We report the kinetics of the topotactic brownmillerite–perovskite phase transition in epitaxial strontium cobaltite (SrCoOx) thin films. Our findings reveal asymmetric switching kinetics between the oxygen‐deficient SrCoO2.5 and oxygen‐rich SrCoO3 phases, driven by the epitaxial strain state. Using phase‐field modeling, we demonstrate that nucleation and growth dynamics are governed by local oxygen concentration‐dependent diffusivity and surface oxygen flux, both of which are strain‐dependent. The perovskite phase exhibits higher strain tunability of these parameters compared to the brownmillerite phase, explaining the divergent kinetic pathways upon changes in epitaxial strain. Specifically, transitions on (LaAlO3)0.3(Sr2TaAlO6)0.7 (001) substrates are abrupt and nucleation‐dominated, characteristic of order–disorder transformations. Conversely, transitions on SrTiO3 (001) substrates are spatially uniform, with phase propagation originating from the film interface, characteristic of diffuse transformations. These results provide a framework for controlling topotactic transformation rates through strain engineering in functional oxides.

Solid electrolyte interphase (SEI) dissolution in sodium-ion batteries (NIBs) triggers electrolyte decomposition and gas evolution, resulting in capacity decay and safety issues. Lowering the solvation power of electrolyte mitigates SEI dissolution but decreases ionic conductivity. Here, we report a recessive solvent activation strategy, where the recessive solvent 1,2-epoxy-3,3,3-trifluoropropane (TFPO) alone dissolves NaFSI only sparingly, but its solubility is greatly enhanced by the addition of an activating solvent, diethylene glycol diethyl ether (DEE). By harnessing the tunable solvation behavior of the DEE-TFPO system, we designed a weakly solvating electrolyte (WSE) containing 24 vol% DEE, far below the bulk-solvent fractions typical of WSEs, and a high anion-to-DEE ratio. This low DEE content mitigates solvent-induced SEI dissolution, while the high anion-to-DEE ratio promotes anion-dominated solvation structure, forming a robust inorganic-rich SEI. These effects preserve high ionic conductivity while overcome the challenge of SEI dissolution. The optimized electrolyte enabled hard carbon || NaMn0.33Fe0.33Ni0.33O2 full cells to retain 80.0% capacity after 500 cycles and 99.5% capacity in 1.0 Ah pouch cells after 230 cycles with suppressed gas release.

The initial capacity loss in lithium-ion batteries arises from irreversible lithium consumption during solid electrolyte interphase (SEI) formation. Li2NiO2 (LNO) as a cathode pre‑lithiation agent compensates for this loss but suffers from poor atmospheric stability. Here, a uniform amorphous carbon coating is constructed on LNO via chemical vapor deposition (LNO@C). The carbon layer formed at 400 °C is dense, continuous, and tightly bonded to the LNO substrate, with an approximate thickness of 28 nm. As a result, LNO@C retains an initial charge capacity of 368.8 mAh·g-1 after 30 days of storage, whereas uncoated LNO decays to 277.6 mAh·g-1. Adding LNO@C to an NCM811||graphite full cell increases the initial capacity from 215.0 to 247.6 mAh·g-1 at 0.1 C, and the capacity retention reaches 90% after 200 cycles at 0.5 C, far superior to that of the cell without a lithium supplement (44%). Experimental characterizations confirm that the carbon layer suppresses H2O and CO2 penetration into the particle interior, reduces interfacial impedance, enhances Li+ diffusion, and optimizes the anode SEI film. This work demonstrates that carbon coating is a critical interface‑reinforcing strategy for practical lithium‑compensation technologies.

This study investigates the irradiation response of two L12-strengthened HEAs, (Ni2Co2FeCr)92Ti4Al4 (TiHEA) and (Ni2Co2FeCr)92Nb4Al4 (NbHEA), subjected to 6.4 MeV Fe3+ irradiation at 500 °C up to 30 dpa. Transmission electron microscopy (TEM) and atom probe tomography (APT) consistently showed that the Ti-containing HEA maintains L12-ordered structure and compositional stability better than Nb-containing alloys under irradiation. This difference is attributed to the distinct solute–defect interactions. Ti imposes a weaker hindering effect on vacancy mobility, allowing vacancies to remain mobile and participate in thermal reordering processes that counteract ballistic mixing, whereas Nb acts as a strong vacancy trap, suppressing the diffusion required for structural recovery. Irradiation-induced dislocation loops in the two alloys further exhibited different characteristics. TiHEA showed larger loops at lower number density, and NbHEA exhibited a higher density of smaller loops, consistent with their respective stacking fault energies and loop mobility. Nanoindentation results indicated that TiHEA exhibited a slightly higher irradiation hardening rate (27%) than NbHEA (23%), likely associated with a stronger order-strengthening contribution, given the better preservation of precipitate order in TiHEA under irradiation. These findings show the critical role of solute addition in designing radiation-tolerant high-entropy alloys.

The recycling of layered oxide cathodes (e.g., LiCoO2, LiNixCoyMnzO2 (x + y + z = 1)) hinges on the reduction of high-valence transition metals yet conventional methods are plagued by safety hazards, environmental risks, and high carbon emissions. Here, we develop an ethanol-aerosol-assisted roasting strategy that achieves a dual benefit: the cathode material itself acts as a catalyst to promote ethanol-aerosol pyrolysis, in situ generating syngas (H-2/CO), which in turn reduces the transition metals in the cathode for efficient lithium leaching. The residual H-2/CO in the tail gas can be captured and reused as an energy source. This approach combines the efficiency of gas-phase reduction with the safety of solid-phase reagents. Under the optimized conditions (600 degrees C, 30 min), the process achieved 97.3% lithium leaching efficiency with negligible transition metal dissolution (< 0.1%) and is expected to lower direct CO2 generation relative to conventional carbothermic reduction, owing to the involvement of H-2 as the reducing agent. To address the challenge of low solid-to-liquid ratio in subsequent leaching, we developed two scalable solutions: acid-water sequential leaching and ethanol-HCl co-atomization roasting, enabling high lithium extraction (> 97%) at ratios of up to 400 g L-1. Finally, battery-grade Li2CO3 is obtained from the leachate, while the Co-rich residue can be further utilized for resource recovery. This work not only demonstrates efficient cathode recycling, but also offers a novel catalytic strategy for sustainable syngas production.

Compared to single-surface-specific wetting materials, prewetting-induced switchable wetting materials offer advantages of simple operation, energy efficiency, and powerful functionality. They can meet operational demands in complex environments and demonstrate considerable potential across various fields. Current prewetting-induced switchable wettability materials are constrained by the preparation materials, fabrication strategies, separation performance, and stability. This paper reports the preparation of Ti(OH)4/BFC prewetting-induced switchable wettability (superhydrophilic/submerged superoleophobic and superhydrophilic/submerged superhydrophobic) oil-water separation membranes via a one-step solvothermal method. Ti(OH)4 utilizes the intermediate (HOOC-CH2-OH) as a molecular bridge to bond with BFC, constructing a heterostructure that leads to prewetting-induced switchable wettability. The membrane showed high water and oil fluxes (∼104 L·m-2·h-1) and over a 99% separation efficiency for gravity-driven oil-water mixtures. The chemical bonds connecting Ti(OH)4 and BFC contribute to the strong mechanical stability of the separation membrane. Prewetting induces a stable liquid film on the Ti(OH)4/BFC surface, enabling durable and high-flux oil-water separation.

Oxide twistronics extends moire engineering beyond van der Waals materials, offering a promising platform for accessing emergent interfacial phenomena arising from the strong coupling of lattice, charge, and orbital degrees of freedom in complex oxides. However, deterministic fabrication of high-crystallinity oxide moire superlattices over large lateral dimensions remains challenging due to the three-dimensional bonding network of oxides. Here, we demonstrate a scalable, generalized fabrication strategy that enables the formation of high-crystallinity oxide moire superlattices with clean, chemically bonded interfaces and precisely controlled twist angles down to nominal values of 0.1 degrees, achieving subdegree twist-angle accuracy across large contiguous lateral dimensions approaching the millimeter scale. Using NaNbO3 as a model system, we show that the resulting interlayer coupling drives pronounced structural reconstruction that modifies both the phase structure and ferroelectric domain configuration. Synchrotron-based X-ray 3D reciprocal space mapping reveals the emergence of a single-phase state in twisted bilayers, in contrast to the mixed-phase structure observed in single-layer membranes prior to twist assembly. The structural signatures are further consistent with gradual lattice rotation distributed along the thickness direction that may accommodate interfacial shear strain, distinct from reconstruction observed in van der Waals moire systems which primarily occurs through in-plane stacking rearrangement. This collective lattice response is correlated with twist-dependent nanoscale electromechanical modulations observed by piezoresponse force microscopy. These results establish a scalable materials platform for oxide twistronics and support the implementation of twist-engineered functionalities in practical, macroscale device architectures.

Sulfide solid-state batteries (SSBs) are pivotal next-generation energy storage systems. Their high future demand and substantially higher lithium content than traditional Li-ion batteries (LIBs) create valuable recycling opportunities. However, relevant research remains critically underdeveloped. Established LIB recycling methods are unsuitable due to sulfide solid-state electrolytes (SSEs), where S2- hydrolysis generates highly toxic H2S, involving environmental crisis. Here, we introduce a self-driven redox-coupled roasting strategy that leverages intrinsic solid-state reactions between oxidative transition metal (TM) cathodes and reducible SSEs. In-situ high-temperature XRD unravels the phase evolution, confirming the reduction of TMs to sulfides (Ni3S2, Co3S4) concurrent with the oxidation of S2- to SO42-. Meanwhile, in-situ high-temperature SEM visualizes the concomitant morphological transformations of the powder. Subsequent pH-modulated water leaching (pH = 5.0) enables precise single-step Li/TM separation, yielding 98.0% Li recovery with < 5.0% TM dissolution. This affords battery-grade Li2CO3 (99.6% purity). Furthermore, TM sulfides and hydroxyapatite constitute valuable by-products. Demonstrating 97.2% total Li recovery efficiency, this work pioneers an eco-friendly recycling paradigm for sulfide SSBs-transforming spent batteries into high-purity feedstocks, eliminating H2S hazards, and establishing a sustainable framework. This signifies a paradigm shift in SSB resource reclamation.

Recycling spent lithium-ion batteries (LIBs) demands time-efficient, short-process material recycling routes that enable rapid regeneration of battery materials. Here, we report a material-oriented recycling strategy in which synergistic acid chemistry enables ultrafast cathode dissociation, followed by spray pyrolysis-assisted regeneration of battery materials in a streamlined process. Cathode layers are rapidly exfoliated from aluminium (Al) foil within 5 min at 25 degrees C, with minimal Al dissolution (< 2.6%), allowing clean separation of the current collector. After removal of the detached Al foil, the cathode materials undergo ultrafast lattice deconstruction, achieving similar to 98% recovery of Li and transition metals (TMs) within 10 min at 85 degrees C at a record-high 300 g & centerdot;L-1 using near-stoichiometric acid consumption. Such accelerated kinetics originate from the synergistic acid chemistry that destabilizes transition-metal-oxygen frameworks in the cathode lattice. Beyond metal extraction, the leachate is directly converted via spray pyrolysis into Li2SO4 and TM oxide precursors, enabling subsequent synthesis of battery-grade Li2CO3 and regenerated cathode materials. This work establishes a short-process, high-throughput, material-oriented recycling paradigm for spent LIBs, offering a viable pathway toward sustainable closed-loop battery material recovery.

At the operating temperature (∼750°C) of solid oxide cells (SOCs), Ni diffusion has been revealed to cause aging degradations on catalytic performance, electronic conductivity, and mechanical failures. This work discloses that Ni diffusion during the high-temperature (∼1400°C) SOC fabrication process can severely decrease the oxide ion conductivity due to Ni segregation (up to ∼7 at.%) at the YSZ (yttria-stabilized zirconia) grain boundaries (GBs). Combining electrochemical tests and advanced electron microscopy, we reveal that higher Ni enrichment leads to thicker space charge layer and higher space charge potential, which generates a significant GB blocking effect for oxide ion diffusion. We have quantitatively estimated the ionic conductivity drop induced by Ni segregation at the operation temperature range. Utilizing the ultrafast high-temperature sintering technique, we successfully mitigate Ni segregation at GBs, which can double the ionic conductivity at 700°C. This work not only clarifies that Ni segregation at YSZ GBs can significantly plague the ionic conductivity but also demonstrates that mitigating Ni segregation at YSZ GBs is a new avenue to reduce the cell's ohmic resistance and boost the SOC performance.

The development of high-performance and durable air electrode is crucial for advancing reversible protonic ceramic electrochemical cells (R-PCECs). Herein, guided by structure-activity relationship principles, we develop a dual cation-doping strategy for the La0.5Ba0.5CoO3-delta (LBC) perovskite, incorporating small-sized Ca at the A-site and multi-valent Fe at the B-site to enhance its performance as an air electrode. Comprehensive characterizations and theoretical calculations reveal a synergistic effect: Ca doping enhances the structural stability by inhibiting Ba segregation, while Fe co-doping facilitates oxygen reduction and evolution by reducing the oxygen vacancy formation energy, thereby accelerating oxygen surface exchange kinetics. Consequently, the optimized dual cation-doped LBC air electrode exhibits exceptional electrochemical performance. The corresponding R-PCEC achieves a peak power density of 1.4 W cm- 2 in fuel cell mode and a current density of -2.8 A cm- 2 at 1.3 V in steam electrolysis mode at 600 degrees C, alongside demonstrating robust operational durability.

Al current collectors are widely adopted in nonaqueous batteries because of their low cost, high conductivity, and low density, yet their deployment in aqueous congeners (i.e., Zn-ion batteries) is largely precluded by concurrent issues of surface passivation and electrolyte-driven corrosion. Here, an on-site N-doped carbon-skinned Al current collector (NC@Al) is developed to resolve this longstanding dilemma. Enabled by an ultrafast Joule heating process, elevated temperature carbonization could be completed in seconds without thermally deforming the Al substrate, which renders a dense and continuous double-sided NC overlayer, affording favorable interfacial adhesion. Combined theoretical calculations and experimental diagnostics verify the NC overlayer simultaneously helps suppress the Al passivation-corrosion issue and promote uniform Zn deposition. As a result, symmetric cells based on NC@Al exhibit durable cycling beyond 3500 h at 0.5 mA cm-2/0.25 mAh cm-2. When paired with an iodine cathode, our constructed pouch cells with an active material loading of 25 mg cm-2 sustain stable operation for 1000 cycles under a stringent N/P ratio of 1.77. Technoeconomic analysis further highlights the energy-efficiency advantage of our route in practical manufacturing. This work establishes a strategy for employing commercially available Al current collector materials toward aqueous batteries.

All-solid-state battery stacks, as high-performance energy storage devices, face a critical mechanical issue during the clamping process: uneven interfacial pressure distribution between layers, which adversely affects their electrochemical performance and service life. To address this issue, this study proposes two auxiliary end-plate structures: the D-shaped plate and the trapezoid-like plate. Systematic optimization design procedures are also established, respectively. For the D-shaped plate structure, parameter sensitivity analysis, equivalent modeling, and a quadratic programming algorithm are employed to determine its optimal geometric dimensions. For the trapezoid-like plate structure, the design of experiments (DOE) and response surface methodology are applied to obtain the optimal parameter combination. Simulation results demonstrate that both optimized structures significantly improve the pressure uniformity within the battery stack, with improvements of 40.26% and 39.72%, respectively. Furthermore, this study summarizes two efficient optimization approaches, i.e. mechanical equivalent simplification and response surface methodology, providing valuable methodological references for similar structural design problems. The research findings offer direct guidance for component selection in engineering practice and contribute positively to promoting the engineering application of all-solid-state batteries.

A growing number of Galactic Wolf-Rayet (WR) stars, in particular WC and transitional WN/C (WNC) objects, have been reported at comparatively low luminosities. If confirmed, these low-luminosity WR stars provide stringent tests of stellar-evolution models, because their HR-diagram locations and surface compositions are highly sensitive to internal mixing and to the adopted WR-phase mass-loss history.We examine whether the HR-diagram positions and wind properties of low-luminosity WC/WNC stars can be reproduced by single-star evolutionary tracks at approximately solar metallicity, and we identify cases where additional channels (e.g. binary stripping) or dominant systematic uncertainties are likely required. Low-luminosity WNC/WC stars offer sensitive leverage on WR mixing and mass-loss prescriptions. A staged model-data comparison shows that revised WR winds can alleviate the luminosity-side tension for faint WCL stars, but the simultaneous requirements of temperature, surface composition, and WR-like wind density remain important. The WNC stars provide the strongest evidence that additional mixing, stripping, or binary-related channels may be required.

Abstract Lithium (Li)-free cathodes represent an important class of electrode materials for Li-ion batteries, but pre-lithiation is required when they are paired with graphite anodes. Existing pre-lithiation strategies typically suffer from limited controllability and/or nonuniform lithiation, limiting the long-term stability of the cells. Here, an integrated cell design is proposed that incorporates an auxiliary Li electrode to enable precise, efficient, and thermally controlled pre-lithiation within a single cell configuration. By reconfiguring the electrical connections, the cell can be seamlessly switched between pre-lithiation and normal cycling modes. Using sulfurized polyacrylonitrile (SPAN) as a representative Li-free cathode, the (Li|Gr)||SPAN integrated cell delivers an unprecedented 5000-cycle lifespan. Moreover, the integrated design enables repeated Li replenishment during cycling, effectively restoring capacity and extending cell lifetime. The universality of this strategy is further validated with lithium titanate-based cells. This work establishes a universal integrated cell design for ultralong-life full cells with Li-free cathodes.

Employing thin Li films for contact prelithiation holds great promise for high-energy-density Li-ion batteries. However, it is challenging to obtain thin, uniform, and robust Li films with controllable areal capacity for practical battery assembly and manufacturing. Here, we report built-in thin Li films, by depositing Li on the separator or the copper (Cu) current collector via vacuum evaporation, to compensate for the initial Li loss in Liion batteries. The built-in strategy endows the thin Li films with robust substrates compatible with roll-to-roll processing, allows them to be directly assembled into batteries, and enables anode prelithiation during the subsequent resting stage. Moreover, we demonstrate that the thin Li films can be flexibly adjusted in thickness from submicrometer to micrometer, to achieve precise prelithiation in varied battery systems. The evaporated Li exhibits a high utilization efficiency of 97% and is almost completely consumed during prelithiation, leaving negligible residue that could interfere with Li+ or electron transport. The prelithiation effects of thin Li films are validated in full cells using low-Coulombic-efficiency Si/C anodes and dry-processed graphite anodes, respectively, exhibiting significant increases in energy density. Importantly for practical application, the fabricated thin Li films exhibit satisfactory air stability even under harsh conditions with 17% relative humidity.

Thermal runaway of a Ni-rich LiNi x Co y Mn1-x-y O2 (NCM, x >= 0.8) cathode-based lithium ion battery (LIB) remains as a key safety concern for its utilization in power batteries, necessitating the precise evaluation protocol for the thermal stability of an NCM cathode. Herein, we reveal that conventional-sampling methods encounter a significant self-discharge issue during cell disassembly, artificially lowering the cathode's state of charge (SOC) and leading to inaccuracy of thermal stability evaluation. To address this, we developed a cryo-sampling protocol to disassemble the coin cells by flash-freezing in liquid nitrogen. This technique immobilizes the electrolyte, effectively blocking ionic transport pathways and preserving the cathode's intrinsic SOC by suppressing parasitic lithium redistribution. By coupling this method with multiscale characterization (in situ XRD, DSC-TG, and cross-sectional electron microscopy), we systematically elucidated the high-temperature failure mechanisms of single-crystal LiNi0.88Co0.05Mn0.07O2 (Ni88). Results show cryogenically disassembled cathodes exhibit similar to 20% higher residual capacity retention and 15 degrees C earlier onset of oxygen release compared with conventionally processed samples, confirming that SOC preservation critically reshapes thermal degradation pathways. The cryo-disassembled electrodes further revealed accelerated phase transitions (layered-to-spinel/rock-salt) and anisotropic microcrack propagation at 190 degrees C, phenomena masked in conventional sampling. This work establishes a methodological framework for the reliable thermal stability assessment of Ni-rich cathodes while revealing SOC-dependent lattice oxygen release behavior and its correlation with microcrack formation and propagation, offering actionable strategies for battery safety enhancement.

The direct regeneration of spent cathodes stands out as an environmentally and economically benign strategy within the battery ecosystem, eclipsing the cumbersome metallurgical approaches. Before addressing the lithium loss and structural degradation, it is crucial to focus on the residual contaminants within the spent cathode collected from retired Li-ion batteries after industrial exfoliation processes. Here, comprehensive characterizations and calculations show that in contrast to metal scraps, the electrolyte decomposition after battery operation and heating exfoliation uniformly coat the particle surfaces of cathodes, severely impeding the reuse and rejuvenation of LiNixCoyMnzO2 (NCM) cathodes with limited degradation by obstructing lithium diffusion. Considering the high costs and environmental risks of organic systems, we further propose a minute-level water-based pretreatment to purify the spent cathode and selectively eliminate these stubborn impurities that can deteriorate the interfacial chemical state, even after prolonged high-temperature heat treatment. Combined with a solid-state regeneration process, a purified 250k-miles-serviced (8 year) cathode could be rejuvenated to match the pristine one's capacity and cycling retention, displaying a 1.9-fold increase in average lithium diffusivity for charging and 43% enhanced capacity retention after 200 cycles compared with the unpurified one. Our study underscores the critical role of previously overlooked chemical residuals in facilitating the practical direct regeneration of retired lithium-ion batteries.