular (AFM⊥) to the [111] crystal direction. For AFM⊥, the in-plane angles ϕ were varied at ϕ = 0°, 15°, and 30° (denoted as AFM⊥,ϕ=0°, AFM⊥,ϕ=15°, and AFM⊥,ϕ=30°, respectively). The ground-state magnetic structure of GdPtBi was validated through dipolar magnetic field calculations at the muon sites, corroborating the internal magnetic fields observed in muon spin relaxation (μSR) experiments. The results indicate that the AFM⊥,ϕ=30° configuration aligns with the μSR-measured internal field. The DFT-calculated band structure and Berry curvature reveal that AFM⊥ belongs to the triple-point semimetals (TPSMs) where the triple-point nodes positioned along the Z-Γ-Z and F-Γ-F paths have energies that shift as the spin-orbit coupling strength varies with ϕ. Notably, this shift in triple-point energy corresponds to a significant change in the anomalous Hall conductivity (AHC, σxy), with a difference of 75.06 Ω-1 cm-1 at the Fermi energy between AFM⊥,ϕ=0° and AFM⊥,ϕ=30°. These findings highlight the potential for controlling the AHC through precise manipulation of the AFM structure.

First-principles study of CO2 and H2O adsorption on the anatase TiO2(101) surface: effect of Au doping.

Photocatalytic reduction of CO2 will play a major role in future energy and environmental crisis. To investigate the adsorption mechanisms of CO2 and H2O molecules involved in the catalytic process on the surface of anatase titanium dioxide 101 (TiO2(101)) and the influence of Au atom doping on their adsorption, first-principles density functional theory calculations were used. The results show that 1. Au atom doping stabilizes the structure of the catalyst system and reduces the band gap, facilitating the reaction of CO2 and H2O molecules. 2. The O site is the most stable adsorption site for the CO2 molecule on the surface, and chemical adsorption occurs, leading to structural deformation during the adsorption process. The adsorption energy is the highest when the H2O molecule is adsorbed parallel to the surface, and there is a bonding trend between H2O and the surface. 3. The adsorption performances of CO2 and H2O molecules improve after Au atom doping. 4. Au atom doping creates stronger adsorption sites on the catalyst surface, with the two-coordinated O atoms near the Au atom becoming the preferred adsorption sites for both molecules. The revealed microscopic mechanism provides theoretical support for the design and manufacture of photocatalytic CO2 reduction catalysts.

Free Carrier Auger-Meitner Recombination in Monolayer Transition Metal Dichalcogenides.

Microscopic many-body models based on inputs from first-principles density functional theory are used to calculate the carrier losses due to free carrier Auger-Meitner recombination (AMR) processes in Mo- and W-based monolayer transition metal dichalcogenides as a function of the carrier density, temperature, and dielectric environment. Despite the exceptional strength of Coulomb interaction in the two-dimensional materials, the AMR losses are found to be similar in magnitude to those in conventional III-V-based quantum wells for the same wavelengths. Unlike the case in III-V materials, the losses show nontrivial density dependencies due to the fact that bandgap renormalizations on the order of hundreds of millielectronvolts can bring higher bands into or out of resonance with the optimal energy level for the AMR transition, approximately one bandgap from the lowest band. Similar nontrivial behaviors are found for the dependencies of AMR on the temperature and dielectric screening.

A favorable catalytic root for the reduction reaction of SOCl2 from the constructed CoPc/CuPc composite

Abstract CoPc, as a catalyst for lithium thionyl chloride (Li/SOCl2) battery, is generally recognized as having catalytic activity, and its catalytic activity can be further improved by compounding it on some substrates. In this paper, CoPc/CuPc with smaller particle size was synthesized by two-step method. It was found that when the product was constructed, not only a loose film could be formed on the surface of carbon cathode, but also a large number of holes could be formed inside it. In addition, the adsorption of SOCl2 by CoPc and CuPc and the surface electrostatic charge distribution was studied by the first-principles density functional theory calculations (DFT). Compared with the bare, the voltage of the battery using the CoPc/CuPc composites as catalyst increased by 0.25 V, and the discharge time was prolonged by 12 min. Observing the morphology after discharge, it can be found that there are many particles around 200 nm on the surface and a large number of particles around 50 nm inside.

Functional Group Effects on the Interfacial Adsorption of Arylquinoline-3-Carbonitriles on Iron: A DFT-D3 Investigation of Surface Interaction Mechanisms.

Reliable corrosion inhibition systems are crucial for extending the lifespan of industrial metal structures. Quinolines, with their high adsorption capacity and protective efficiency, are promising next-generation inhibitors. However, the impact of substitutions on their coordination with iron surfaces requires deeper understanding. Herein, we investigate the influence of various functional groups on the adsorption behavior of three 2-amino-4-arylquinoline-3-carbonitriles (AACs) on iron surfaces using first-principles density functional theory calculations. Results reveal that nitrophenyl and hydroxyphenyl significantly enhance the adsorption strength of AACs on the Fe(110) surface, facilitated by donor-acceptor interactions. Neutral molecules were more stable than their protonated counterparts. Key results show strong adsorption energies, with values ranging from -2.005 to -1.809 eV for the AACs, along with significant electron gains across carbon atoms as indicated by Bader charge analysis. These strong interactions result in notable charge redistribution and bond formation, as shown by projected density of states and electron density difference iso-surfaces. Furthermore, electron localization function analysis indicates that van der Waals interactions, influenced by multiple nitrogen atoms, play a crucial role in stabilizing the adsorbed molecules. Stronger adsorption through electron donation and retro-donation mechanisms suggests enhanced corrosion protection efficiency of these substituted quinolines. The conductor-like screening model for real solvents analysis provides complementary insights into the solvation characteristics. Overall, the findings demonstrate the specific role functional groups play in the coordination of arylquinoline-3-carbonitriles with iron surfaces.

Convergence Analysis and Predictions for Optimizing Reciprocal Grids: A First-Principles and Machine Learning Study.

When crystalline materials are investigated by performing first-principles density functional theory (DFT) calculations, the reciprocal grid should be fine enough to obtain the converged total energy and electronic structure. Herein, we performed a convergence test of the total energy for the density of reciprocal points to determine fine enough reciprocal grids for high-throughput calculations. Our results show that the nonlinearity of the band structures affects the convergence of the total energy, especially for materials with a finite band gap. We further investigate which physical properties make a finer reciprocal grid necessary based on machine learning (ML) analysis. Our developed models using DFT-based features and elemental properties-based features exhibit R2 of 0.803 and 0.880, respectively. Our ML model quantitatively shows the importance of nonlinearity and band gaps in predicting errors in total energy calculations. Furthermore, our ML model using elemental features can be applied to estimate the appropriate reciprocal grid, facilitating high-throughput calculations.

Calcium-atom-modified boron phosphide (BP) biphenylene as an efficient hydrogen storage material.

Porous nanosheets have attracted significant attention as viable options for energy storage materials because of their exceptionally large specific surface areas. A recent study (Int. J. Hydrogen Energy, 2024, 66, 33-39) has demonstrated that Li/Na-metalized inorganic BP-biphenylene (b-B3P3) and graphenylene (g-B6P6) analogues possess suitable functionalities for hydrogen (H2) storage. Herein, we evaluate the H2 storage performance of alkaline earth metal (AEM = Be, Mg, Ca)-decorated b-B3P3 and g-B6P6 structures based on first-principles density functional theory (DFT) calculations. Our investigations revealed that individual Be and Mg atoms are not stable on pure b-B3P3 and g-B6P6 sheets, and the formation of aggregates is favored due to their low binding energy to these surfaces. However, the binding energy improves for Ca-decorated b-B3P3 (b-B3P3(mCa)) and g-B6P6 (g-B6P6(nCa)) structures, forming stable and uniform mCa(nCa) (m and n stand for the numbers of Ca atom) coverages on both sides. Under maximum hydrogenation, the b-B3P3(8Ca) and g-B6P6(16Ca) structures exhibited the ability to adsorb up to 32H2 and 48H2 molecules with average adsorption energy (E a) values of -0.23 eV per H2 and -0.25 eV per H2, respectively. Gravimetric H2 uptakes of 7.28 wt% and 5.56 wt% were found for b-B3P3(8Ca)@32H2 and g-B6P6(16Ca)@48H2 systems, exceeding the target of 5.50 wt% set by the US Department of Energy (DOE) to be reached by 2025. Our findings indicate the importance of these b-B3P3 and g-B6P6 sheets for H2 storage technologies.

Balancing Activity and Selectivity in Two-Electron Oxygen Reduction through First Coordination Shell Engineering in Cobalt Single Atom Catalysts.

The electrochemical two-electron oxygen reduction reaction (2e- ORR) offers a potentially cost-effective and eco-friendly route for the production of hydrogen peroxide (H2O2). However, the competing 4e- ORR that converts oxygen to water limits the selectivity towards hydrogen peroxide. Accordingly, achieving highly selective H2O2 production under low voltage conditions remains challenging. Herein, guided by first-principles density functional theory (DFT) calculations, we show that modulation the first coordination sphere in Co single atom catalysts (Co-N-C catalysts with Co-NxO4-x sites), specifically the replacement of Co-N bonds with Co-O bonds, can weaken the *OOH adsorption strength to boost the selectivity towards H2O2 (albeit with a slight decrease in ORR activity). Further, by synthesizing a series of N-doped carbon-supported catalysts with Co-NxO4-x active sites, we were able to validate the DFT findings and explore the trade-off between catalytic activity and selectivity for 2e- ORR. A catalyst with trans-Co-N2O2 sites exhibited excellent catalytic activity and H2O2 selectivity, affording a H2O2 production rate of 12.86 and an half-cell energy-efficiency of 0.07 during a 100-hours H2O2 production test in a flow-cell.

Role of solute elements in Mg-Mg2Ni hydrogen storage alloys: A first-principles calculation study

The effects of various alloying elements on the performance of Mg-Mg2Ni hydrogen storage alloys were investigated by performing first-principles density functional theory calculations. We examined the important characteristics of hydrogen storage alloys by considering both Mg-based solid solution and Mg2Ni-based intermetallic compound phases, where the hydride forms are MgH2 and Mg2NiH4, respectively. In particular, qualitatively valid information for predicting changes in plateau pressures in the pressure-composition-temperature (PCT) curve was provided by calculating changes in the energy of related hydrogenation reactions. The effects of alloying elements on volume changes due to hydrogenation reactions were also obtained to provide additional criteria for the practical use of hydrogen storage alloys. For the Mg2Ni-based intermetallic compound, we examined the site preference of each alloying element, considering the designated stoichiometry of the base alloy. Based on the revealed site preferences, the effects of various possible alloying elements on the properties of Mg2Ni-based hydrides were also examined. Electronic structure analyses were further conducted to elucidate the detailed mechanisms underlying the role of the additional solute elements.

3D Heisenberg universality in the van der Waals antiferromagnet NiPS3

Van der Waals (vdW) magnetic materials are comprised of layers of atomically thin sheets, making them ideal platforms for studying magnetism at the two-dimensional (2D) limit. These materials are at the center of a host of novel types of experiments, however, there are notably few pathways to directly probe their magnetic structure. We confirm the magnetic order within a single crystal of NiPS3 and show it can be accessed with resonant elastic X-ray diffraction along the edge of the vdW planes in a carefully grown crystal by detecting structurally forbidden resonant magnetic X-ray scattering. We find the magnetic order parameter has a critical exponent of β ~ 0.36, indicating that the magnetism of these vdW crystals is more adequately characterized by the three-dimensional (3D) Heisenberg universality class. We verify these findings with first-principles density functional theory, Monte-Carlo simulations, and density matrix renormalization group calculations.

Momentum-Direct Infrared Interlayer Exciton and Photodetection in Multilayer van der Waals Heterostructures.

Interlayer excitons (IX), spatially separated electron-hole pair quasiparticles, can form in type-II van der Waals heterostructures (vdWH). To date, the most widely studied IX in hetero- and homobilayer transition metal dichalcogenides feature momentum-indirect and visible interlayer recombinations. However, momentum-direct IX emissions and interlayer absorptions, especially in the infrared, are crucial for excitonic devices but remain underexplored. In this work, we propose and construct a multilayer WSe2/InSe vdWH that hosts momentum-direct IX and manifests near-infrared interlayer absorptions at room temperature, verified by first-principles density functional theory calculations. We conduct power- and temperature-dependent photoluminescence spectroscopies and extract the IX binding energy to be 43 ± 5 meV. Furthermore, we manipulate the IX emission electrically via the Stark effect and tune its energy by 180 meV. Taking advantage of the direct interlayer absorption, we fabricate a near-infrared vdWH photodetector modulated by strong photogating effect, and achieve the optimal photoresponsivity, specific detectivity, and response time of 33 A W-1, 1.8 × 1010 Jones, and 3.7 μs at 1150 nm. In addition, we test the imaging capability of the photodetector by integrating it into a single-pixel imaging system. Our work showcases the possibility for constructing infrared-responsive vdWH that hosts momentum-direct IX for future excitonic devices of optoelectronic applications.

Insights on formation of oxide layers, corrosion, and hydrogen embrittlement on the Ti2AlNb (1 1 0) surface: Density functional theory study

Ti2AlNb alloys offer good mechanical qualities and promise for use in various applications, such as aero-engines and other industries. However, corrosion and hydrogen embrittlement remain important concerns and limitations for their use. In this work, first-principle density functional theory is used to investigate the adsorption of hydrogen, fluorine and oxygen on the surface of Ti2AlNb (110). The effects of the considered adsorbates on the surface were compared by analysing the adsorption energy, charge density differences, density of states, and work function. The current findings revealed that the adsorption behaviour of all the adsorbates is exothermic and spontaneous due to the negative adsorption energy. More importantly, the effect of Van der Waals forces and dispersion correction was considered, it was found that for all adsorbates the dispersion correction approach exhibited the most stable adsorption energies (EadsDFT-D) than the standard density functional theory (EadsDFT). Thus, the standard DFT underestimates the adsorption energy. Furthermore, it was shown that the adsorption energy strength is dependent on the surface adsorption site, with the Ti-Nb and Al-Nb bridge sites being the most preferred sites for hydrogen, fluorine and oxygen adsorption. Subsequently, it was discovered that oxygen adsorption on the surface of Ti2AlNb (110) was more thermodynamically stable than hydrogen and fluorine. This suggests that the Ti2AlNb surface will likely suffer from oxidation rather than corrosion and hydrogen embrittlement. In addition, surface atoms showed electron-charge depletion, while adsorbates showed charge accumulation. The adsorption caused charge density redistribution and altered the surface work function.

Photocatalytic properties of two-dimensional CdO/ZrS2 heterojunctions:A first-principles study

Two-dimensional van der Waals heterojunctions are crucial for photocatalytic water splitting due to their unique properties. This study utilizes first-principles density functional theory to construct and analyze the CdO/ZrS₂ heterojunction. The results indicate that the heterojunction with an indirect band gap is structurally stable and exhibits excellent optical absorption, particularly in the ultraviolet and visible regions. Charge redistribution at the heterojunction interface enhances carrier separation, facilitating efficient photocatalytic reactions. Furthermore, applying strain modifies the bandgap, enhancing photocatalytic efficiency. Thus, the CdO/ZrS₂ heterojunction emerges as a promising candidate for high-efficiency photocatalysis.

A Liquid-Phase-Synthesized Cathode Composite with a Three-Dimensional Ion/Electron-Conducting Structure for All-Solid-State Lithium–Sulfur Batteries

All-solid-state lithium–sulfur batteries (ASSLSBs) with solid electrolytes (SEs) are considered promising next-generation energy storage systems owing to their high theoretical specific capacity (S: 1675 mAh g−1, Li2S: 1166 mAh g−1), high energy density (2500 Wh kg−1), non-flammability, and the natural abundance and low toxicity of sulfur.1 Moreover, the shuttle effect caused by the dissolution and diffusion of lithium polysulfide intermediates (Li2S x , 4 < x < 8) in liquid electrolytes is radically suppressed in solid-state redox reactions.2 However, three issues prevent ASSLSBs from efficiently utilizing active materials, resulting in low electrochemical performances: (1) the insulating property of Li2S/S towards both electrons and ions, (2) the severe stress and strain caused by the volumetric change (80%) of the sulfur cathode during lithiation/delithiation, and (3) the poor solid/solid interfacial contact between active material and SE. Therefore, the development of a solid-state cathode composite that can simultaneously overcome these three drawbacks is vital.Typically, a cathode composite of an ASSLSB comprises an SE, active material (S or Li2S), and conductive additives. The following strategies based on previous studies are key to realizing an optimal Li2S-based cathode composite: (1) reducing the particle size of the cathode SE (<1 μm),3 (2) enhancing the mixed (ion/electron) conductivity,4 and (3) constructing a stable cathode framework and 3D conductive pathways.5 However, approaches that can concurrently achieve all three requirements have rarely been reported. Additionally, alternatives to the commonly used mechanical mixing method, which can lead to poor interfacial contact and disintegration of the cathode structure, must be established.Herein, we report a Li2S-based cathode composite (AM–CR10/SE-liq/VGCF, or ACSV) with high mixed-conductivity and stability, fabricated by infiltrating a Li2S–LiI active material (AM) solution to a mesoporous carbon replica with ~10-nm-sized pores (CR10), followed by mixing the AM–CR10 composite with a liquid-phase-synthesized Li6PS5Br solid electrolyte (SE-liq) and vapor-grown carbon fibers (VGCFs) (Fig. 1(a)).The Rietveld analysis of the X-ray diffraction (XRD) patterns of liquid-phase-synthesized xLi2S-LiI (x = 1, 3, 5) indicated the possibility that part of the I− anions were incorporated into the Li2S lattice. First-principles density functional theory (DFT) calculation and Arrhenius plots measurement for 3Li2S-LiI (AM) revealed that the I− incorporation not only enhanced the ionic/electronic conductivities of Li2S but also promoted the Li2S/S conversion redox kinetics. The results of N2 adsorption/desorption testing for AM-CR10 based on Brunauer-Emmett-Teller (BET) and Barret-Joyner-Halenda (BJH) analysis ensured that the porous CR10 with mechanical reinforcement was filled with AM sufficiently without destruction, which can largely alleviate the volume expansion. Additionally, the XRD patterns and Raman spectra of the Li6PS5Br solid electrolyte (SE-liq) indicated that argyrodite-type Li6PS5Br was successfully obtained. The ionic conductivity of SE-liq determined by alternating current electrochemical impedance spectroscopy (EIS) was 2.22 mS·cm-1, which is comparable to that of Li6PS5Br (SE-bm) synthesized by the conventional ball milling method (2.26 mS·cm-1). Moreover, the field emission scanning electron microscope (FE-SEM) images and particle size analysis clarified that the particle size distribution of SE-liq was 0.1-1 μm and much smaller than that of SE-bm (1-30 μm). The high-resolution SEM images of the cathode composite ACSV suggested the presence of three-dimensional conductive pathways (Fig. 1(b)), while the conductivity measurements ensured that ACSV possessed a mixed ionic/electronic conductive behavior. In the charge/discharge profile of ACSV at a current density of 0.05 C at room temperature, the initial discharge capacity was 841.0 mAh·g−1. The discharge capacity increased to 1009.2 mAh·g−1 at the 20th cycle after activation, reaching 86.6% of the theoretical capacity of the Li2S material (1166 mAh·g-1) (Fig. 1(d)). Furthermore, the discharge capacity retention rate up to 100 cycles at a current density of 0.1C was 82.8%, while the Coulombic efficiency remained approximately 100% (Fig. 1(c)).In conclusion, the ASSLSB with this ACSV composite cathode exhibited exceptional capacity and reversibility, resulting from its mechanically sturdy configuration, high lithium storage capability, and three-dimensional mixed conductive structure. This study affirmed the potency of designing a Li2S-based composite cathode using liquid-phase methods to mitigate the insulating property of Li2S, inhibit the volumetric change within the cathode, and improve the solid/solid interfacial contact between Li2S and SE, thereby helping achieve high-performance ASSLSBs.