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

Atomic manufacturing is a guideline for researchers to precisely synthesize materials, customize their properties, and apply them into advanced applications in demand. Atomic manufacturing has the ability to visualize substances at the atomic level, while manipulating them atom by atom, inducing and promoting chemical reactions, and ultimately obtaining products with specific atomic structures.

The quest for cutting-edge materials and devices has necessitated elevated demands for manufacturing methodologies. Atomic manufacturing involves the meticulous design and fabrication of materials and devices at the atomic level, a process that has been facilitated by advancements in comprehending and manipulating atomic behavior. The attainment of atomic manufacturing is dependent on the capacity to precisely manipulate atoms, directing their reactions at will. In this review, five methodologies of atomic fabrication encompassing atomic manipulation, atomic programming, atomic epitaxy, atomic confinement, and atomic assembly are elucidated. Based on this, the utilization of atomic manufacturing in the most advanced domains including energy conversion, energy storage, quantum information technology, and optoelectronic devices is elucidated. Finally, the current challenges and outlook on the forthcoming advancement of atomic manufacturing are presented.

2D magnets provide diverse magnetic orders for spins to be aligned, including intralayer ferromagnetism, antiferromagnetism, and interlayer (A-type) antiferromagnetism, which allow the spins to precess in a wide range of frequency from GHz to X-ray. By interacting with the given wavelength of light/electromagnetic wave, the spins can be excited (written) and detected (read), realizing different types of opto-spintronic devices and functions.

Since the emergence of 2D magnets in 2017, the diversity of these materials has greatly expanded. Their 2D nature (atomic-scale thickness) endows these magnets with strong magnetic anisotropy, layer-dependent and switchable magnetic order, and quantum-confined quasiparticles, which distinguish them from conventional 3D magnetic materials. Moreover, the 2D geometry facilitates light incidence for opto-spintronic applications and potential on-chip integration. In analogy to optoelectronics based on optical–electronic interactions, opto-spintronics use light-spin interactions to process spin information stored in the solid state. In this review, opto-spintronics is divided into three types with respect to the wavelengths of radiation interacting with 2D magnets: 1) GHz (microwave) to THz (mid-infrared), 2) visible, and 3) UV to X-rays. It is focused on the recent research advancements on the newly discovered mechanisms of light-spin interactions in 2D magnets and introduces the potential design of novel opto-spintronic applications based on these interactions.

A monolayer high-entropy layered hydroxide (HELH) frame is prepared by in situ conversion from Zn,Co-ZIF under a mild environment. The HELH with tailored geometric structure provides a guideline for designing advanced electrocatalysts. It also provides a new insight into the field of fine regulation of high-entropy material structure.

High-entropy materials with tailored geometric and elemental compositions provide a guideline for designing advanced electrocatalysts. Layered double hydroxides (LDHs) are the most efficient oxygen evolution reaction (OER) catalyst. However, due to the huge difference in ionic solubility product, an extremely strong alkali environment is necessary to prepare high-entropy layered hydroxides (HELHs), which results in an uncontrollable structure, poor stability, and scarce active sites. Here, a universal synthesis of monolayer HELH frame in a mild environment is presented, regardless of the solubility product limit. Mild reaction conditions allow this study to precisely control the fine structure and elemental composition of the final product. Consequently, the surface area of the HELHs is up to 380.5 m2 g−1. The current density of 100 mA cm−2 is achieved in 1 m KOH at an overpotential of 259 mV, and, after 1000 h operation at the current density of 20 mA cm−2, the catalytic performance shows no obvious deterioration. The high-entropy engineering and fine nanostructure control open opportunities to solve the problems of low intrinsic activity, very few active sites, instability, and low conductance during OER for LDH catalysts.

A series of AIEgen-based covalent organic frameworks are constructed with a unique “one stone, two birds” functionality, which is not only efficient in directly modulating the function and neural activity of stellate ganglion (SG) through local hyperthermia therapy, but also further inducing browning of white fat and ameliorating the neuroinflammation of peri-SG, favorable for inhibiting malignant ventricular arrhythmias.

The engineering of aggregation-induced emission luminogens (AIEgen) based covalent organic frameworks (COFs), TDTA-COF, BTDTA-COF, and BTDBETA-COF are reported, as hyperthermia agents for inhibiting the occurrence of malignant ventricular arrhythmias (VAs). These AIE COFs exhibit dual functionality, as they not only directly modulate the function and neural activity of stellate ganglion (SG) through local hyperthermia therapy (LHT) but also induce the browning of white fat and improve the neuroinflammation peri-SG microenvironment, which is favorable for inhibiting ischemia-induced VAs. In vivo studies have confirmed that BTDBETA-COF-mediated LHT enhances thermogenesis and browning-related gene expression, thereby serving a synergistic role in combating VAs. Transcriptome analysis of peri-SG adipose tissue reveals a substantial downregulation of inflammatory cytokines, highlighting the potency of BTDBETA-COF-mediated LHT in ameliorating the neuroinflammation peri-SG microenvironment and offering myocardial and arrhythmia protection. The work on AIE COF-based hyperthermia agent for VAs inhibition provides a new avenue for mitigating cardiac sympathetic nerve hyperactivity.

Most of the infectious diseases in the oral cavity are based on disturbances in the bacterial-cellular microenvironment. In this work, a microenvironment-targeted drug delivery nanoparticle is prepared to inhibit bacterial adhesion to surfaces, modulate macrophage polarization, and produce photodynamic and photothermal effects. It performs antibacterial, anti-biofilm, and anti-inflammation effects to achieve the treatment and prevention for typical biofilm-induced oral diseases.

The oral cavity comprises an environment full of microorganisms. Dysregulation of this microbial-cellular microenvironment will lead to a series of oral diseases, such as implant-associated infection caused by Staphylococcus aureus (S. aureus) biofilms and periodontitis initiated by Streptococcus oralis (S. oralis). In this study, a liposome-encapsulated indocyanine green (ICG) and rapamycin drug-delivery nanoparticle (ICG-rapamycin) is designed to treat and prevent two typical biofilm-induced oral diseases by regulating the microbial-cellular microenvironment. ICG-rapamycin elevates the reactive oxygen species (ROS) and temperature levels to facilitate photodynamic and photothermal mechanisms under near-infrared (NIR) laser irradiation for anti-bacteria. In addition, it prevents biofilm formation by promoting bacterial motility with increasing the ATP levels. The nanoparticles modulate the microbial-cellular interaction to reduce cellular inflammation and enhance bacterial clearance, which includes promoting the M2 polarization of macrophages, upregulating the anti-inflammatory factor TGF-β, and enhancing the bacterial phagocytosis of macrophages. Based on these findings, ICG-rapamycin is applied to implant-infected and periodontitis animal models to confirm the effects in vivo. This study demonstrates that ICG-rapamycin can treat and prevent biofilm-induced oral diseases by regulating the microbial-cellular microenvironment, thus providing a promising strategy for future clinical applications.

Hollow-structured mesoporous carbons with ultrahigh surface area, large pore volume and heteroatom doping are synthesized by a versatile and general silanol-assisted surface-casting method. The materials display remarkable electrochemical performance for lithium-ion batteries. The studies reveal that strong interactions between the organic molecules and the silanol-rich surface of the silica template are crucial.

Nanoporous carbons are very attractive for various applications including energy storage. Templating methods with assembled amphiphilic molecules or porous inorganic templates are typically used for the synthesis. Amongst the different members of this family, CMK-5-like structures that are constructed to consist of sub-10 nm amorphous carbon nanotubes and ultrahigh specific surface area due to their thin pore walls, have the best properties in various respects. However, the fabrication of such hollow-structured mesoporous carbons entails elaborately tailoring the surface properties of the template pore walls and selecting specific carbon precursors. Thus, very limited cases are successful. Herein, a versatile and general silanol-assisted surface-casting method to create hollow-structured mesoporous carbons and heteroatom-doped derivatives with numerous organic molecules (e.g., furfuryl alcohol, resol, 2-thiophene methanol, dopamine, tyrosine) and different structural templates is reported. These carbon materials exhibit ultrahigh surface area (2400 m2 g−1), large pore volume (4.0 cm3 g−1), as well as satisfactory lithium-storage capacity (1460 mAh g−1 at 0.1 A g−1), excellent rate capability (320 mAh g−1 at 5 A g−1), and very outstanding cycling performance (2000 cycles at 5 A g−1).

The retention of individual gold nanoparticles on a substrate, enabling single-nanoparticle nanomachining, is enabled via a simple and versatile strategy. This method involves three steps: the formation of a carbon protective layer on individual nanoparticle via electron-beam irradiation, selective removal of unprotected nanoparticles using a corrosive agent, and subsequent elimination of the carbon layer. This enables the fabrication of a single micrometer-long uniform through nanochannel in the silicon wafer, which can be employed for nanopore sensing and shape-based nanoparticle distinguishing.

The structure of nanomaterials and nanodevices determines their functionality and applications. A single uniform nanochannel with a high aspect ratio is an attractive structure due to its unique rigid structures, easy preparation, and diverse pore structures and it holds significant promising importance in fields such as nanopore sensing and nanomanufacturing. Although the metal-nanoparticle-assistant silicon etching technique can produce uniform nanochannels, however, the fabrication of single through nanochannels remains a challenge thus far. A simple and versatile strategy is developed that allows for the retention of individual gold nanoparticle on a substrate, enabling single-nanoparticle nanomachining. This method involves three steps: the formation of a carbon protective layer on individual nanoparticles via electron-beam irradiation, selective removal of unprotected nanoparticles using a corrosive agent, and subsequent elimination of the carbon layer. This enables the fabrication of a single submillimeter-long uniform through nanochannel in the silicon wafer, which can be employed for nanopore sensing and shape-based nanoparticle distinguishing. The developed method can also facilitate single-nanoparticle studies and nanomachining for a broad application in materials science, electronics, micro/nano-optics, and catalysis.

The ultrathin van der Waals (vdW) LaOCl is synthesized by controlling the growth kinetics. Due to the considerable dielectric properties of LaOCl and its dangling-bond-free surface, the MoS2 field-effect transistor (FET) with vdW LaOCl dielectric exhibits ultralow hysteresis. LaOCl possesses the tremendous potential to act as an ideal gate dielectric for two-dimensional FETs.

Downsizing silicon-based transistors can result in lower power consumption, faster speeds, and greater computational capacity, although it is accompanied by the appearance of short-channel effects. The integration of high-mobility 2D semiconductor channels with ultrathin high dielectric constant (high-κ) dielectric in transistors is expected to suppress the effect. Nevertheless, the absence of a high-κ dielectric layer featuring an atomically smooth surface devoid of dangling bonds poses a significant obstacle in the advancement of 2D electronics. Here, ultrathin van der Waals (vdW) lanthanum oxychloride (LaOCl) dielectrics are successfully synthesized by precisely controlling the growth kinetics. These dielectrics demonstrate an impressive high-κ value of 10.8 and exhibit a remarkable breakdown field strength (E bd) exceeding 10 MV cm−1. Remarkably, the conventional molybdenum disulfide (MoS2) field-effect transistor (FET) featuring a dielectric made of LaOCl showcases an almost negligible hysteresis when compared to FETs employing alternative gate dielectrics. This can be attributed to the flawlessly formed vdW interface and excellent compatibility established between LaOCl and MoS2. These findings will motivate the further exploration of rare-earth oxychlorides and the development of more-than-Moore nanoelectronic devices.

The “quasi-solid-state reaction” mechanism can enable the redox reaction of sulfur to proceed in a solid-phase conversion manner in liquid electrolytes without the generation and dissolution of polysulfide intermediates at cycling, and therefore is a promising approach to develop high-capacity and cycle-stable sulfur cathodes for practical lithium–sulfur (Li–S) batteries.

Lithium–sulfur (Li–S) batteries have been investigated intensively as a post-Li-ion technology in the past decade; however, their realizable energy density and cycling performance are still far from satisfaction for commercial development. Although many extremely high-capacity and cycle-stable S cathodes and Li anodes are reported in literature, their use for practical Li–S batteries remains challenging due to the huge gap between the laboratory research and industrial applications. The laboratory research is usually conducted by use of a thin-film electrode with a low sulfur loading and high electrolyte/sulfur (E/S) ratios, while the practical batteries require a thick/high sulfur loading cathode and a low E/S ratio to achieve a desired energy density. To make this clear, the inherent problems of dissolution/deposition mechanism of conventional sulfur cathodes are analyzed from the viewpoint of polarization theory of porous electrode after a brief overview of the recent research progress on sulfur cathodes of Li–S batteries, and the possible strategies for building an electrochemically stable sulfur cathode are discussed for practically viable Li–S batteries from the authors’ own understandings.

An overview of interface engineering strategies to overcome the limitation of the Debye screening effect for the achievement of high-performance FET-based electronic devices is proposed, and their applications in biological environment analysis are systematically summarized.

Promising advances in molecular medicine have promoted the urgent requirement for reliable and sensitive diagnostic tools. Electronic biosensing devices based on field-effect transistors (FETs) exhibit a wide range of benefits, including rapid and label-free detection, high sensitivity, easy operation, and capability of integration, possessing significant potential for application in disease screening and health monitoring. In this perspective, the tremendous efforts and achievements in the development of high-performance FET biosensors in the past decade are summarized, with emphasis on the interface engineering of FET-based electrical platforms for biomolecule identification. First, an overview of engineering strategies for interface modulation and recognition element design is discussed in detail. For a further step, the applications of FET-based electrical devices for in vitro detection and real-time monitoring in biological systems are comprehensively reviewed. Finally, the key opportunities and challenges of FET-based electronic devices in biosensing are discussed. It is anticipated that a comprehensive understanding of interface engineering strategies in FET biosensors will inspire additional techniques for developing highly sensitive, specific, and stable FET biosensors as well as emerging designs for next-generation biosensing electronics.

This perspective focuses on the latest progresses in material sciences for solving the problems related to the catalyst/ionomer interface in PEMFCs, with particular emphasis put on the effects of materials structures and intermolecular interactions. The content covers catalysts, ionomers, and additives. Based on molecule-level understanding, the challenges for the application of established materials and opportunities to broaden the material library are proposed.

The most critical challenge for the large-scale commercialization of proton exchange membrane fuel cells (PEMFCs), one of the primary hydrogen energy technologies, is to achieve decent output performance with low usage of platinum (Pt). Currently, the performance of PEMFCs is largely limited by two issues at the catalyst/ionomer interface, specifically, the poisoning of active sites of Pt by sulfonate groups and the extremely sluggish local oxygen transport toward Pt. In the past few years, emerging strategies are derived to tackle these interface problems through materials optimization and innovation. This perspective summarizes the latest advances in this regard, and in the meantime unveils the molecule-level mechanisms behind the materials modulation of interfacial structures. This paper starts with a brief introduction of processes and structures of catalyst/ionomer interfaces, which is followed by a detailed review of progresses in key materials toward interface optimization, including catalysts, ionomers, and additives, with particular emphasis on the role of materials structure in regulating the intermolecular interactions. Finally, the challenges for the application of the established materials and research directions to broaden the material library are highlighted.

A comprehensive set of key performance indicators is proposed to address the limitations of current evaluation methods for the processability of organic photovoltaic materials, aiming to guide academic research and enhance industrial processability.

The evolution of organic semiconductors for organic photovoltaics (OPVs) has resulted in unforeseen outcomes. This has provided substitute choices of photoactive layer materials, which effectively convert sunlight into electricity. Recently developed OPV materials have narrowed down the gaps in efficiency, stability, and cost in devices. Records now show power conversion efficiency in single-junction devices closing to 20%. Despite this, there is still a gap between the currently developed OPV materials and those that meet the requirements of practical applications, especially the solution processability issue widely concerned in the field of OPVs. Based on the general rule that structure determines properties, methodologies to enhance the processability of OPV materials are reviewed and explored from the perspective of material design and views on the further development of processable OPV materials are presented. Considering the current dilemma that the existing evaluation indicators cannot reflect the industrial processability of OPV materials, a more complete set of key performance indicators are proposed for their processability considerations. The purpose of this perspective is to raise awareness of the boundary conditions that exist in industrial OPV manufacturing and to provide guidance for academic research that aspires to contribute to technological advancements.

The research of non-Hermitian physics is in the ascendant and has brought new opportunities for the development of topological metamaterials. This perspective reviews the recent advances in non-Hermitian topological phononic metamaterials for acoustic wave and mechanical structures. New configurations and mechanisms for skin effect in high-dimensional non-Hermitian systems and non-Hermitian effect for elastic wave metamaterials are worthy of further exploration.

Non-Hermitian (NH) physics describes novel phenomena in open systems that allow generally complex spectra. Introducing NH physics into topological metamaterials, which permits explorations of topological wave phenomena in artificially designed structures, not only enables the experimental verification of exotic NH phenomena in these flexible platforms, but also enriches the manipulation of wave propagation beyond the Hermitian cases. Here, a perspective on the advances in the research of NH topological phononic metamaterials is presented, which covers the exceptional points and their topological geometries, the skin effect related to the topology of complex spectra, the interplay of NH effects and topological states in phononic metamaterials, etc.

The burgeoning field of twistronics has been ignited by the straightforward manipulation of interlayer twist between van der Waals layered materials. This perspective highlights the in situ twisting techniques and the underlying superlubricity mechanism, and exemplifies new promising opportunities arising from the intersection of the fields of twistronics, nanotribology, and micro/nano-electro-mechanical systems (MEMS/NEMS), etc.

Twistronics, an emerging field focused on exploring the unique electrical properties induced by twist interface in graphene multilayers, has garnered significant attention in recent years. The general manipulation of twist angle depends on the assembly of van der Waals (vdW) layered materials, which has led to the discovery of unconventional superconductivity, ferroelectricity, and nonlinear optics, thereby expanding the realm of twistronics. Recently, in situ tuning of interlayer conductivity in vdW layered materials has been achieved based on scanning probe microscope. In this Perspective, the advancements in in situ twistronics are focused on by reviewing the state-of-the-art in situ manipulating technology, discussing the underlying mechanism based on the concept of structural superlubricity, and exploiting the real-time twistronic tests under scanning electron microscope (SEM). It is shown that the real-time manipulation under SEM allows for visualizing and monitoring the interface status during in situ twistronic testing. By harnessing the unique tribological properties of vdW layered materials, this novel platform not only enhances the fabrication of twistronic devices but also facilitates the fundamental understanding of interface phenomena in vdW layered materials. Moreover, this platform holds great promise for the application of twistronic-mechanical systems, providing avenues for the integration of twistronics into various mechanical frameworks.

This study utilizes solution-phase microwave conductivity to study charge generation in a 1D model system of semiconducting single-walled carbon nanotubes (s-SWCNTs) in low-dielectric solvent. The observation of high conductivity, even for much less than one dopant per s-SWCNT on average, demonstrates that entropy plays a key role in facilitating charge carrier escape in 1D systems, despite prior suggestions to the contrary.

Free carrier generation in organic donor/acceptor heterojunctions and redox-doped organic semiconductors is poorly understood, since assumed tight electron–hole binding conflicts with observed high free carrier yields. Cornerstone analyses that have guided the field for over 15 years predict that entropy can stabilize free charges in 2D and 3D pi-conjugated semiconductors but not in 1D systems. Here, the impact of entropy on charge generation in 1D pi-conjugated semiconductors is revisited by exploiting a greatly simplified system where enthalpy considerations alone should not allow for free charge generation. Noncontact solution-phase microwave conductivity is used to investigate the carrier density-dependent conductivity and dielectric constant in isolated chemically doped semiconducting single-walled carbon nanotubes in a low-dielectric solvent. Dopant chemical structure dramatically influences the carrier density-dependent complex conductivity, with bulky dopants facilitating carrier escape even at carrier densities below one carrier per nanotube. Three distinct numerical calculations show that entropic stabilization dramatically lowers the Gibbs energy barrier for free charge generation, explaining the high yield of free carriers, even in 1D. This renewed understanding of entropy's role in carrier generation has important implications for designing organic electronic devices–such as solar cells and thermoelectric energy harvesters–for enhanced carrier yield, conductivity, and performance.

Variable-temperature small-angle X-ray scattering is used to investigate the solution aggregation behavior and processing resiliency of high-efficiency organic photovoltaics with an iodinated electron acceptor. The iodinated acceptor exhibits superior processing stability compared to its fluorinated counterpart. A direct link between the solution aggregation structure, active layer morphology, and photovoltaic performance is established, which can guide the optimization of device efficiency.

Polymer photovoltaics are promising for low-cost, flexible, and lightweight power supplies. Their performance is heavily influenced by the morphology of the polymer: acceptor blend, where the aggregation structures of both components play a crucial role in charge generation, transport, and overall device performance. This study probes and resolves the solution aggregation behavior and processing resilience of high-efficiency polymer photovoltaics incorporating an iodinated electron acceptor, BO-4I, using variable-temperature small-angle X-ray scattering and neutron scattering. By comparing BO-4I with its fluorinated counterpart, it is found that BO-4I exhibits excellent solution processing stability, whether in chlorobenzene or toluene. In addition, temperature-induced change in the donor:acceptor blend aggregation structure leads to significant alterations in film morphology, ultimately affecting device performance. Particularly, the stable solution aggregation structure of the BO-4I system confers processing resilience to device performance and achieves higher long-term device stability. Combining film structural analysis and device performance characterization, a structural inheritance is identified from solution to film, and determined that a organic photovoltaics polymer aggregate length of 27 ± 3 nm in solution is a key feature for achieving optimal efficiency in polymer photovoltaics. These findings provide valuable insights and guidance for designing future polymer photovoltaic systems.

2D crystalline Cu2Te nanosheets (c-Cu2Te NSs) are converted into oxygen-doped amorphous analogues (a-Cu2Te NSs) via controlled air calcination. This amorphization induces Cu 3d–O 2p orbital hybridization, enhancing electronic structure and active site density. The a-Cu2Te NSs deliver 91.7% ethylene Faradaic efficiency and 550 mA cm−2 partial current density with outstanding stability in electrocatalytic acetylene semi-hydrogenation.

Electrocatalytic acetylene semi-hydrogenation offers a sustainable and energy-efficient alternative to conventional thermocatalytic methods, yet remains challenged by competing side reactions, including hydrogen evolution, over-hydrogenation, and carbon-carbon coupling. Here, the transformation of 2D van der Waals crystalline Cu2Te nanosheets (c-Cu2Te NSs) into oxygen-doped amorphous analogues (a-Cu2Te NSs) via controlled air calcination is reported. The resulting a-Cu2Te NSs feature a disordered Cu coordination network and deliver an ethylene Faradaic efficiency of 91.7% at a high partial current density of 550 mA cm−2, along with excellent stability, outperforming both c-Cu2Te NSs and state-of-the-art catalysts. Mechanism investigations reveal that structural amorphization drives the redistribution of interlayer Cu atoms and alters key electronic properties, including the density of states and the Cu d-band center, through Cu 3d-O 2p orbital hybridization. These effects increase the density of accessible Cu active sites, optimize adsorption energetics, accelerate interfacial water dissociation, and promote hydrogen accumulation, thereby effectively suppressing undesirable side reactions. This work highlights amorphous engineering as a powerful strategy for designing high-performance electrocatalysts.

2D moiré superlattice composed of vertically stacked hexagonal boron nitride and graphene (hBN/Gr) demonstrates exceptional fracture toughness, primarily attributed to hBN's crack deflection and bifurcation mechanisms. Notably, this robust membrane withstands 200 extreme thermal shock cycles up to 1800 K at a heating rate of 10⁴ K s⁻¹. Such remarkable thermal stability facilitates the successful synthesis of high-entropy alloy nanoparticles.

Excellent mechanical strength and toughness are demanded for two-dimensional material (2DM) membranes in various applications to withstand extreme strain and temperature changes and resist crack propagation. However, the trade-off between strength and toughness poses significant challenges in meeting these requirements. This study presents a self-toughened 2D moiré superlattice membrane composed of vertically stacked hexagonal boron nitride and graphene (hBN/Gr) that exhibits high mechanical strength. The intrinsic toughness originates from the high energy release rate associated with the crack deflection and bifurcation in hBN. Remarkably, this robust membrane endures 200 cycles of thermal shock up to 1800 K with 104 K s−1 heating rate, during which high-entropy alloy nanoparticles (HEA-NPs) are successfully synthesized. The findings pave the way for the design and fabrication of robust 2D superlattices, facilitating future exploration under extreme conditions.

As a promising anode material for sodium-ion batteries, hard carbon stands out with its high Na storage capacity, structural stability, and safety. This review comprehensively summarizes and discusses its structural models, Na storage mechanisms, diverse modification strategies, and full-cell integration challenges, aiming to guide the development of high-performance, cost-effective sodium-ion batteries and inspire future research directions.

Sodium-ion batteries (SIBs) have emerged as a promising technology for large-scale energy storage due to their unique performance characteristics and raw material accessibility. Among various anode materials, hard carbon (HC) stands out due to its high Na storage capacity, structural stability, and intrinsic safety. However, the structural complexity and heterogeneity of HC present ongoing challenges in understanding its structural models and Na storage mechanisms, impeding the rational design and performance optimization of HC-based anodes. This review provides a systematic overview of recent advances in HC for SIBs, beginning with an in-depth examination of representative structural models and the underlying structure–property relationships. The review critically analyzes Na storage mechanisms and bridges these insights with a diverse array of modification strategies—including precursor design, structural tailoring, and surface/interface optimization. Special emphasis is placed on improving initial Coulombic efficiency, rate capability, and long-term cycling stability. Furthermore, practical challenges related to full-cell integration are discussed, such as pre-sodiation techniques and electrolyte/interface engineering to enhance the real-world applicability of HC. By integrating fundamental understanding with forward-looking design strategies, this review provides a valuable reference for the development of high-performance, cost-effective SIB systems, and to inspire future research directions in sodium-ion energy storage.

This study overcomes challenges in visualizing atomic-level defects in perovskite nanocrystals, promising to significantly improve the stability and performance of quantum dot-based light-emitting devices. Using double-Cs-corrected transmission electron microscopy, the study enables atomic-resolution imaging of elusive RuddlesdenPopper faults hidden within CsPbBr3-xIx nanocrystals. Lead, cesium, bromine, and iodine atoms are identified precisely, revealing their spatial arrangement within a single nanocrystal.

Atomic-resolution imaging of Ruddlesden–Popper (RP) interfaces is challenging due to their concealment within perovskite nanocrystals (NCs) and the inherent limitations of conventional characterization techniques. In this study, distinctly oriented RP faults have been detected using double-Cs-corrected high-angle annular dark-field scanning transmission electron microscopy (STEM). A simple yet reliable STEM approach to achieve atomically precise identification of Pb, Cs, Br, and I atoms and analyze their spatial atomic arrangements in a single NC is employed. In addition, dislocations caused by lattice mismatch at grain boundaries (GBs) are identified. Lattice strain in GBs and RPs is determined and quantified, revealing that neither of these planar defects introduces the deep trap levels. Therefore, in absence of Pb dangling bonds or Pb─Pb bonds in GBs and RPs plays a crucial role in stabilizing NCs and preventing ion migration. Incorporating n-octylammonium iodide in pristine CsPbBr3 quantum dots leads to the formation of CsPbBr3− x I x NCs, resulting in a significant redshift in electroluminescence (≈496–623 nm) with enhanced intensity (±79%), attributed to higher exciton lifetime, increased exciton binding energy, and improved carrier confinement in flexible light-emitting devices. Density functional theory calculations confirm that additional carriers localized at the interface enhance electron–hole recombination, ensuring stable charge transportation for lighting devices.