Transition metal vanadates (TMVs), have emerged as promising candidates due to their multiple redox reactions and high theoretical capacities. However, their practical application is hindered by poor electronic conductivity, large volume changes during lithiation, and rapid structural degradation. In this work, a series of bimetallic iron-cobalt vanadates, FexCo3-xV3O8 (x = 0, 1.5, 3), were synthesized through a facile hydrothermal process followed by thermal sintering under a controlled reducing atmosphere (N2/H2). The structural, morphological, and electrochemical properties of Co3V3O8 (CVO550), Fe3V3O8 (FVO550), and Fe1.5Co1.5V3O8 (FCVO550) were systematically investigated. X-ray diffraction and Rietveld refinement confirmed that all samples crystallize in a cubic spinel structure (Fd3m), with lattice parameters following Vegard's law, indicating successful solid-solution formation. The optimized FCVO550 sample exhibits a mesoporous architecture with a specific surface area of 21.38 m2 g-1, which enhances electrolyte penetration and buffers volume expansion during cycling. As a result, FCVO550 delivers a high reversible capacity of 893 mAh g-1 after 100 cycles at 0.2 A g-1. It maintains excellent rate capability (446 mAh g-1 at 5 A g-1). Electrochemical impedance spectroscopy reveals improved electronic conductivity and Li+ diffusion (DLi+ approximate to 2.98 & times; 10-11 cm2 s-1) due to the synergistic interaction between Fe and Co. Simulation results show FCVO minimizes volume expansion and strengthens TM-O hybridization. These results demonstrate that bimetallic vanadate engineering is an effective strategy for developing high-performance anodes for next-generation lithium-ion batteries.

Prelithiation of silicon (Si)-based anodes is an effective strategy to overcome low initial Coulombic efficiency (ICE), yet achieving a stable and scalable approach remains challenging. While prelithiation of SiOx anodes has been extensively explored, studies on Si anodes remain relatively limited. Herein, a facile and cost-effective solid-state thermal prelithiation method is developed. First, systematic calcination temperature optimization is conducted to evaluate its effects on lithium silicate phase formation and the resulting electrochemical performance. Controlled thermal reactions with LiOH at 900 degrees C enables the formation of optimally balanced lithium silicate phases on Si, enhancing Li+ transport and interfacial stability. Second, the influence of precursor chemistry is investigated by comparing LiOH and Li2CO3. Due to its higher reactivity, LiOH promotes a greater degree of prelithiation and more favorable lithium silicate phase formation, resulting in superior Li+ transport. In contrast, Li2CO3 contributes to improved electrode cycling stability through the formation of a more stable interphase. The optimized Si-LiOH electrode achieves a high ICE of similar to 90%, excellent rate capability (1140 mAh g(-1) at 5 A g(-1)), and extended cycle life compared to the pristine Si anode. The developed prelithiation strategy is a practical and scalable approach for next-generation high-capacity Si anodes of lithium-ion batteries.

Background Sodium-ion batteries (SIBs) are an intriguing secondary alternative source to switch over the prevalent lithium-ion batteries. The characteristics of global affordability and dissemination make them more familiar as sustainable storage. To confront the challenges posed by inadequate lithium resources, sodium has emanated as a substantial importance and is intended for vast electrochemical applications. Sodium-rich layered oxides are a fascinating candidate. Methods A Cu2+introduced cathode material NaxCu0.2Fe0.4Mn0.4O2 (Nax-CFM) composition with different sodium content were synthesized via a solid-state reaction. The sodium storage properties of as-synthesized Nax-CFM with varying sodium content were analyzed. In-situ XRD measurement of composition-optimized Nax-CFM was examined to evaluate the apparent structural changes during the charge-discharge process. Significant findings The synthesized Nax-CFM cathode exhibits a uniform morphology. The constant Cu2+ integration enhances sodium ion intercalation/de-intercalation kinetics and suppresses the formation of Mn3+ions. Furthermore, altered Na composition and cationic substitution induce better redox activity and endorse an efficient tactic to boost the electrochemical performance of the biphase (P2/O3) cathodes.

Orthopedic and dental implants must withstand mechanical loads while achieving stable bone-implant osseointegration. However, although titanium alloys are widely used due to their excellent mechanical properties and biocompatibility, their bioinert surfaces often limit bone bonding, indicating the need for effective surface modification strategies. Graphene oxide (GO) and reduced graphene oxide (rGO) have therefore attracted attention as tunable and bioactive surface modifiers. Here, “functional group-tunable GO” refers to tuning the abundance/type of oxygenated functional groups and the extent of sp2 restoration via hydrothermal reduction, thereby tailoring the surface chemistry of GO-based coatings. This tunability enables correlating reduction-driven functional group evolution with surface properties and biological responses, providing a rational route to optimize the rGO-coated Ti biointerface. This study investigated how hydrothermal reduction of GO modulates the structural, physicochemical, and biological performance of GO-based coatings on titanium substrates. GO was reduced at controlled temperatures (120–180 °C) to produce rGO with progressive graphitic restoration and functional group evolution, as confirmed by XRD, Raman spectroscopy, FTIR, and XPS analyses. rGO prepared at 160 °C exhibited the highest degree of structural recovery, characterized by enhanced sp2 conjugation and reduced oxygen content. GO- and rGO-coated titanium substrates were fabricated by spin coating and evaluated biologically. In vitro results showed that GO-coated Ti exhibited the lowest cell viability, whereas rGO-coated Ti prepared at 160 °C significantly enhanced cell proliferation and early osteogenic activity. In vivo evaluation using a rat distal femur lateral cortical miniscrew model further confirmed improved interfacial stability of rGO-coated Ti implants, as evidenced by a 45.8% increase in pull-out stiffness and a 51% increase in bone-implant contact during mid-to-late healing stages. These findings demonstrated that hydrothermal reduction effectively tunes the degree of reduction of graphene oxide and identifies rGO prepared at 160 °C as a promising surface engineering strategy for orthopedic and dental titanium implants.

In this study, we proposed a Li3InCl6 (LIC)/vapor-grown carbon fiber (VGCF) composite coating on single-crystalline LiNi0.6Co0.1Mn0.3O2 (SC-NCM613) via a two-step liquid-phase process, targeting simultaneous enhancement of ionic and electronic transport at the cathode-electrolyte interface. X-ray diffraction (XRD), Rietveld refinement, high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS) and Ni K-edge X-ray absorption spectroscopy (XAS) confirmed the formation of a uniform rock-salt-type LIC shell intimately connected with a 2 wt% VGCF network coating on SC-NCM613. This hybrid coating not only provided both the electronic/ionic transport network but also effectively suppressed H2 -> H3 tetrahedral distortions of SC-NCM613 and its irreversible surface oxygen loss during cycling. Under 0.1C cycling at 55 degrees C between 2.7 V and 4.3 V, the optimally loaded NCM@2VGCF@30LIC electrode retained 80.9% of its initial capacity after 50 cycles, with a coulombic efficiency exceeding 99% and minimal voltage polarization (Delta V = 0.056 V). These findings demonstrated that LIC/VGCF composite coatings represent a promising strategy to stabilize high-voltage NCM cathodes in sulfide-based all-solid-state batteries.

Sulfide-based solid electrolytes have attracted significant attention for all-solid-state batteries due to their high ionic conductivity. However, their practical application is limited by interfacial instability at the sodium metal anode, leading to side reactions that form Na2S and Na3Sb, and by structural defects such as voids and cracks that create electronic leakage pathways. To address these issues, a composite electrolyte was developed by incorporating Na3Zr2Si2PO12 (NZSP), a stable NASICON-type oxide, into Na3SbS4 (NSS). The optimized 90-10 wt.% NSS-NZSP composite improves microstructural integrity by filling voids and mitigating crack formation, enabling efficient Na+ transport. As a result, the ionic conductivity increases from 3.7 × 10-4 to 3.97 × 10-4 S cm-1, while the activation energy decreases from 0.25 to 0.22 eV. A half-cell configuration (Na2/3Fe1/2Mn1/2O2|90-10 wt.% electrolyte|Na) demonstrates stable cycling over 100 cycles at 0.05 A g-1, delivering a discharge capacity of 118.9 mAh g-1 at room temperature.

Background: Due to the limited resources, high costs, and safety risks associated with lithium-ion batteries (LIBs), sodium-ion batteries (SIBs) have emerged as one of the most promising alternatives for next-generation battery technologies owing to abundance and low cost of raw materials, sustainability and resource security, safety, comparable electrochemistry and wider temperature tolerance. Methods: To harness the advantages of both structural stability and capacity, we design a Cu/Fe co-doped P2/O3 biphasic layered cathode material, where the phase ratio is controlled by sintering temperature to achieve a tunable combination of O3 and P2 phases by different sintering temperature. Significant findings: Systematic investigations on the influence of different P2/O3 phase ratios on electrochemical performance reveal that the sample sintered at 900 degrees C exhibits higher reversible capacity and excellent capacity retention after long-term cycling at 1C rate. In addition, the reduced content of Jahn-Teller active Mn3+ ions in this sample contributes to enhanced structural stability and electrochemical performance. This work demonstrates that the synergistic effect of the biphasic structure effectively combines the advantages of both phases, resulting in cathode material for SIBs with high stability and capacity, thereby advancing the commercialization prospects of energy storage technologies.

In this work, we investigate the transition metal oxide spinel Fe3V3O8 using combined X-ray and neutron powder diffraction techniques to elucidate its crystal and magnetic structures. The results indicate that the compound retains a tetragonal crystal structure with space group I41/amd throughout the temperature range from 3.3 K to 475 K. The magnetic structure is described by the magnetic space group I41'/am'd, and no structural or magnetic phase transition is observed within this temperature window. At low temperatures, the system exhibits a canted antiferromagnetic ordering. Magnetization measurements reveal anomalies near 30 K and 100 K, corresponding to the μy component exceeding μz and reaching its maximum value, respectively. A pronounced magnetic hysteresis associated with magnetic domain formation is observed at 2 K, which becomes significantly suppressed above 300 K. Specific-heat measurements reveal a weak and broad anomaly around 180 K, likely associated with spin-glass-like behavior.

The development of cost-effective and sustainable sodium-ion batteries (SIBs) requires optimized hard carbon (HC) anodes. This study investigates honeycomb-like porous carbons derived from black soldier fly (BSF) frass, an abundant biomass waste, calcinated from 800 degrees C to 1400 degrees C. Among the samples, BSF-1200 exhibited the best electrochemical performance. Structural characterization (SEM, HRTEM) showed that BSF-1200 possesses a highly porous, sponge-like architecture that enhances electrolyte penetration and ion transport. Electrochemical tests revealed that BSF-1200 delivers a reversible capacity of 215.1 mAh g- 1 after 200 cycles at 0.2 A g- 1, along with an initial Coulombic efficiency of 68.26 %, low charge-transfer resistance, a high Na+ diffusion coefficient, and excellent rate capability. These improvements arise from its hierarchical porous structure, which facilitates efficient sodium storage. This work demonstrates a sustainable, low-cost approach for producing highperformance carbon anodes from insect-derived biomass. It offers valuable guidance for designing porous carbons for next-generation SIBs.

Vertically oriented graphene (VG) has been widely studied on silicon substrates, yet its potential for biomedical interface engineering remains underexplored. In this work, we demonstrate that VG grown by PECVD develops distinct temperature-dependent morphologies, ranging from dot-like nuclei at 500 degrees C to columnar structures at 640 degrees C and continuous sheet-like nanowalls at 700 degrees C. When directly deposited onto stainless steel, the VG films exhibit robust interfacial integration and preserve their vertically aligned, interconnected wall architecture. This structure enables a high-water contact angle of 128.5 degrees, indicating pronounced hydrophobicity, and effectively suppresses biofouling on stainless-steel surfaces as well as excellent corrosion resistance. These results suggest that VG offers a promising materials-based strategy for reducing biological contamination on surgical instruments and other biomedical devices.

In this study, Na3Zr2Si2PO12 (NZSP) solid electrolytes (SEs) were synthesized via a two-step solid-state reaction with first-step sintering temperatures varied between 1100 degrees C and 1250 degrees C to systematically investigate their effects on structural and electrochemical properties for sodium solid-state battery applications. Characterizations including X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance spectroscopy (EPR), and electrochemical impedance spectroscopy (EIS) were employed to analyze crystal structure, microstructure, elemental uniformity, and ionic conductivity. The sample sintered at 1200 degrees C (NZSP1200_700) exhibited the highest room-temperature ionic conductivity of 2.4 x 10(-4) S cm(-1). This superior performance is attributed not only to a high relative density of similar to 94.3 % and reduced grain boundary resistance but also to an optimized concentration of oxygen vacancies (V center dot(0), identified at g approximate to 2.003 via EPR), which facilitates Na+ transport. Electrochemical testing of Na|NZSP1200_700|Na symmetric cells showed stable cycling over 100 cycles at 0.01 mA cm(-2), with the overpotential maintained within +/- 0.05 V, indicating stable sodium electrode interfaces. Solid-state full cells using NaxFe0.5Mn0.5O2, as the cathode delivered an initial discharge capacity of similar to 110 mAh g(-1) at 0.01 A g(-1) and retained over 99 % Coulombic efficiency after 100 cycles, demonstrating high cycling stability. This work quantitatively elucidates how sintering temperature impacts crystallinity, densification, defect chemistry, and their combined influence on the Na+ conduction pathways and battery performance, providing important insights for tuning processing parameters to optimize NASICON-type solid electrolytes.

With the rapid development of technology and the rise of the electric vehicle industry in recent years, the demand and market requirements for energy storage devices have been increasing. In this trend, the development of lithium-ion batteries has been going on for decades and have gained valuable research experience and mature development technology from it. In this study, SiOx/biomass carbon composites were prepared through high-temperature sintering using silicon oxide and biomass carbon at various ratios. Among them, SiOx@PL900C (1:1) exhibited the best cycling stability, retaining a capacity of 495 mAh g(-1) after 200 cycles with a capacity retention of similar to 90%. In addition, the diffusion coefficient of SiOx@PL900C (1:1) (1.01 & times; 10(-12) cm(2) s(-1)) was higher than that of the unmodified SiOx (3.29 & times; 10(-13) cm(2) s(-1)). These results indicate that biomass-carbon coating effectively reduces both R-SEI and R-CT in the battery, lowering the charge-transfer resistance from 877.1 Omega to 102.4 Omega, accelerating Li-ion transport, and thereby further enhancing the electrochemical performance of the composite material. Finally, electrochemical performance of as-assembled LiFePO4/SiOx@PL900C pouch cells to demonstrate the practical application is presented.

Li 3 InCl 6 /VGCF composite coating on SC-NCM613 cathode targets simultaneous enhancement of ionic and electronic transport.

Solid-state Li-metal batteries (SSLMBs) are attractive for their safety and high energy density characteristics, enabled by solid-state electrolytes (SSEs) and lithium metal anodes. However, SSEs face challenges in ionic conductivity and interfacial stability. Herein, we develop composite solid electrolytes (CSEs) incorporating functionalized 2D graphene-based fillers, such as reduced graphene oxide, graphene oxide, and fluorinated graphene oxide (FGO), into a solid polymer electrolyte for LiNi0.8Co0.1Mn0.1O2 (NCM-811)-based SSLMBs. Among them, FGO exhibits the best performance, offering superior ionic conductivity (9.4 & times; 10(-4) S cm(-1) at 25 degrees C), a high Li+ transference number (0.60), and a wide electrochemical window (similar to 4.8 V). The Li+ transport behavior in the CSEs with various functionalized graphene materials is examined via density functional theory calculations. The improved Li+ mobility can be attributed to the positively charged C atoms bonded with fluorine groups. The calculations indicate stronger TFSI- binding on FGO, which facilitates Li+ dissociation and enhances Li+ transport. The Li||1FGO-CSE||NCM-811 cell delivers a high cathode capacity of 200 mAh g(-1) at 25 degrees C, retaining 95% of its capacity after 350 cycles. While the filler-free SSE exhibits relatively low Li+ conductivity and poor cyclability, the FGO-CSE enhances Li+ conduction and stabilizes both the anode and cathode interfaces, thereby achieving outstanding cell performance.

In this study, we developed a novel transition-metal oxide, Co3V3O8 (CVO), and synthesized it through a two-step hydrothermal and sintering process. To optimize electrochemical performance for lithium-and sodium-ion batteries, sintering temperatures of 500, 550, and 600 degrees C were investigated. Among them, CVO550 shows the best performance, delivering reversible capacities of 425 mAh g(-1) (Li+) and 71 mAh g(-1) (Na+) at 5 A g(-1), with stable cycling capacities of 906 mAh g(-1) and 153 mAh g(-1) after 100 cycles at 0.2 A g(-1) in lithium and sodiumion batteries, respectively. In-situ Raman spectroscopy reveals a Li+ desolvation threshold at 1.6 V, triggering electrode conversion, while Na+ desolvation occurs below 0.3 V with reversible local distortions. In-situ XRD confirms a low-strain host, characterized by reversible lattice breathing and absence of phase separation during Na+ insertion/extraction. Density functional theory calculations support these mechanisms and indicate a thermodynamically stable configuration governed by optimized Co/V charge distribution. A full sodium-ion pouch cell with a CVO anode and a Na3V2(PO4)(3) cathode delivers 5.6 mAh at 2 C and maintains stable operation over 200 cycles, demonstrating its practical potential.

All-solid-state batteries are regarded as promising next-generation energy-storage systems due to their potential to achieve energy densities exceeding 400 Wh kg-1. However, their practical implementation remains limited by interfacial instability, non-uniform metal deposition, and continuous electrolyte decomposition during cycling. In this work, a dual-sided polymer coating was introduced onto Na3SbS4 solid electrolyte pellets using a siloxane-based sodiated polyelectrolyte (AAM950), combined with sodium bis(trifluoromethylsulfonyl)imide, as an artificial interfacial layer. The conformal coating partially filled surface pores and reduced interfacial gaps, leading to improved solid-solid contact between the electrolyte and electrode. The optimized 7 & micro;L polymer-coated Na3SbS4 (NSS) pellet exhibited an ionic conductivity of 0.348 mS cm-1 at 55 degrees C. In addition, the Na2/3Fe1/2Mn1/2O2|Na-AAM950-NSS-Na-AAM950|Na cell delivered an initial discharge capacity of 137.4 mAh g-1, compared with 83.59 mAh g-1 for the bare NSS system at 0.02 A g-1, together with a capacity retention of 89.6% and an average Coulombic efficiency of 99.56% over 50 cycles at 55 degrees C. Although the polymer layer did not substantially increase the intrinsic bulk ionic conductivity of NSS, it effectively stabilized the electrode/electrolyte interface and promoted more homogeneous Na+transport during cycling. These findings demonstrate that dual-sided polymer modification provides an effective strategy for improving the practical cycling stability of Na3SbS4-based sodium all-solid-state batteries.

In this work, we investigate the transition metal oxide spinel $\text{Fe}_{2.99} \mathrm{V}_{3.01} \mathrm{O}_{8}$ using combined X-ray and neutron powder diffraction techniques to elucidate its crystal and magnetic structures. The results indicate that the compound retains a tetragonal crystal structure with space group $\mathbf{I 4}_{\mathbf{1}} /$ amd throughout the temperature range from 3.3 K to 475 K. The magnetic structure is described by the magnetic space group $I 4_{1}{ }^{\prime} / a m^{\prime} d$, and no structural or magnetic phase transition is observed within this temperature window. At low temperatures, the system exhibits a canted antiferromagnetic ordering. Magnetization measurements reveal anomalies near 30 K and 100 K, corresponding to the $\mu_{y}$ component exceeding $\mu_{z}$ and reaching its maximum value, respectively. A pronounced magnetic hysteresis associated with magnetic domain formation is observed at 2 K, which is significantly suppressed above 300 K. Specific heat measurements show a weak and broad anomaly around 180 K, which is likely associated with subtle lattice distortions rather than magnetic ordering.

Electrolyte composition strongly influences the cycling performance of tunnel-type Na0.44MnO2 (NMO), yet additive selection for this cathode remains largely empirical. Here, we evaluate a dual-additive electrolyte containing fluoroethylene carbonate (FEC) and nominally added trace sodium fluoride (NaF) in a carbonate-ester baseline to determine how the formulation affects Na+ solvation and electrode interfacial behavior. Raman spectroscopy and molecular dynamics simulations identify FEC as the principal additive that decreases Na+–EC coordination and promotes relatively greater anion participation in the first solvation shell; under the conditions examined, trace NaF contributes only modestly. The dual-additive formulation exhibits limited impedance growth during prolonged cycling, relatively balanced apparent Na+ transport during insertion and extraction, and largely reversible structural evolution of the tunnel framework, as observed by in situ synchrotron X-ray diffraction. Two-electrode Na||NMO cells using this electrolyte retain 95.6% of their cycle-2 capacity after 150 cycles at 1C, comparable to the FEC-only formulation (95.9%) and higher than the NaF-only (74.3%) and baseline (66.6%) formulations, while providing the highest discharge capacity at each rate tested. NMO||hard‑carbon full cells with the same electrolyte retain 88.2% of their cycle-2 discharge capacity after 130 cycles at 1C and achieve an average Coulombic efficiency of 99.84% over cycles 2–187.