The large-scale application of low-cost layered lithium manganese-rich oxides as cathode materials for lithium-ion batteries is still limited by their poor cycle life. It is seen that their structural degradation and particle pulverisation mechanisms on the fundamental understanding are essential to developing sustainable and green cathode materials. Herein, we report the cooperative Jahn-Teller distortion-driven early-stage degradation and local Jahn-Teller distortion-driven later-stage pulverisation mechanisms for monoclinic-LiMnO2 during repeated cycling. Importantly, the considerable dynamic lattice mismatch between the disordered tunnel and disordered layered/spinel structures is observed for the first time and will induce the presence of intergranular cracking. The dynamic lattice mismatch can be sensitively dependent on the initial Jahn-Teller distortion, accompanied by a butterfly effect and finally leading to particle pulverisation. This study demonstrates a possibly universal structural degradation mechanism in layered Mn-rich cathodes and provides fundamental insights into strategies to help develop highly stable layered cathodes for sustainable lithium-ion batteries. (c) 2026 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Topological semimetals are renowned for exhibiting large, unsaturated magnetoresistance arising from ultrahigh carrier mobility and electron-hole compensation. However, such behaviors remain poorly understood in iron-based superconductors that have been recently recognized to harbor rich nontrivial topology. Here, we combine angle-resolved magneto-transport measurements with first principles calculations to reveal the emergence and tunability of topological semimetals in ferropnictide Ba(Fe$_{1-x}$Co$_x$)$_{2+δ}As$_2$ epitaxial films, modulated by interstitial Fe. These states exhibit ultralow residual resistivity, coexisting high-mobility electron and hole carriers, and linear positive magnetoresistance below 110 K. Remarkably, the magnetoresistance becomes more pronounced when the magnetic field is applied parallel to the film plane, reaching an unsaturated 1206% at 56 T. Furthermore, superconductivity persists in these ferropnictide films, establishing them as a tunable platform for investigating the interplay among electron correlation, topology, and superconductivity.

Materials with 5d electrons show outstanding functional and structural properties. This Perspective systematically analyses the intrinsic electronic structures of materials with 5d electrons to enhance our understanding of their unique functions. Specifically, how the interplay among various factors, including strong nuclear attraction, relativistic effects, strong spin-orbit coupling, large orbital spatial extension, strong crystal field splitting and moderate electron correlation, determines the electronic structures. These electronic characteristics create opportunities for designing new materials and solutions for a variety of applications, including information technologies, quantum sciences, catalysis, aerospace and energy storage.

Industrial seawater electrolysis remains constrained in achieving both high catalytic activity and long-term durability, with key limitations including structural degradation and mechanical instability within catalyst layers. Here we show a self-adhesive high-entropy oxide sub-nanowire monolithic catalyst that overcomes both obstacles. The catalyst is synthesized under mild conditions and incorporates 14 metal elements into uniform ~1.2 nm sub-nanowires with strong intrinsic adhesion to conductive substrates, eliminating the need for external binders. It also features unconventional active sites that enable efficient and durable lattice oxygen activation while preserving structural integrity during prolonged operation. It exhibits overpotentials of 129 mV in 1 M KOH and 153 mV in 1 M KOH + seawater at 10 mA cm-2, and maintains continuous operation at 1,000 mA cm-2 for 4,700 h and 4,400 h, respectively. Integrated into an anion exchange membrane seawater electrolyser, it delivers 3,000 mA cm-2 at 1.70 V (80 °C) and operates continuously for over 3,819 h at 2,000 mA cm-2 under ambient conditions.

ABSTRACT Extracting lithium from seawater offers an additional Li source but is hindered by corrosion of Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (LAGP) and weak adhesion of conventional coating layers. Here we propose a permeation growth strategy to construct an intergrowth TiO 2 protection layer on a LAGP membrane (LAGP membrane with intergrowth layer) for long‐term stable lithium extraction from seawater. An acidic TiO 2 sol is spin‐coated onto a polished LAGP membrane and sintered, during which acid etching and Ti 4+ /Ge 4+ ion exchange generate a lattice‐matched Li 1+x Al x Ti 2‐x (PO 4 ) 3 /LAGP interfacial phase beneath a dense TiO 2 intergrowth layer. This intergrowth‐structure eliminates interfacial gaps, enhances peel strength and hardness, and provides continuous Li + transport pathways, delivering an ionic conductivity of 2.40 × 10 −4 S cm −1 at room temperature and excellent chemical stability in seawater. Applied in a lithium extraction device using natural seawater as anolyte and an organic electrolyte as catholyte, the LAGP membrane with intergrowth layer maintains integrity, Li + /Na + selectivity, and stable operation for 650 h, achieving a Coulombic efficiency of 97.4% and an energy consumption of 17.4 kWh kg −1 Li . This permeation growth strategy offers a general route to construct intergrowth‐structure Li ion‐sieve membranes with chemical stability and Li + transport for seawater lithium extraction.

Strain-induced self-assembly presents a promising avenue for constructing novel microstructures, which can be used to simulate natural creatures and fabricate complex devices. In this work, with crystalline ferromagnetic metallic SrRuO3 nanomembrane as a model system, we successfully realize the fabrication of micro-scale magnetic tubular structures. By utilizing the in-plane anisotropic lattice strain in SrTiO3/SrRuO3 bilayer grown on SrTiO3 (110) substrate, we demonstrate the precise control of orientation and diameter of resulting microtubes. More interesting is that the artificially fabricated microtubes exhibit radial curvilinear magnetism due to the spin-orbit coupling induced perpendicular magnetic anisotropy in SrRuO3 nanomembrane. This was confirmed by macroscopic magnetization measurement, which revealed the continuously-rotated magnetic moment along the radial direction. Moreover, the magnetoelectronic transport measurement on a single microtube reveals that the overall magnetoresistance is closely related to the local magnetic moment distribution in the curved structure. This behavior can be modeled by integrating the magnetoresistance contributions from all longitudinal strips of the radial-magnetized microtube. Our findings not only advance the understanding of magnetoelectric effects in curvilinear magnetism but also provide valuable insight and guidance in designing innovative spintronic devices.

Understanding the structural, chemical, and functional properties of materials is essential for advancing performance. Over the past two decades, transmission electron microscopy (TEM) has undergone transformative developments, with state-of-the-art imaging, diffraction, and spectroscopy establishing it as a cornerstone of materials characterization at the micro- to nanoscale. A key breakthrough has been the advent of pixelated direct electron detectors, which enable the recording of two-dimensional diffraction patterns at each probe position and have given rise to four-dimensional scanning transmission electron microscopy (4D-STEM). Analysis of 4D-STEM datasets provides rich information about strain distribution, crystallographic orientation, and variations in electric and magnetic fields across multiple length scales. Moreover, ptychographic reconstruction, achieved by decoupling the electron probe wave functions and specimen object functions, allows retrieval of quantitative phase information with atomic-scale precision, thereby surpassing the resolution limits of conventional TEM. This review summarizes the principles and recent applications of 4D-STEM, encompassing virtual detector imaging, strain and orientation mapping, electromagnetic field measurements, radial distribution function analysis, ptychography, and data acquisition strategies in functional materials. Finally, it highlights the challenges and future opportunities in advancing 4D-STEM toward deeper insights into material properties and the rational design of next-generation materials.

An electrocatalytic nitrate reduction reaction (NO3RR) over Cu-based catalysts represents an energetically feasible route for treating nitrogenous wastewater. However, its efficiency remains limited by the sluggish dissociation of H2O, which fails to supply active hydrogen (*H) in time to support the hydrogenation of nitrogenous intermediates. Herein, an in situ electrochemical reconstruction strategy is employed to fabricate FeCu-hydroxide nanoarrays directly on copper foam (R-FeCu-OH/CF NAs); owing to the superior hydrogen transfer ability from Fe sites to Cu sites, the synergistic catalytic process (*NO3 adsorption, *NO3-*NO2 and *NO2 hydrogenation) exhibits favorable thermodynamics. Spectroscopic and theoretical evidence indicates that Fe sites at Fe/Cu interfaces facilitate H2O dissociation, enabling efficient *H transfer to Cu. This process suppresses NO2- accumulation and *H coupling, leading to lower energy barriers for NO3- adsorption and *NO2/*NO to *NOH. The catalyst achieves up to 92% NO3- conversion and nearly 100% N2 selectivity, while providing a stability of up to 60 cycles and a retention of 98%. When deployed as the cathode in a Zn-NO3- battery, the catalyst delivers an open-circuit voltage of 1.27 V and a peak power density of 9.26 mW cm-2, outperforming previously reported electrocatalysts. This work elucidates hydrogen-transfer mechanisms and guides the design of efficient electrohydrogenation reactions.

Ruthenium phosphide electrocatalysts for the hydrogen evolution reaction (HER) still face challenges such as insufficient active site utilization and limited durability. This work addresses these challenges via a synergistic strategy that integrates heterojunction engineering with a hollow confinement structure, resulting in RuP2-Ni2P nanoparticles embedded within N,P-codoped hollow carbon spheres (RuP2-Ni2P/NPC). The interfacial coupling between RuP2 and Ni2P optimizes the electronic structure toward a near-ideal hydrogen adsorption energy, while the unique embedded architecture ensures abundant accessible active sites and exceptional structural robustness. As a result, the RuP2-Ni2P/NPC catalyst exhibits superior HER performance across a wide pH range, achieving ultralow overpotentials of 3 mV in 1 M KOH and 17.3 mV in 0.5 M H2SO4 at 10 mA & centerdot;cm(-2), ranking among the best of reported RuP2-based catalysts. It also demonstrates excellent long-term durability in both alkaline and acidic electrolytes. This work provides a feasible design strategy toward efficient and robust electrocatalysts for hydrogen production.

Na-ion batteries are promising energy storage technologies, yet cathodes suffer from structural instability during deep cycling, leading to a trade-off between energy density and long-term life. Here, we introduce a "local electron density engineering" strategy to address this intrinsic challenge. We propose that structural degradation originates from the withdrawal of electron density from lattice oxygen by a high-valence transition metal. By incorporating stable d10 (Zn2+) and d0 (Ti4+) ions, we create an electron-rich oxygen framework that acts as an "electron buffer", resisting this electron depletion. Reinforced further by Ca2+ pillars in the Na+ layers, our single-crystalline Na0.96Ca0.02Cu0.038Zn0.053Ni0.409Mn0.315Ti0.185O2 cathode exhibits a low volume change of similar to 4% under deep desodiation. In 26700 cylindrical full cells, it delivers an energy density of 181.2 Wh kg-1 and retains similar to 80% capacity rentention after 1000 cycles. These results establish a new design pathway for developing ultrastable, high-energy cathode materials for next-generation Na-ion batteries.

Abstract Lithium-rich layered oxides, characterized by Li ions in the transition-metal layers, can significantly increase battery energy density through the introduction of oxygen redox. However, these cathodes often suffer from substantial voltage hysteresis, leading to a considerable energy loss during discharge. Herein, we present an O3-type cathode, Li0.63[Li0.20Mn0.80]O2, through the spontaneous ion exchange of P3–Na0.60[Li0.20Mn0.80]O2 in the electrolyte, which retains the ribbon-ordered superstructure. This cathode exhibits a reversible oxygen reduction plateau within the 4.2–4.7 V voltage range, exhibiting minimal voltage loss (hysteresis) during the initial discharge. When the lower voltage limit is reduced to 3.0 V, the plateau disappears. In situ XRD and STEM indicate that there is no significant structural change. Further spectral tests and DFT calculations show that the reversible oxygen reaction is replaced by the Mn reaction during the charging process due to charge transfer, resulting in the disappearance of the discharging plateau. Our findings suggest the potential for lithium-rich layered oxide cathodes to operate without voltage hysteresis and suggest that structural degradation at high voltage is not the only factor causing irreversible oxygen reaction.

Electrochemical reduction of nitrate to nitrogen (N2) offers a sustainable pathway to close the nitrogen cycle and mitigate nitrate pollution. However, for Cu, Co, and other transition-metal catalysts, high N2 selectivity has mainly relied on breakpoint chlorination, which consumes large amounts of chlorine and poses secondary contamination risks. Here, we introduce a surface-oxophilicity strategy to steer the *N pathway, thereby enhancing both catalytic efficiency and intrinsic nitrogen selectivity. Among oxophilicity-modified Pd, Sn doping emerged as the optimal configuration. The resulting PdSn metallene aerogels achieve remarkable NO3 --N conversion (∼97%) and N2 selectivity (∼99%), together with long-term stability (>600 h) and broad tolerance to variable nitrate concentrations. In situ characterization and theoretical analyses reveal that Sn-induced oxophilicity strengthens nitrogen-oxygen intermediate adsorption, ensuring sufficient *N availability for N-N coupling while elevating the hydrogenation barrier of *N → *NH, thus suppressing NH3 formation. Integrated into a Zn-NO3 - battery and a customized gas-integrated flow electrolyzer, the catalyst enables efficient nitrate removal and nearly complete N2 selectivity, offering a promising platform for sustainable nitrogen recycling and energy conversion.

Neuromorphic systems based on spike-timing-dependent plasticity offer energy-efficient learning but face limitations in terms of adapting to high-frequency inputs, restricting their effectiveness in processing complex temporal information. Synaptic fatigue dynamics, analogous to biological short-term plasticity, can increase the effectiveness, but this feature is difficult to efficiently incorporate in hardware. Here we report a hybrid architecture in which arrays of memristors with distinct dynamics are paired to create synaptic elements with short-term fatigue and long-term memory. The elements consist of an interfacial dynamic memristor with high uniformity and intrinsic fatigue behaviour coupled to a hafnia-based one-transistor–one-non-volatile memristor. The design enables a hardware-efficient implementation of fatigue spike-timing-dependent plasticity, enhancing the temporal learning capabilities of spiking neural networks. We show that the resulting neural network can be used for unsupervised online learning with high adaptability to both rate- and timing-coded spikes, high noise resilience and superior performance over conventional spike-timing-dependent plasticity approaches. By coupling volatile memristors with short-term dynamics and non-volatile memristors with long-term dynamics, spiking neural network hardware can be created that exhibits fatigue spike-timing-dependent plasticity learning.

Both mechanical and electrochemical processes critically govern the performance of single-crystal Ni-rich cathodes of lithium-ion batteries. Although electrochemically induced lattice defects are widely regarded as detrimental to cycling stability, mechanically introduced defects during electrode fabrication are commonly assumed to be similarly harmful. Contrary to this prevailing assumption, we demonstrate that although mechanical compression does introduce various structural defects, transmission electron microscopy reveals that these pre-existed defects are self-passivated during cycling and contribute negligibly to degradation. Instead, densification process unexpectedly enhances both cycling stability and rate capability, primarily due to reduced porosity and improved electronic connectivity. We further identify that capacity degradation is dominated by lattice distortions arising from rapid c-axis contraction during the H2-H3 phase transition, which triggers strain accumulation, planar gliding, and crack propagation - all of which are significantly alleviated in densified electrodes. Molecular dynamics simulations corroborate these findings, showing compact electrode structure promotes more uniform lithium-ion extraction and mitigates stress concentration, thereby preserving the cathode's layered structure. These findings reveal the mechano-electrochemical coupling from electrode to lattice level, providing a multiscale perspective to optimize electrode manufacturing for durable high-energy batteries.

High-entropy alloy (HEA) nanomaterials are promising catalysts for proton exchange membrane water electrolysers (PEMWE), yet their crystalline structures have typically been restricted to thermodynamically stable phases. Here, using Au nanomaterials with distinct crystal phases as templates, we synthesize and stabilize Au@HEA core-shell nanostructures through a general and robust wet-chemical method in which the HEA is composed of up to ten metallic elements (Ir, Pt, Ni, Fe, Co, Rh, Pd, Ru, Cu and Mn). Phase-dependent water electrolysis is demonstrated as a proof-of-concept application. The hexagonal close-packed 4H-Au@4H-IrPtNiFeCo catalyst exhibits superior activity and stability for the acidic hydrogen evolution reaction, oxygen evolution reaction and overall water electrolysis compared with the conventional face-centred cubic IrPtNiFeCo catalyst. In a PEMWE at 60 °C, the 4H-Au@4H-IrPtNiFeCo catalyst achieves 3,000 mA cm-2 at only 1.90 V and maintains stable operation for over 1,200 h at 1,000 and 2,000 mA cm-2, with degradation rates of ~6.3 and ~15.7 µV h-1, respectively. This work offers a strategy for designing highly efficient and stable HEA catalysts with tailored phases for future practical water electrolysis.

The physical origin of controlling ferroelectric properties in defect-engineered Aurivillius-phase layered materials lies in the local polarization evolution mediated by structural defects. Nevertheless, the role of widely prevalent out-of-phase boundary (OPB) defects in configuring polarization remains unclear. This study uses Bi3.15Nd0.85Ti3O12 film, optimized with a HfO2 buffer layer, as a model system to elucidate the intrinsic mechanism behind the enhanced local polarization within the OPB defect regions. Atomic-scale quantitative analysis reveals that OPB defects enhance the in-plane displacement of B-site cations and co-align their out-of-plane polarization directions within the perovskite layers. This reconfiguration disrupts the intrinsic antipolar ordering by eliminating the antiparallel alignment of out-of-plane dipoles between adjacent pseudo-perovskite blocks in the pristine lattice. Strain and vacancy redistribution further promote the polarization configuration transition by disrupting charge compensation. These findings provide mechanistic insights into defect-modulated ferroelectricity and suggest a new approach for designing high-performance devices through strain and defect engineering.

Catalysts are core elements in the fields of modern chemical industry, energy conversion, and environmental protection. The precise regulation of their performance is crucial for achieving efficient, low-consumption, and sustainable chemical processes. With the rapid development of characterization techniques, especially real space transmission electron microscopy, catalytic research is undergoing a transformation from mean field analysis to the elucidation of local atomic-level structure-property relationships. This review focuses on the structure-property relationships of catalysts in real space and systematically reviews the core role of transmission electron microscopy techniques in revealing the intrinsic properties of catalysts across multiple scales. Starting from the regulation of potential functions of isolated atoms, the review discusses the effects of element selection, dual-atom synergy, heteroatom doping, and interface electric fields on the electronic structure and catalytic activity of single-atom catalysts. Subsequently, it conducts an in-depth analysis of the performance optimization mechanisms and characterization strategies caused by the symmetry breaking of degrees of freedom including lattice, charge, orbital, and spin as atoms aggregate to form nanoclusters and nanoparticles. Finally, the review prospects the complex correlations between the multi-scale dynamic structural evolution of catalysts and macroscopic performance in in-situ thermal, gas-phase, and liquid-phase catalytic environments, and emphasizes the key progress of a in-situ electron microscopy in capturing the dynamic behavior of catalysts in real reaction scenarios. This review aims to provide real space insights and envision the future direction of coupling the real space features of electronic structures and active sites with momentum space features of density of states and d-band theory for accurate prediction and rational design of high-performance catalysts.

Grain boundaries (GBs) can tailor the macroscopic properties of polycrystalline materials via their intrinsic structural and electronic states. However, as independent heterointerfaces, their role in stabilizing grain phases remains largely unexplored, especially at the atomic scale. Here we report that chemically ordered heterogeneous GBs in ZrO2 thin films act as active stabilizers of a metastable polar phase. The atomically sharp and ordered La(Sr)-Mn-O configurations at GBs are identified at the atomic scale. The resultant charge ordering and bond covalency of the GBs are validated by four-dimensional scanning transmission electron microscopy. This structural motif induces eg/t2g orbital ordering of Mn ions at GBs, modulating Zr-O bond strength to stabilize the polar phase. This work establishes a GB-centric paradigm for engineering nanoscale phase diagrams, offering a promising strategy for designing metastable functional materials via GB chemistry.

Ferroelectric charged domain walls (CDWs) with nanoscale thickness and bound charges are typically viewed as ultrathin, reconfigurable, and highly conductive two-dimensional components for domain wall nanoelectronics. Dimensional confinement of such polar topological structures has the potential to increase device density and unlock novel functionalities. We report 180° head-to-head and tail-to-tail CDWs exhibiting one-dimensional (1D) characteristics. These 1D CDWs are confined within the polar layers of ferroelectric ZrO 2 and have atomic-scale dimensions in both width and thickness. Quantitative analysis unveils a distinct screening mechanism of these walls whereby bound polarization charges are compensated by self-balancing oxygen occupancy. We demonstrate electric field–driven manipulation of these 1D CDWs, revealing the microscopic coupling between polarization switching and oxygen-ion transport.