Abstract Enabling fast charging conditions in high energy density batteries is crucial for supporting the electrification of the transportation sector. Here, we introduce a strategy to support fast charging in lithium metal batteries by using atomic layer deposition to coat the copper current collector with a resistive Al2O3 thin film. The film constrains electron transfer to low-resistance defect sites, leading to the regulation of Li+ ion transfer and concentration profiles. Results show that limiting nucleation sites promotes the lateral growth of beneficial low-surface-area lithium deposits at current densities of up to 20 mA cm–2, an effect attributed to the radial diffusion of Li+ ions. We also show that the Al2O3 thin film incorporates a greater degree of beneficial inorganic species and LiF into the solid electrolyte interface at high current densities. For charging rates of 5 mA cm–2, the cumulative benefits allow cells with the resistive Al2O3 coating to achieve Coulombic efficiencies nearly 8% greater than bare copper over the first 100 cycles and support an additional 100 cycles at Coulombic efficiencies above 80% in carbonate electrolytes.

Background: Osteochondral defects pose significant clinical challenges owing to the complex anisotropic collagen alignment of osteochondral tissue and its limited self-healing capacity. Although mechanically biomimetic scaffolds have been widely applied in osteochondral repair, existing scaffolds exhibit limited structural and functional biomimicry, resulting in osteochondral repair efficacy that requires further improvement. Technology: Bioinspired by the unique collagen fiber alignment of natural osteochondral tissue, this study developed a technology of magnetically guided ordered biphasic scaffold combined with gradient magnetic field stimulation. Via alkaline dissolution and thermal crosslinking, Fe3O4 nanochains (NCs) were horizontally oriented in the agarose-based cartilage phase and vertically oriented in the poly(ethylene glycol) diacrylate/agarose-based subchondral bone phase. This scaffold system synergized with a 3–15 mT gradient magnetic field (MF) to enable the integrated repair of osteochondral defects. Results: We adjusted the scaffold's magnetism by modulating the content of Fe3O4 NCs, and further investigated the impacts of the magnetic ordered scaffolds and external MF on the differentiation of bone marrow mesenchymal stem cells. Results showed that the cartilage-phase scaffold (0.025 % w/v NCs, 0.27 emu/g) upregulated type II collagen (chondrogenesis), while the subchondral bone-phase scaffold (1.0 % w/v NCs, 1.20 emu/g) boosted osteogenic differentiation. Specifically, 3 mT static MF enhanced chondrogenesis via ECM-receptor signaling, while 15 mT static MF stimulated osteogenesis by activating PI3K/Akt pathway. Animal studies demonstrated that the magnetic biphasic hierarchical scaffold combined with 3–15 mT gradient MF significantly improved osteochondral repair, including nearly double the new subchondral bone volume fraction, a smoother cartilage surface, and collagen fiber alignment that more closely resembled natural osteochondral tissue. This work highlights the potential of the magnetic ordered scaffold-gradient MF technology in osteochondral repair, and is further poised for synergistic development with 3D bioprinting, intelligent manufacturing, and single-cell sequencing, injecting new impetus into the clinical translation of magnetic tissue engineering.

The practical implementation of lithium metal anodes has been hindered by uncontrollable dendrite formation and interfacial instability. This study presents a defect engineering of multiplayer hexagonal boron nitride (h-BN) that enhances ionic conductivity through argon ion irradiation. A cell-level demonstration was performed using commercially available, large-area CVD-grown h-BN films subjected to industrial-scale argon ion implantation. Direct evidence was provided by integration of these exfoliated flakes into a hybrid microfluidic-microelectronic chip, confirming that controlled vacancy defects transform h-BN into an efficient lithium-ion conductor while preserving its intrinsic electrical insulation. The results confirmed improved lithium-metal anode stability, achieving dendrite-free cycling with Li plating/stripping Coulombic efficiencies exceeding 99.5% for about 1000 cycles. Further assembly of irradiated h-BN in lithium-sulfur batteries effectively mitigates the polysulfide shuttle effect, sustaining over 97% specific capacity around 300 cycles. These results establish a robust, scalable interface engineering route for next-generation lithium metal batteries that combine high ionic transport with excellent electrical insulation.

Aqueous zinc batteries offer safety and cost-effectiveness for grid-scale energy storage although the electrochemical and chemical corrosion of zinc in water results in complex Zn species and 3D morphology, ultimately degrading battery performance. Thus far, the atomic and nanoscale 3D structure of the electroplated Zn complex remains unclear. Here, by employing advanced transmission electron microscopy, particularly cryogenic electron tomography, we resolve the preserved 3D architecture of electroplated zinc. A hierarchical solid-electrolyte interphase (SEI) comprising two critical structures that could impact battery performance is delineated-an epitaxial ZnO nanolayer on a Zn nanoplate as the inner SEI and petal-like zinc hydroxide sulfate (ZHS) flakes emerging from the edges of a Zn-ZnO crystal as the extended SEI. We discovered three epitaxial conditions of ZnO on electrochemically plated Zn nanocrystals: (0001)ZnO ∥ (0001)Zn, (10[Formula: see text]0)ZnO ∥ (10[Formula: see text]0)Zn and (0001)ZnO ∥ (10[Formula: see text]0)Zn. This complex Zn-ZnO-ZHS structure implies a correlation between the zinc-crystal edges and the heterogeneous chemical environment, which can be correlated with the zinc-texture- dependent battery performance.

Fluorinated diluents have been widely adopted in lithium metal batteries in recent years and represent one of the most successful strategies for stabilizing the electrode-electrolyte interphase. Because these molecules interact only weakly with alkali metal ions and are largely excluded from the primary solvation shell, they are generally considered chemically inert. Here, however, we show that incorporating fluorinated diluents into sodium metal electrolytes unexpectedly triggers severe sodium corrosion, revealing a striking contrast between lithium and sodium systems. This behavior motivated a systematic investigation of the underlying reaction mechanism, suggesting that fluorinated diluents may not be as chemically inert as previously assumed. We propose that PF5, generated from NaPF6, catalyzes the defluorination of fluorinated diluents in the presence of sodium metal, producing NaF and carbonaceous decomposition products. Extending this study across different salts, fluorinated diluents, and alkali metals further reveals that this behavior is broadly observed across diverse electrolyte chemistries and alkali metal systems. Beyond explaining this unexpected reactivity of fluorinated diluents, we leverage these mechanistic insights to establish a new strategy for controlled in situ NaF formation that stabilizes the interphase. By tuning the diluent structure and concentration, we regulate the extent of this reaction to promote beneficial NaF formation, enabling stable anode-free sodium metal batteries cycling for over 800 cycles.

Lithium metal batteries offer high energy density but suffer from persistent interphase instability, where continuous corrosion, solid electrolyte interphase (SEI) growth and poor lithium deposition morphology remain key barriers to long cycle and calendar life. Here, we introduce a novel concept of dynamic monolayers on Li metal anodes, consisting of electric field-responsive molecules that assemble into packed, structured layers at the lithium interphase under an applied voltage. We employed electrochemical quartz crystal microbalance with dissipation monitoring for in situ verification of the field responsiveness and packing behavior of these molecules. Dynamic monolayers with stronger packing are found to promote more inorganic-rich SEI and chunkier lithium growth, as directly observed by cryogenic X-ray photoelectron spectroscopy and operando optical microscopy. Together, these interfacial improvements translate into enhanced Coulombic Efficiency, reduced overpotential, and improved long-term cycling stability across Li||Cu, Li||Li, ultrathin lithium (20 μm) and anode-free NMC811 configurations. Dynamic monolayers potentially provide a broadly applicable approach for tackling interfacial challenges across a range of alkali metal battery systems.

Lithiophilic and conductive TiN-coated copper current collectors facilitate the formation of faceted crystalline lithium seeds at moderate current densities.

The solid-electrolyte interphase (SEI) on lithium metal forms through electrolyte reduction at a dynamically evolving metal surface, yet how its chemistry and spatial organization develop during lithium plating and stripping remains poorly understood. Here, using a 1,2-dimethoxyethane (DME)/1 M lithium bis(fluorosulfonyl)imide (LiFSI) electrolyte system, we show that three-dimensional lithium growth drives spatiochemical segregation of interphase products into chemically heterogeneous domains that are mechanically reorganized during stripping into a porous electrolyte-retaining framework. Correlative X-ray photoelectron spectroscopy, scanning electron microscopy, nanoscale secondary ion mass spectrometry (NanoSIMS), and synchrotron X-ray absorption spectroscopy reveal that FSI--derived inorganic species, dominated by LiF, become enriched in regions spatially decoupled from oxygen-containing phases near the lithium surface. Stripping-induced contraction compacts these chemically distinct domains into confined intergranular volumes, where supersaturation promotes precipitation and consolidation, yielding a porous SEI that retains electrolyte-derived species within a buried pore network beyond the reach of surface-sensitive probes. Spatiochemical segregation thus couples interfacial reaction pathways to lithium chemo-mechanics, dictating interphase composition, architecture, and permeability. These findings establish a chemo-mechanical framework for SEI evolution and suggest strategies to mitigate electrolyte retention and interphase instability in lithium-metal batteries.

Aqueous batteries typically rely on water-based electrolytes containing dissolved ionic compounds to supply mobile charge carriers, establishing a design paradigm in which water functions primarily as an electrochemically inert solvent. Within this framework, the intrinsic self-ionization and ion-conducting capabilities of water remain largely overlooked in battery operation. Here, we demonstrate that water can serve as the sole electrolyte, offering a wide stability window, for a water-dissociation battery by pairing a hydroxide-hosting cathode with a proton-hosting anode. The resulting water-battery full cell exhibits the potential as a storage battery with an active mass loading of 31 mg·cm–2. In addition, water can serve as an electrolyte for a rocking-chair proton battery, even in its frozen state—ice—as a solid electrolyte. These results reveal the underappreciated ion-transport capability of water and open an avenue toward safe, sustainable, and low-cost aqueous batteries.

Lithium metal batteries (LMBs) offer high energy density, but interfacial charge-transfer kinetics remain a bottleneck for high-rate operation. In this work, we construct a library of 12 ether solvents with systematic variations in symmetry and fluorination, confirming that molecular asymmetry is an important feature that results in enhanced Li+ redox kinetics and more stable solid electrolyte interphases on Li0. Furthermore, we developed a mechanistic understanding of the underlying process. We show that more tilted dipoles and lower moments of inertia strongly correlate with higher exchange current densities. Among the solvents in our study, the asymmetric F5MPE (1-methoxy-2-(2,2,3,3,3-pentafluoropropoxy) ethane) molecule, a previously unreported solvent molecule, enabled >170 stable cycles in high-rate Li||NMC full cells, outperforming the previously reported best single-salt-single-solvent ether solvent, F5DEE molecule. Overall, this work links molecular-level information with the behavior at electrochemical interfaces and provides an understanding of molecular design considerations for next-generation electrolytes tailored for high-power, fast-charging LMBs.

This study developed a simple strategy for bone organoid construction using GelMA/PEDOT:PSS hydrogel beads (fabricated via pipette extrusion-UV crosslinking) combined with electrical stimulation (ES). The hydrogel beads exhibited uniform size of 2.29 +/- 0.13 mm and porous structure of 100-200 mu m pores. ES (75 mV/mm, 75 Hz, 80 % duty cycle) triggered Ca2+ influx in HEK293T cells with 6-8 min and upregulated Opg expression in BMSCs. The combination of BMSCs-laden hydrogel beads and ES (20 min every other day) enhanced Osx/Runx2 expression post-osteogenic induction. This low-cost, facile system shows potential for bone organoid engineering.

The efficiency of monolithic perovskite/silicon tandem solar cells hinges on the transparent conductive interconnect layer, where the p-type component plays a pivotal role in enabling efficient hole transport and recombination. Herein, we systematically investigate RF magnetron sputtering deposition of the wide-bandgap p-type nickel oxide (NiO) films, with precise control of the O-2/Ar gas flow rate. By tailoring the vacancy concentrations and Ni3+/Ni2+ ratio, we modulate its p-type conductivity and optical transparency, achieving a high hole concentration of 1.68 & times;10(18) cm(-3) and minimal absorption (<3%) at 800 nm for a 20-nm-thick film. X-ray photoelectron spectroscopy and temperature-dependent electrical measurements reveal that Ni vacancy (V-Ni '') defects form the dominant acceptor level with an activation energy of 0.23 eV. The observation of barrier-free non-alloyed Au/p(+)-NiO contact inspired the fabrication of Au-related defect-assisted tunneling diode. By introducing a sub-monolayer dose of gold (Au) at the p(+)-NiO/n(+)-Si heterojunction interface, we attained a tunneling diode with a low specific contact resistance of 0.93 Omega & centerdot;cm(2). Combination of the p(+)-NiO/Au/n(+)-Si tunneling diode with a TOPCon silicon solar cell yields negligible fill factor loss. This study not only elucidates the defect-driven conduction mechanism in NiO but also demonstrates its practical viability as a cost-effective, scalable interlayer for next-generation tandem photovoltaics.

Metastable states provide unique opportunities to access functional materials inaccessible through conventional equilibrium pathways. Here, we employ this path dependency to enable safe storage and supplementation of capacity in lithium (Li) batteries, compensating for irreversible loss of Li caused by its high reactivity. We introduce a strategy of storing Li as a metastable Li-Cu alloy phase with characteristic thermo-electrochemical hysteresis—the phase is accessible only through a thermal process, inhibiting electrochemical re-alloying with Cu during cycling. The Li-Cu current collector (CC) demonstrates on-demand capacity extraction of up to 2 mAh cm−2 for extended cycle life in Li batteries. The high extraction potential of the Li-Cu alloy (1.2 V vs. Li/Li+) allows intentional activation by a designed protocol while otherwise remaining inactive within the conventional operating window. This approach transforms CCs into a Li reservoir with on-demand capability via hysteretic pathways, offering a promising design platform for high-energy-density batteries.

Anode-free lithium metal batteries (AFLMBs) offer unparalleled energy density by eliminating excess lithium, making them a transformative candidate for next-generation energy storage. However, their commercialization faces significant challenges, including uncontrolled lithium dendrite growth, interfacial instability, and the limitations of conventional copper current collectors, which suffer from excessive weight and poor lithiophilicity. This study presents a breakthrough mercaptopropyl trimethoxysilane (MPTS)-functionalized MXene current collector that enables stable, high-efficiency AFLMB operation without pre-lithiation requirements. Through our study, we demonstrate that the Si-O structure-rich surface of MPTS-MXene facilitates a homogenous Li-ion flux, while its mechanically robust lamellar architecture promotes dendrite-free, compact lithium deposition. Moreover, the engineered interface fosters the formation of LiF-rich solid-electrolyte interphase (SEI), drastically reducing parasitic reactions and achieving an exceptional Coulombic efficiency of 99.15% at 2 mAh cm-2. When integrated into MPTS-MXene||LiFePO4 full cell, the system demonstrates outstanding cycling stability (99.60% efficiency) and retains 57.79% capacity over 100 cycles. A critical advantage of the MPTS-MXene collector is its ultralight weight, only 15% of that of the copper per unit volume. By correlating MXene nanoengineering with electrochemical performance, this work provides a material-by-design blueprint to replace copper current collectors, paving the way for practical anode-free batteries with enhanced energy density and longevity.

Aqueous zinc (Zn) batteries are among the most promising candidates for safe, low-cost, and sustainable grid-scale energy storage. However, their practical application is significantly constrained by inhomogeneous Zn electrodeposition and the competitive hydrogen evolution reaction (HER). Here, we introduce an electrodeposition architecture to mitigate these challenges. Using atomic layer deposition, we coat the copper current collector with ZnO and Al2O3 nanofilms-positioned below the plated Zn. Our strategy marks a significant departure from previous works in which thin films are situated above Zn foil to function as artificial solid electrolyte interphases. Notably, we achieve substantial performance improvements with our 2-nm-thick ZnO coatings, including long cycle life (>1,400 cycles) and high Coulombic efficiencies (>99.8%). Our mechanistic investigation suggests that these improvements arise from HER suppression and controlled Zn morphology. This work offers an interface engineering approach to fundamentally understand Zn nucleation and growth processes. We anticipate that our electrodeposition architecture could be applied to enhance the cyclability of other aqueous battery systems.

The dynamic behaviors of metallic lithium (Li0) in Li-based batteries including the formation of various morphologies, corrosion, isolation, and spatial distribution affect the cycle life and safety. However, analysis on formation mechanisms or governing factors of Li0 is largely limited by the lack of experimental techniques to chemically and spatially identify low-Z elements from nano- to macroscale. Here, we demonstrate that staining Li0 with high-Z elements via redox reactions effectively enhances its visibility under an electron beam or X-rays. We find that heavy metal ions (Mn+) can be reduced by Li0 and nucleate as nanoparticles (NPs) on surfaces, staining effectively for direct visualization. Our results demonstrate that inactive Li0 embedded within residual SEI can be visualized, thereby revealing correlations between its distribution and its electrochemical performance such as Coulombic efficiency (CE). Our new technique represents a new analytical characterization tool to spatially track previously "invisible" internal components in batteries.

Twisted epitaxy enables precise orientation control of nanostructures confined within van der Waals (vdW) gaps. Here, we investigate the moiré and electronic structure of a representative twisted epitaxial system, where Au nanodiscs are grown inside twisted bilayer MoS2 with a 6° interlayer twist, inducing a 3° symmetrical misalignment of Au relative to each MoS2 layer (MoS2-Au-MoS2). Using multislice electron ptychography (MEP), we resolve the three-dimensional "moiré-of-moirés" structure of MoS2-Au-MoS2 with atomic resolution. Electron energy loss spectroscopy (EELS) shows that MoS2 encapsulation significantly reduces the plasmon energy of Au nanodiscs compared with their unencapsulated counterparts. Furthermore, first-principles calculations reveal that Au insertion alters the electronic band alignment near the Fermi level of bilayer MoS2. Our results introduce a twisted MoS2-Au-MoS2 heterostructure as a structurally and electronically rich material system and establish twisted epitaxy as a new strategy for moiré engineering and the synthesis of 2D-confined materials with tunable optoelectronic properties.

The Haber-Bosch process for ammonia synthesis contributes up to similar to 3% of global greenhouse gas emissions. Plasmonic catalysts strongly concentrate light and can alter the reaction intermediates via out-of-equilibrium processes, providing the potential for an alternative, less-energy-intensive pathway to synthesize ammonia. Here we show that gold-ruthenium (AuRu) bimetallic nanoparticles can synthesize ammonia at room temperature and pressure using visible light. We create AuRu alloys with varying compositions and achieve ammonia production rates of similar to 60 mu mol per gram of catalyst bed per hour. In situ infrared spectroscopy reveals that light accelerates the hydrogenation of nitrogen intermediates compared to conventional thermal catalysis. Through computational modelling, we demonstrate that photo-excited electrons enable associative hydrogenation pathways for nitrogen activation rather than direct nitrogen-nitrogen bond breaking. This light-assisted mechanism requires both hydrogen and light working together to overcome the nitrogen activation barrier, mimicking how biological enzymes produce ammonia naturally and providing fundamental insights for developing sustainable, energy-efficient chemical synthesis.

Sodium-ion batteries (NIBs) are increasingly becoming commercially viable alternatives to lithium-ion batteries (LIBs), driven by sodium’s lower cost and greater resource availability. However, current NIB technology still falls short of established LIB systems, such as those based on LiFePO4, in both cost efficiency and energy density. Although since the early 2020s, industrial advances have raised NIB energy densities to around 175 Wh kg−1, performance remains limited by the relatively low specific capacity (typically 200–350 mAh g−1) and low tap density (0.3–1.0 g cm−3) of the prevailing hard carbon anodes. This Review analyses emerging anode materials that could unlock higher-energy and lower-cost NIBs, with a focus on high-capacity hard carbon and alloy-based systems. We discuss the latest progress, fundamental challenges and future directions in these anode materials across the key themes of electrode design, structure–property engineering and characterization. By offering forward-looking insights into the rational design and optimization of anode materials, this Review aims to accelerate the research and development of commercially viable NIBs and support the broader advancement of energy storage technologies. Sodium-ion batteries are promising low-cost alternatives to lithium-ion systems yet limited by underperforming anodes. This Review highlights advances and challenges in hard carbon and alloy-based anodes, outlining design strategies to boost capacity, stability and commercial viability of next-generation high-energy sodium-ion batteries.

Rational management of lithium polysulfide (LiPS) transport is essential for stable, high-energy-density Li-S batteries. We introduce a freestanding, self-segregated trilayer polymer electrolyte (TLE) that forms two layers of nanometer-thin, ion-selective coatings at the cathode and anode interfaces by autonomous phase separation of two immiscible polymers while preserving a highly conductive bulk matrix. In Li-S cells, these coatings simultaneously repel dissolved LiPS at the sulfur cathode and stabilize lithium plating and stripping at the Li metal anode without sacrificing ion transport. Operando optical cell monitoring and theoretical modeling reveal that the dual-functional coatings are responsible for stable Li metal anode operation and effective shuttle suppression. The TLE enables an initial discharge capacity of 1369 mAh g-1 (81.7% of theoretical) and maintains a stable capacity over 50 cycles at 0.2C. Fabricated by a single-step casting process, this scalable electrolyte membrane offers a practical route to durable, all-solid-state Li-S batteries.