http://onlinelibrary.wiley.com/rss/journal/10.1002/(ISSN)1521-4095

This study unveils a superconducting state in undoped parent compound PrNiO2 thin films, challenging previous views on nickelate superconductivity. Through scanning transmission electron microscopy and spectroscopic techniques, the research demonstrates the high structural quality and distinct electronic properties of the thin films grown by pulsed laser deposition. While requiring an independent verification, this result suggests that the self-doping mechanism is sufficient for superconductivity and the reported phase diagram of infinite-layer nickelates might need a revision.

Several reports about infinite-layer nickelate thin films suggest that the superconducting critical temperature versus chemical doping phase diagram has a dome-like shape, similar to cuprates. Here, a highly reproducible superconducting state in undoped PrNiO2 thin films grown on SrTiO3 are demonstrated. Scanning transmission electron microscopy measurements show coherent infinite-layer phase with no visible stacking-fault defects, an overall high structural quality where possible unintentional chemical doping or interstitial oxygen, if present, sum well below the measurable threshold of the technique. X-ray absorption measurements show very sharp features at the Ni L3,2-edges with a large linear dichroism, indicating the preferential hole occupation of Ni1+-3dx2−y2${\rm d}_{x^2-y^2}$ orbitals in a square planar geometry. Resonant inelastic X-ray scattering measurements reveal sharp magnon excitations of 200 meV energy at the magnetic Brillouin zone boundary, highly resonant at the Ni1 + absorption peak. The results indicate that, when properly stabilized, infinite-layer nickelate thin films are superconducting without chemical doping.

This review explores the multiscale architectures and functional mechanisms of biopolymers and bioinspired materials, from hierarchical structures to AI-powered methodologies. It covers sustainable configurations, multiscale modeling techniques, and AI applications for enhancing functionality, biodegradability, and design. The work concludes with a forward-looking perspective on biopolymer advancements and potential for broad lifecycle impacts in advanced material manufacturing.

Biopolymers and bioinspired materials contribute to the construction of intricate hierarchical structures that exhibit advanced properties. The remarkable toughness and damage tolerance of such multilevel materials are conferred through the hierarchical assembly of their multiscale (i.e., atomistic to macroscale) components and architectures. Here, the functionality and mechanisms of biopolymers and bio-inspired materials at multilength scales are explored and summarized, focusing on biopolymer nanofibril configurations, biocompatible synthetic biopolymers, and bio-inspired composites. Their modeling methods with theoretical basis at multiple lengths and time scales are reviewed for biopolymer applications. Additionally, the exploration of artificial intelligence-powered methodologies is emphasized to realize improvements in these biopolymers from functionality, biodegradability, and sustainability to their characterization, fabrication process, and superior designs. Ultimately, a promising future for these versatile materials in the manufacturing of advanced materials across wider applications and greater lifecycle impacts is foreseen.

This work presents a synergistic strategy that utilizes bidentate chelating diethyldithiocarbamate as surface ligands for cadmium-free quantum dots (QDs), which enhances the ligand binding on the QD surface and improves stress dissipation under bending. Consequently, the resulting flexible devices exhibit peak external quantum efficiencies above 15% and retain over 90% of their initial performance after 5000 bending cycles.

Flexible light-emitting diodes utilizing environmentally friendly cadmium (Cd)-free quantum dots (QDs) hold immense potential for next-generation wearable integrated displays. However, their overall performance lags behind Cd-based counterparts, and less research focuses on the suitability of QD layers in flexible devices. Herein, it is observed that the traditional surface oleate ligands on QDs readily detach under device operation after cycling bending, leading to increased surface defects and accumulated tensile stress in QDs layers, further diminishing their photoluminescence and electroluminescence performance. Based on these insights, a synergetic regulation strategy is developed employing a short-chain bidentate chelating ligand, diethyldithiocarbamate (DDTC), to strengthen the binding of QDs with ligands, minimizing ligand detaching and consequently inhibiting the non-radiative recombination of QDs; Meanwhile, the short-chain DDTC also reduces the inter-dot spatial distance and decreases the Young's modulus in QDs films, effectively dissipating stress localization and retaining the film morphology upon bending. Consequently, the resulting flexible devices based on blue ZnSeTe/ZnSe/ZnS QDs and green/red InP/ZnSe/ZnS QDs demonstrate the peak external quantum efficiencies of above 15% and maintain over 90% after 5000 bending cycles, rivaling state-of-the-art Cd-based flexible devices.

A flexible ionic synaptic device is developed to replicate the brain's ion transport and ephaptic coupling mechanisms, enabling efficient energy consumption and complex connectivity. By using ions for signal transmission, the device achieves spatiotemporal signal integration, mimicking the computational capabilities of biological neural networks. This work advances the development of brain-like AI systems with enhanced connectivity and processing efficiency.

Neuromorphic devices are designed to replicate the energy-efficient information processing advantages found in biological neural networks by emulating the working mechanisms of neurons and synapses. However, most existing neuromorphic devices focus primarily on functionally mimicking biological synapses, with insufficient emphasis on ion transport mechanisms. This limitation makes it challenging to achieve the complexity and connectivity inherent in biological systems, such as ephaptic coupling. Here, an ionic biomimetic synaptic device based on a flexible ion-gel nanofiber network is proposed, which transmits information and enables ephaptic coupling through capacitance formation by ion transport with an extremely low energy consumption of just 6 femtojoules. The hysteretic ion transport behavior endows the device with synaptic-like memory effects, significantly enhancing the performance of the reservoir computing system for classifying the MNIST handwritten digit dataset and demonstrating high efficiency in edge learning. More importantly, the devices in an array establish communication connections, exhibiting global oscillatory behaviors similar to ephaptic coupling in biological neural networks. This connectivity enables the array to perform working memory tasks, paving the way for developing brain-like systems characterized by high complexity and vast connectivity.

A 570 meV emission shift is achieved through surface-enhanced Landau damping during phase transitions. In crystalline Sb₂Te₃, localized surface plasmons facilitate hot-electron injection, shifting the emission energy from 1.64 to 2.21 eV. This tunability is further enhanced by applying a DC voltage bias, making it suitable for integration with on-chip quantum photonic systems.

Tuning quantum emission to a specific wavelength at room temperature holds significant promise for enhancing secure quantum communication, particularly by aligning with the Fraunhofer lines in the solar spectrum. The integration of quantum emitters with phase-change materials enables emission wavelength modulation, especially when strong field enhancement is present. Antimony telluride (Sb2Te3) exhibits the potential to facilitate this functionality through its support of interband plasmonics and phase-change behavior. In this study, Sb₂Te₃ antennae are designed and fabricated to tune the emission energy of adjacent perovskite quantum dots (QDs) by over 570 meV. The underlying mechanism involves the localized surface plasmons (LSPs) on Sb₂Te₃ nanostructures, which exhibit a surface-enhanced Landau damping process that facilitates the decay of LSPs into electron-hole pairs. The generated hot electrons are then injected into perovskite QDs via the microscopic electron transport process, which can be triggered by the transition of Sb2Te3 from amorphous to a crystalline state, resulting in a significant emission energy shift from 1.64 to 2.21 eV. Furthermore, the emission energy of perovskite QDs on crystalline Sb₂Te₃ nanoantennae can be modulated through DC voltage bias, highlighting the potential for extensive wavelength tunability of quantum emitters integrated with electronic systems.

Three morphologies of spinel catalysts for the decomposition of polyethylene terephthalate (PET) are prepared by hydrothermal method. The optimization of morphology made a positive impact on PET conversion, yield of bis(2-hydroxyethyl) terephthalate (BHET), and photocatalytic performance. Catalyst with octahedral morphology has an optimum content of oxygen vacancies, which can work as active sites to promote PET degradation.

Thermocatalytic recycling of plastics is typically constrained by high energy input requirements, resulting in poor economic efficiency and necessitating the utilization of light power. Indeed, photothermal catalysis offers several advantages over traditional photocatalysis and enables more efficient use of light energy. In this study, unique octahedral spinel-structured cobalt manganese oxide (CoMn2O4) catalysts are prepared. CoMn2O4 acts as both a photothermal reagent and catalyst, demonstrating low light intensity requirements, high conversion rates, enhanced reactivity, and superior stability during polyethylene terephthalate (PET) glycolysis via photothermocatalysis. Oxygen vacancies created on CoMn2O4 facilitate PET glycolysis by providing reactive sites that promote nucleophilic addition and subsequent elimination reactions. The spinel structure of CoMn2O4 ensures high thermal stability, while the octahedral configuration enhances the optical absorption coefficient and photothermal conversion efficiency. Under identical conditions, the PET conversion efficiency of CoMn2O4 in photothermal catalysis is 3.1 times higher than under purely thermal conditions, while maintaining high selectivity for high-value monomers. This study presents a new catalyst design approach for highly efficient upcycling of plastics, highlighting its substantial potential in this field.

An in situ polymerization strategy is rationally proposed to synthesize cross-linked polymer solid-state electrolyte and polymer-encapsulated graphite cathode, which achieves intimate interface contact, dendrite free, flame retardancy, and confined volume expansion, enabling a solid-state aluminum-graphite battery with high-areal-capacity, high-safety, and long-lasting lifespan.

Nonaqueous rechargeable aluminum batteries (RABs) attract intense interest due to their low-cost, high-capacity, and high-safety using nonflammable chloroaluminate ionic liquid electrolytes (ILEs). However, Al dendrite growth, interface degradation, and corrosiveness remain challenges in these ILEs. Herein, an ultrastable solid-state aluminum battery (SAB) based on a cross-linked polymer solid-state electrolyte (PSE) and a PSE-encapsulated graphite (PG) cathode is constructed via an in situ polymerization strategy, which maintains battery safety and realizes a synergy of interface compatibility between PSE/PG and PSE/Al interfaces. The PSE has a high room temperature ionic conductivity of 4.15 × 10−3 S cm−1 and a low corrosiveness to Al anode, ensuring rapid and continuous transportation of chloroaluminate ions and homogeneous plating/stripping of metallic Al. In addition, the volume expansion of the PG cathode is almost negligible owing to the confinement effect of graphite within the cross-linked polymer skeleton. As a consequence, the assembled SAB demonstrates high areal capacity (0.67 mAh cm−2 at 0.1 mA cm−2), good rate performance, and impressive cycling stability (no capacity attenuation after 10 000 cycles). Such in situ polymerization strategy shows a broader promise for the development of safe and stable RABs in energy storage applications.

The coupling strategies between multi-physical fields and photoelectric effects in 2D material-based photodetectors are systematically summarized in this review. It highlights the effects of their synergistic mechanisms on energy band structures, carrier dynamics, and device performance. The article concludes with future research directions, providing a roadmap for developing high-performance intelligent optoelectronic devices.

2D materials possess exceptional carrier transport properties and mechanical stability despite their ultrathin nature. In this context, the coupling between polarization fields and photoelectric fields has been proposed to modulate the physical properties of 2D materials, including energy band structure, carrier mobility, as well as the dynamic processes of photoinduced carriers. These strategies have led to significant improvements in the performance, functionality, and integration density of 2D materials -based photodetectors. The present review introduces the coupling of photoelectric field with four fundamental polarization fields, delivered from dielectric, piezoelectric, pyroelectric, and ferroelectric effects, focusing on their synergistic coupling mechanisms, distinctive properties, and technological merits in advanced photodetection applications. More importantly, it sheds light on the new path of material synthesis and novel structure design to improve the efficiency of the coupling strategies in photodetectors. Then, research advances on the synergy of multi-polarization effects and photoelectric effect in the domain of bionic photodetectors are highlighted. Finally, the review outlines the future research perspectives of coupling strategies in 2D materials-based photodetectors and proposes potential solutions to address the challenges issues of this area. This comprehensive overview will guide futural fundamental and applied research that capitalizes on coupling strategies for sensitive and intelligent photodetection.

The ultraviolet laser irradiation is used to cut off the outer shell of double-walled carbon nanotubes (DWCNTs). A velocity-dependent intershell friction occurs between the outer and inner shells. This friction results from dynamic localized commensurate contacts. The friction-induced intershell locking enhances the dynamic strength of DWCNTs to over 90 GPa, indicating that DWCNTs possess exceptional resistance to high-velocity impacts.

Low-dimensional ultra-strong nanomaterials have attracted great anticipation for applications under extreme dynamic conditions. A photocatalytic method is developed to selectively cut off the outer shell of double-walled carbon nanotubes (DWCNTs), achieving non-contact measurement of intershell friction with both high temporal and spatial resolutions at high sliding velocities under optical microscope. The intershell friction linearly increases with the sliding velocity, with a slope related to intershell distance and chirality of DWCNTs. The maximum measured friction reaches 194.1 ± 7.3 nN at a sliding velocity of 977 mm s−1, a value comparable to the tensile force (≈450 nN) for breaking the outer shell. Molecular dynamics simulations indicate that the velocity-dependent intershell friction is related to dynamic localized commensurate contacts. The friction-induced “intershell locking” enhances the effective dynamic strength of DWCNTs from 64.8 ± 3.4 GPa to 90.1 ± 4.0 GPa at a tensile strain rate of 3300 s−1. This study reveals anomalous friction mechanisms at nanoscale and demonstrates promising application of DWCNTs as ultra-strong materials.

By proposing a single-cell order-decoupling method and simultaneously manipulating four-dimensional optical parameters (Wavelength, Wavevector Direction, Polarization, and Diffraction Order), a meta-optics storage system accomplishes multidimensional optical encryption. This system achieves up to sixteen-channel multidimensional encrypted holographic images with high quality and exponentially raises the threshold of brute-force decoding, and thus remarkably enhances information security in optical storage.

Recent advancements in multidimensional multiplexing have paved the way for meta-optics encryption to be a viable solution to next-generation information storage and encryption security. However, challenges persist in increasing simultaneously modulated dimensions while minimizing structural complexity. Here, a novel single-cell order-decoupling method is proposed for the realization of a multidimensional encrypted meta-optics storage system. By analyzing the mathematic relationships between the phases of different diffraction orders, the detour phase structure is optimized to achieve independent encoding freedom for multiple orders. The proposed multidimensional encrypted meta-optics successfully realize the concurrent modulation of four optical dimensions: i) Wavelength, ii) Wavevector Direction, iii) Polarization, and iv) Diffraction Order. The system achieves up to sixteen-channel meta-holograms with low crosstalk and exponentially raises the threshold of brute-force decoding and thus remarkably enhances the information security in optical storage. It envisioned that the on-chip metasurface-based multidimensional encrypted strategy for augmented reality display functionalities presents promising applications in optical encryption/storage, anti-counterfeiting, and multifunctional photonics integrated circuits.

When water drops slide on hydrophobic surfaces, they spontaneously leave behind negative charges along their path, resulting in the drops becoming positively charged. Here, it is shown that this phenomenon, known as slide electrification, influences the deposition of charged dissolved molecules. Using charged fluorophores and biomolecules, a preferential deposition of cations along the drop's trail is demonstrated, following the charge distribution pattern.

It has been discovered during the last decade that when water drops slide on hydrophobic surfaces, they spontaneously leave negative charges along the drop path. The drops become positively charged with a potential of 1 kV. This process, called slide electrification, influences drop motion and alters contact angles. Here, a third effect of slide electrification is demonstrated: the preferential deposition of dissolved solutes with positive charges. To illustrate this, water drops containing dissolved charged fluorophore ions are allowed to slide down a tilted hydrophobic surface, and their track is imaged. Two perylene derivatives are applied as fluorophores, one chromophore carrying positive charges, PDI+, and one carrying negative charges, PDI─. PDI+ is deposited at a concentration as low as 0.5 µm. In contrast, PDI─ is only deposited above 5 µm. Experiments using grounded drops or a hydrophobic coating on a conducting substrate indicate that the electric field generated from the negative surface charges behind the drop causes a preferential deposition of the dissolved ions near the interface. This hypothesis also agrees with Kelvin probe measurements. Complex biomolecules deposition e.g. DNA can be also affected by this. These findings contribute to a better understanding of mass transfer processes at interfaces.

Bimetallic nitrides supported RuNi alloy (RuNi/ZrNiNx) epitaxial heterostructure as a bifunctional catalyst achieves highly stable and active hydrogen and oxygen evolution at ampere-scale current densities. Charge redistribution induced high-valence Zr promotes the water dissociation, electron-deficient Ru facilitates H desorption, and the hollow site of tri-coordinated Ni in NiNx that is adjacent to Zr atom favors the energetically favorable O2 production.

Alkaline water electrolysis represents a pivotal technology for green hydrogen production yet faces critical challenges including limited current density and high energy input. Herein, a heterostructured bimetallic nitrides supported RuNi alloy (RuNi/ZrNiNx) is developed through in situ epitaxial growth under ammonolysis, achieving exceptional bifunctional activity and durability for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in 1 m KOH electrolyte. The RuNi/ZrNiNx exhibits a HER current density of −2 A cm−2 at an overpotential of 392.8 mV, maintaining initial overpotential after 1000 h continuous electrolysis at −500 mA cm−2. For OER, it delivers a current density of 2 A cm−2 at 1.822 V versus RHE, and sustains stable operation for 705 h at 500 mA cm−2. Experimental and theoretical studies unveil that the charge redistribution-induced high-valence Zr centers effectively polarize H─O bonds and promote water dissociation, and the electron-deficient interface Ru sites optimize hydrogen desorption kinetics. Dynamic OH spillovers from Zr sites to the adjacent tri-coordinated Ni hollow sites in NiNx promote rapid *OH intermediate desorption and active site regeneration. Notably, the tri-coordinated Ni hollow sites in NiNx proximal to Zr atoms exhibit tailored adsorption strength for oxo-intermediates, enabling a more energetically favorable pathway for O2 production.

Upconversion nanoparticle-covalent organic framework core–shell particles provide enhanced contrast for optoacoustic imaging by leveraging the optical absorption of upconversion luminescence within the covalent organic framework matrix. Beyond their role as contrast agents, these particles enable customizable therapeutic agent loading and release, as well as magnetic microrobotic steering within vascular environments.

Despite the development of various medical imaging contrast agents, integrating contrast signal generation with therapeutic and microrobotic functions remains challenging without complicated fabrication processes. In this study, upconversion nanoparticle-covalent organic framework (UCNP-COF) core–shell sub-micron particles are developed that function as therapeutic microrobots trackable with multi-spectral optoacoustic tomography (MSOT) imaging and can be loaded with desired therapeutic molecular agents in a customizable manner. The mechanism of optoacoustic signal generation in UCNP-COF particles is attributed to the quenching of upconversion luminescence emitted by the UCNPs, which is absorbed by the encapsulating COF and subsequently converted into acoustic waves. Unlike other microparticulate agents previously imaged with MSOT, UCNP-COF particles do not pose concerns about their stability and biocompatibility. Simultaneously, the mesoporous texture of the COF provides a large surface area, allowing for the efficient loading of various drug molecules, which can be released at target sites. Furthermore, the magnetic UCNP-COF Janus particles can be magnetically navigated through in vivo vasculature while being visualized in real-time with volumetric MSOT. This study proposes an approach to design photonic materials with multifunctionality, enabling high-performance medical imaging, drug delivery, and microrobotic manipulation toward their future potential clinical use.

A strongly coupled multisite anode electrocatalyst with cluster-scale ruthenium-tungsten oxide (Ru-WOx) interface is developed for alkaline anion exchange membrane fuel cells (AEMFCs), which could simultaneously achieve high coverage of hydroxyl (OHad) and hydrogen (Had) at Ru and WOx domains, respectively. The AEMFC delivers a high peak power density of 1.36 W cm−2 with a low anode catalyst loading of 0.05 mgRu cm−2 and outstanding durability.

Ruthenium (Ru) is a more cost-effective alternative to platinum anode catalysts for alkaline anion-exchange membrane fuel cells (AEMFCs), but suffers from severe competitive adsorption of hydrogen (Had) and hydroxyl (OHad). To address this concern, a strongly coupled multisite electrocatalyst with highly active cluster-scale ruthenium-tungsten oxide (Ru-WOx) interface, which could eliminate the competitive adsorption phenomenon and achieve high coverage of OHad and Had at Ru and WOx domains, respectively, is designed. The experimental and theoretical results demonstrate that WOx domain functions as a proton sponge to perpetually accommodate the activated hydrogen species that spillover from the adjacent Ru domain, and the resulting WO-Had species are readily coupled with Ru-OHad at the heterointerface to finish the hydrogen oxidation reaction with faster kinetics via the thermodynamically favorable Tafel-Volmer mechanism. The AEMFC delivers a high peak power density of 1.36 W cm−2 with a low anode catalyst loading of 0.05 mgRu cm−2 and outstanding durability (negligible voltage decay over 80-h operation at 500 mA cm−2). This work offers completely new insights into understanding the alkaline HOR mechanism and designing advanced anode catalysts for AEMFCs.

The heart organoid model exhibits the acidic microenvironment characteristic of myocardial infarction, which emerges as a pivotal force propelling the movement of micro-robots. These micro-robots, administered through microneedles, can penetrate deep into the tissue, effectively delivering therapeutic payloads to facilitate heart repair.

Post-myocardial infarction (MI), the rapid decrease in pH triggers myocardial cell acidosis, which compromises the therapeutic efficacy of exosomes in MI. The groundbreaking research in the human cardiac organoid MI model suggests that exosomes, when paired with pH adjustment, dramatically reduce cardiomyocyte mortality while maintaining their proliferative potential, underscoring the importance of pH regulation in myocardial preservation. Micro-robot mounted micro-needle (MN) patch is thus proposed, targeting MI-acidic microenvironmet, to deliver exosomes into deep injured tissue. Upon injection, the patch base releases VEGF-laden nanoparticles adhering to the infarcted myocardium. The smart patch is found not only 3D reconstructs the vascular network in MI regions but also effectively saves cardiomyocytes in rats. Furthermore, the minimally invasive delivery of MN patches are also verified to hearts of rabbits and pigs via thoracoscopic surgery underscores. These findings suggest that precise regulation of the microenvironment is a key to improving treatment outcomes.

This study proposes tribenzyl organic cation carried multidentate X-type Lewis soft base to enhance adhesion and passivate defects simultaneously, aiming to achieve foldable and efficient perovskite nanocrystal-based light-emitting diodes. The resulting pure red F-PeLEDs exhibit a recorded high EQE of 16.2% and robust mechanical properties to endure 5000 folding cycles with small radius of 1 mm.

Lead-halide perovskite nanocrystals (PNCs) exhibit significant potential for advancing foldable perovskite light-emitting diodes (F-PLEDs) due to their discrete crystalline morphology, bright emission across an extensive color gamut, and remarkable color purity; however, their progression remains in the early stages with the concerns of inadequate performance and mechanical instability. This study proposes a ligand strategy employing tribenzyl organic cation (tribenzylamine, TBA) carried multidentate X-type Lewis soft base (sodium acid pyrophosphate, SAPP) to address the challenges above simultaneously. Specifically, the use of multibranched aromatic ligands considerably improved the adhesion force between PNCs and adjacent layers, enhancing mechanical stability during folding, while the control sample shows deleterious cracks. Additionally, TBA-SAPP ligands effectively eliminate the defects in PNC film, yielding exceptional photoluminescence properties with a near-unity quantum yield. Consequently, the multifunctional ligands improved F-PLEDs to achieve a record-high external quantum efficiency (EQE) of 16.2% compared to the previously reported pure-red flexible PLEDs and display substantially improved spectral and operational stability. Equally important, these devices demonstrate robust mechanical properties, enduring a small folding radius of 1 mm for 5000 cycles. This ligand strategy is anticipated to inspire relevant research in PNCs and promote the realization of highly efficient and mechanically stable F-PLEDs.

The origin of oxygen framework stability is studied by integrating high covalent element Mo into the bulk and surface of ultra-high nickel cathode materials through a one-step method. Mo with strong covalency can suppress Li/Ni antisite defects and reduce Li-O-Li configurations, thus suppressing irreversible phase transition and stabilizing the oxygen framework structure at high voltage.

Ultra-high nickel layered oxides are recognized as promising cathode candidates for high-energy-density lithium-ion batteries due to their enhanced overall capacity and elevated operating voltage. However, the interlayer sliding of transition metal-oxygen octahedra (TMO6) and the instability of lattice oxygen at high voltages for ultra-high nickel oxide cathodes pose significant challenges to their development. Herein, the origin of oxygen framework stability is investigated by incorporating high-covalent element Mo in both bulk and surface using a one-step integrated method for ultra-high nickel cathode material LiNi0.92Co0.08O2. It is revealed that apart from the isolation and protection effect of the Mo-enriched surface layer, the suppression of Li/Ni antisite defects by Mo6+ with strong covalency in the bulk plays a critical role in reducing the configurations of the activated anionic redox reaction and stabilizing the lattice oxygen and oxygen framework structure. Benefiting from this, the reversibility of anionic redox reaction and the stability of oxygen framework is significantly enhanced, enabling more oxidized oxygen to exist in the form of oxygen dimer ions O2n−$O_2^{n - }$ rather than being lost as gaseous O2. Consequently, the modified ultra-high nickel material demonstrates improved diffusion kinetics and optimized electrochemical performance at high voltage.

Acid etching assisted direct upcycling strategy that selectively removals rock-salt phases on the surface of highly degraded LiNi0.5Co0.2Mn0.3O2 and dissociating polycrystalline structure to single crystals simultaneously, facilitating direct repair of its composition and structure via simple solid-state sintering. The regenerated LiNi0.5Co0.2Mn0.3O2 exhibits comparable capacity and more excellent electrochemical stability to commercialized ones.

Direct recycling of cathode materials has attracted phenomenal attention due to its economic and eco-friendly advantages. However, existing direct recycling technologies are difficult to apply to highly degraded layered materials as the accumulation of thick rock-salt phases on their surfaces not only blocks lithiation channels but also is thermodynamically difficult to transform into layered phases. Here, a surface engineering-assisted direct upcycling strategy that reactivates the lithium diffusion channels at the highly degraded cathode surfaces using acid etching explored. Acid can selectively remove the electrochemically inert rock-salt phases on the surface while simultaneously dissociating the degraded polycrystalline structure to single crystals, thereby reducing the thermodynamic barrier of the relithiation process and enhancing the stability of the regenerated cathode. This strategy can restore the capacity of highly degraded LiNi0.5Co0.2Mn0.3O2 from 59.7 to 165.4 mAh g−1, comparable to that of commercialized ones. The regenerated cathode also exhibits excellent electrochemical stability with a capacity retention of 80.1% at 1 C after 500 cycles within 3.0–4.2 V (vs graphite) in pouch-type full cells. In addition, the generality of this strategy has also been validated on Ni-rich layered materials and LiCoO2. This work presents a promising approach for direct recycling of highly degraded cathode materials.

A novel 3D printing method enables the fabrication of materials with precisely controlled mechanical properties at nanoscale resolution. A volume-conserving photoresist combined with the free and open-source software, OpenScribe, achieves mechanical transitions over 770 nanometers - representing a 130-fold improvement over existing approaches. This advancement enables the creation of complex materials with unprecedented control over local elasticity.

Fabrication methods that synthesize materials with higher precision and complexity at ever smaller scales are rapidly developing. Despite such advances, generating complex 3D materials with controlled mechanical properties at the nanoscale remains challenging. Exerting precise control over mechanical properties at the nanoscale would enable material strengths near theoretical maxima, and the replication of natural structures with hitherto unattainable strength-to-weight ratios. Here, a method for fabricating materials with nanovoxelated elastic moduli by employing a volume-conserving photoresist composed of a copolymer hydrogel, along with OpenScribe, an open-source software that enables the precise programming of material mechanics, is presented. Combining these, a material composed of periodic unit cells featuring heteromechanically tessellated soft-stiff structures, achieving a mechanical transition over an order-of-magnitude change in elastic modulus within 770 nm, a 130-fold improvement on previous reports, is demonstrated. This work critically advances material design and opens new avenues for fabricating materials with specifically tailored properties and functionalities through unparalleled control over nanoscale mechanics.

A novel non-fullerene acceptor, BFDO-4F, is integrated into organic photodetectors (OPDs) to enable electron trapping. The resulting devices exhibit dual-mode functionality, with bias-switchable operation between photovoltaic (PV) and photomultiplication (PM) modes. An on-chip module is demonstrated, where the PV section supplies bias for the PM section achieving self-powered amplifier-free system, highlighting the potential for multifunctional OPDs in advanced optoelectronic applications.

Photomultiplication-type organic photodetectors (PM-OPDs) provide for signal amplification, ideal for detecting faint light, and simplifying detection systems. However, current designs often suffer from slow response speed and elevated dark current. Conversely, photovoltaic-type organic photodetectors (PV-OPDs) provide fast response and high specific detectivity (D *) but have limited photoresponse. This study presents the synthesis and incorporation of a non-fullerene acceptor, BFDO-4F, into the active layer to introduce trap states for capturing photogenerated electrons. The resulting device exhibits dual-mode characteristic and is bias-switchable between PV and PM-modes. In PV-mode, the OPDs achieve high D * of 1.92 × 10¹2 Jones and a response time of 2.83/4.43 µs. In PM-mode, the OPDs exhibit exceptional external quantum efficiency (EQE) up to 3484% and a D * of up to 1.13 × 10¹2 Jones. An on-chip self-powered module with PV-mode pixels driving a PM-mode pixel is demonstrated, yielding a photocurrent approximately five times higher than the reference device. This approach paves the way for developing multifunctional bias-switchable dual-mode on-chip OPDs, suitable for various applications.