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NanoManufacturing

Michael De Volder, Engineering Department - IfM
 
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Table of Contents for Advanced Materials. List of articles from both the latest and EarlyView issues.
Updated: 2 days 5 hours ago

Solid Polymer Electrolyte with Dual Lewis‐Acid Filler for Ultra‐Stable Lithium Metal Batteries

Sat, 26/04/2025 - 07:05

The study reveals that Li+ transference number (t +), concentration (C 0), and diffusion coefficient (D) critically influence dendrite growth in SPEs. By developing dual-Lewis-acid fillers, these parameters are simultaneously enhanced, and constructed a stable inorganic SEI layer. The optimized electrolyte enables high-performance Li-metal batteries with NCM811/NCM622/LFP cathodes under demanding operating conditions.


Abstract

Solid polymer electrolytes (SPEs) are regarded as promising candidates that could address the safety concerns associated with liquid electrolytes. Nonetheless, SPEs are still confronting serious lithium dendrite issues, and there is a lack of systematic studies regarding the formation of lithium dendrites within SPEs. Herein, Sand equation is employed to elucidate the determinants of dendrite growth in SPEs, revealing that three factors including the Li+ transference number, Li+ diffusion coefficient, and Li+ concentration are positively correlated with Sand's time (τ) which determine the plating/striping behaviors of Li anode. More importantly, an effective and universal approach is proposed to construct dendrite-free polymer lithium metal batteries with dual-Lewis-acid materials such as Zinc Borate (ZB). Endowed with ZB materials, the PVDF-HFP based electrolyte possesses sufficient Li+ supply and swift transport channel and thus achieves an impressively high Li+ transference number of 0.9 and outstanding ionic conductivity at 30 °C (9.2 × 10−4 S cm−1), outperforming the polymer electrolytes with single Lewis-acid fillers. The electrolyte imparts the LFP//Li cell with exceptional capacity retention, showing almost no decay in discharge capacity even after 700, 500, and 300 cycles at 2 C, 3 C, and 5 C, respectively. Additionally, it capacitates the LiNi0.6Mn0.2Co0.2O2//Li cell to outperform by achieving over 1900 cycles at 1C and stably cycling under a cut-off voltage of 4.5V.

Mannosylated MOF Encapsulated in Lactobacillus Biofilm for Dual‐Targeting Intervention Against Mammalian Escherichia coli Infections

Fri, 25/04/2025 - 13:21

This study develops a dual-targeting nano-system (Zn-MOF@Man/LRB) against Escherichia coli infection. Mannosylated Zn-MOF aggregates bacteria via FimH recognition and disrupts biofilms, while Lactobacillus biofilm encapsulation enables gut-targeted immunomodulation and sustains nanomaterial release. The system restores microbiota equilibrium and promotes stem cell differentiation and barrier stability. This approach demonstrates cross-species anti-diarrheal efficacy, advancing safe and effective treatment that restores intestinal homeostasis for potential applications in both human medicine and animal husbandry.


Abstract

Pathogenic bacterial infections pose a major concern, especially concerning mammalian enteritis and diarrhea. Compared to conventional antibiotic intervention, metal–organic frameworks (MOFs) exhibit superior antibacterial properties and lower cytotoxicity, demonstrating great promise in the treatment of pathogen-induced diarrhea. However, the achievement of their precise targeted delivery is still a significant challenge. Herein, a novel precision nano-system with a dual-targeting approach for treating intestinal infections caused by Escherichia coli (E. coli) is designed. First, Zn-MOF was synthesized based on ZnO, which possessed enhanced elimination of planktonic bacteria and biofilms. Through mannosylation, Zn-MOF@Man specifically recognized the FimH pili of E. coli, leading to its aggregation and subsequent eradication. Second, guided by whole genome sequencing, the encapsulation of Lactobacillus biofilm exertd immunomodulatory function, overcomed challenges related to intestinal targeting, and facilitated sustained drug release. Furthermore, Zn-MOF@Man/LRB maintaind microbiota equilibrium and promoted stem cell differentiation and barrier stability, ensuring consistent anti-diarrheal and anti-inflammatory efficacy in mice, piglets, and humans. This approach represents a novel dual-targeting antimicrobial strategy, combining probiotic biofilms and E. coli-oriented delivery, advancing safe and effective treatment that restores intestinal homeostasis for potential applications in both human medicine and animal husbandry.

High‐Energy‐Density Aqueous Zinc‐Ion Batteries: Recent Progress, Design Strategies, Challenges, and Perspectives

Fri, 25/04/2025 - 13:15

Strategies achieving high-energy-density aqueous zinc-ion batteries are summarized and analyzed from both their separate advancements and the integrated effectiveness in this review. Then, perspectives are given for valuable guidance for further development of high-energy-density aqueous zinc-ion batteries.


Abstract

Aqueous zinc-ion batteries (AZIBs) are emerging as a promising energy storage technique supplementary to Li-ion batteries, attracting much research attention owing to their intrinsic safety, cost economy, and environmental friendliness. However, energy densities for AZIBs still do not fulfill practical requirements because of the low specific and areal capacity, limited working potential, and excessive negative-to-positive electrode capacity (N/P) ratio. In this review, a comprehensive overview of basic requirements and major challenges for achieving high-energy-density AZIBs is provided. Following that, recent progress in the optimization of each component and the overall configuration is summarized, and crucial design principles are discussed. Apart from conventional emphasis on each part, especially cathode materials, separately, the comprehensive discussion about the synergistic interactions among all components is conducted. Finally, the outlook and research direction are given to provide valuable guidance for the further holistic development of high-energy-density aqueous zinc-ion batteries.

Biophysical‐Inspired Interpenetrated Fibrillar and Reticular Collagen Scaffold with Vascular Endothelial Cell Membrane Incorporation for Guided In Situ Spleen Tissue Regeneration

Fri, 25/04/2025 - 13:11

The spleen's complex structure limits its regenerative capacity after injury, significantly impacting patient quality of life. This work develops an inducible scaffold mimicking spleen parenchyma, enhancing in situ regeneration. This scaffold reduces oxidative stress, recruits cells, and promotes tissue integration, while proteomics reveal activation of key metabolic pathways, enhancing splenic function and blood vessel regeneration.


Abstract

The spleen's complex structure and limited regenerative ability hinder its regrowth at the site of injure, affecting patient quality of life and risk severe complications. The spleen's stroma primarily consists of reticular and fibrillar collagen, supporting its microvascular network. Inspired by such biophysical environment, this work develops an inducible scaffold featuring an interpenetrating network structure of fibrous and reticular collagen, which is loaded with vascular endothelial cell membranes to facilitate in situ regeneration. The regenerated parenchyma includes red pulp, white pulp, and a vascular system. The scaffold effectively reduces oxidative stress at the injury site, recruits cells to degrade the scaffold, and promotes tissue integration, thereby accelerating spleen regeneration. Additionally, the regenerated tissue compensates for the spleen's functions, enhancing its ability to clear abnormal red blood cells and platelets. Proteomics and RNA sequencing analyses reveal that the scaffold induced the upregulation of key pathways, including the Wnt signalling pathway, Statin pathway, and amino acid metabolism pathway. This activation mobilizes splenic cells metabolism, enhances immune cell activity, and facilitates the remodeling of the extracellular matrix. Moreover, the incorporated cell membrane components promote splenic blood vessels regeneration by upregulating the neural crest cell differentiation pathway within the tissue.

Upcycling Spent Lithium‐Ion Batteries: Constructing Bifunctional Catalysts Featuring Long‐Range Order and Short‐Range Disorder for Lithium‐Oxygen Batteries

Fri, 25/04/2025 - 13:10

In this work, for the first time, an interesting strategy is proposed for upcycling Ni, Co, and Mn valuable metals from spent lithium-ion batteries into a bifunctional catalyst for lithium-oxygen batteries by a rapid Joule-heated thermal shock method. This is a well-defined catalyst combining both features of long-range order L12 face-centered cubic structure and short-range disorder in M sites. Benefiting from the unique atomic arrangement, the long-range order L12 structure significantly enhances the long-term stability of the catalyst, while the short-range disorder character of the M site triggers the cocktail effect and further activates the Pt catalytic kinetics. Experiments and theoretical results disclose that the local coordination environment and electronic distribution of Pt are both fundamentally modulated via surrounding disordered Ni, Co, and Mn atoms, which greatly optimize the affinity toward oxygen-containing intermediates and facilitate the deposition/decomposition kinetics of the thin-film Li2O2 discharge products. This distinctly lowers both the energy barriers of the oxygen reduction reaction and oxygen evolution reaction.


Abstract

Upcycling of high-value metals (M = Ni, Co, Mn) from spent ternary lithium-ion batteries to the field of lithium-oxygen batteries is highly appealing, yet remains a huge challenge. In particular, the alloying of the recovered M components with Pt and applied as cathode catalysts have not yet been reported. Herein, a fresh L12-type Pt3 M medium-entropy intermetallic nanoparticle is first proposed, confined on N-doped carbon matrix (L12-Pt3(Ni1/3Co1/3Mn1/3)@N-C) based on spent 111 typed LiNi1-x-yMnxCoyO2 cathode. This well-defined catalyst combines both features of long-range order L12 face-centered cubic structure and short-range disorder in M sites. The former contributes to enhancing the structural stability, and the latter further facilitates deeply activating the catalytic activity of Pt sites. Experiments and theoretical results demonstrate that the local coordination environment and electronic distribution of Pt are both fundamentally modulated via surrounding disordered Ni, Co, and Mn atoms, which greatly optimize the affinity toward oxygen-containing intermediates and facilitate the deposition/decomposition kinetics of the thin-film Li2O2 discharge products. Specifically, the L12-Pt3(Ni1/3Co1/3Mn1/3)@N-C catalyst exhibits an ultra-low overpotential of 0.48 V and achieves 220 cycles at 400 mA g−1 under 1000 mAh g−1. The work provides important insights for the recycling of spent lithium-ion batteries into advanced catalyst-related applications.

Shape Memory Networks With Tunable Self‐Stiffening Kinetics Enabled by Polymer Melting‐Recrystallization

Fri, 25/04/2025 - 13:04

Shape recovery of traditional shape memory polymers (SMPs) is often accompanied by a monotonic decrease in mechanical stiffness, thereby impacting their practical applications. Herein, a novel strategy is developed to construct the self-stiffening SMP triggered by single thermal stimulus by harnessing polymer melting-recrystallization. Conceptual application of self-stiffening SMP as a shape memory stent with self-enhancing supporting function is successfully demonstrated.


Abstract

Shape memory polymers (SMPs) are deformable materials capable of recovering from a programmed temporary shape to a permanent shape under specific stimuli. However, shape recovery of SMPs is often accompanied by the evolution of materials from a stiff to soft state, leading to a significant decrease in strength/modulus and thereby impacting their practical applications. Although some attempts are made to pursue the SMPs with self-stiffening capability after shape recovery, the modulus increase ratio is much limited. Inspired by the recrystallization process of CaCO3 during crab molting, a novel and universal strategy is developed to construct water-free self-stiffening SMPs by using a single thermal stimulus through harnessing the polymer melting-recrystallization. The shape recovery is achieved through the melting of polymer primary crystals, followed by the self-stiffening via polymer recrystallization at the same recovery temperature, in which the modulus increase rate and ratio can be programmed in a wide range. Additionally, conceptual applications of these self-stiffening SMPs as artificial stents with self-enhancing supporting function are successfully demonstrated. This work is believed to provide new insights for developing the advanced shape memory devices.

Protein‐Like Polymers Targeting Keap1/Nrf2 as Therapeutics for Myocardial Infarction

Fri, 25/04/2025 - 13:03

We describe a Keap1 targeting protein-like polymer (PLP) which activates Nrf2, an important cytoprotective transcription factor for relieving myocardial infarction-induced oxidative stress. This PLP increases cell survival in vitro in multiple relevant cardiac cell types and elicits pro-reparative responses, improving cardiac function in a preclinical model. Keap1 inhibiting PLPs show translational potential for ischemia reperfusion injury.


Abstract

Myocardial infarction (MI) results in oxidative stress to the myocardium and frequently leads to heart failure (HF). There is an unmet clinical need to develop therapeutics that address the inflammatory stress response and prevent negative left ventricular remodeling. Here, the Keap1/Nrf2 protein–protein interaction is specifically targeted, as Nrf2 activation is known to mitigate the inflammatory response following MI. This is achieved using a Nrf2-mimetic protein-like polymer (PLP) to inhibit the Keap1-Nrf2 interaction. The PLP platform technology provides stability in vivo, potent intracellular bioactivity, and multivalency leading to high avidity Keap1 binding. In vitro and in vivo assays to probe cellular activity and MI therapeutic utility are employed. These Keap1-inhibiting PLPs (Keap1i-PLPs) impart cytoprotection from oxidative stress via Nrf2 activation at sub-nanomolar concentrations in primary cardiomyocytes. Single-digit mg kg−1, single-dose, intravenous PLP administration significantly improves cardiac function in rats post-MI through immunomodulatory, anti-apoptotic, and angiogenic mechanisms. Thus Keap1i-PLPs disrupt key intracellular protein–protein interactions following intravenous, systemic administration in vivo. These results have broad implications not only for MI but also for other oxidative stress-driven diseases and conditions.

Ultrahigh Conductive MXene Films for Broadband Electromagnetic Interference Shielding

Fri, 25/04/2025 - 13:00

A new series of nitrogen-substituted MXene films, spanning the full composition range, achieves record-high conductivity (35 000 S cm⁻¹) and outstanding electromagnetic interference (EMI) shielding across X, Ka, and W bands, even in ultrathin layers. These solution-processable, lightweight films outperform metals and open new possibilities for high-frequency electronics and wireless communication systems of the future.


Abstract

Broadband and ultrathin electromagnetic interference (EMI)-shielding materials are crucial for efficient high-frequency data transmission in emerging technologies. MXenes are renowned for their outstanding electrical conductivity and EMI-shielding capability. While substituting nitrogen (N) for carbon (C) atoms in the conventional MXene structure is theoretically expected to enhance these properties, synthesis challenges have hindered progress. Here, it is demonstrated that Ti x C y N x - y -1T z MXene films with optimized N content achieve a record-high electrical conductivity of 35 000 S cm−1 and exceptional broadband EMI shielding across the X (8–12.4 GHz), Ka (26.5–40 GHz), and W (75–110 GHz) bands—outperforming all previously reported materials even at reduced thicknesses. By synthesizing a full series of high-stoichiometric Ti x AlC y N x - y -1 MAX phases without intermediate phases, the impact of N substitution on the physical and electrical properties of Ti x C y N x - y -1T z MXene flakes is systematically explored, achieving complete composition tunability in both dispersion and film forms. These findings position Ti x C y N x - y -1T z MXenes as promising candidates for applications spanning from conventional lower-frequency domains to next-generation sub-THz electronics.

Enhancing Room‐Temperature Spin Lifetimes in Molecular Semiconductors by Designing Intramolecular Dipole Orientations

Fri, 25/04/2025 - 12:58

A record spin lifetime of 106 µs at room temperature has been observed in reg-PAzE with a regular dipole orientation. Integrated theoretical and experimental results reveal that the extended spin lifetime arises from variations in the hyperfine interaction strength induced by intramolecular dipole orientations. The findings will provide valuable insights for designing molecular materials with long spin lifetimes.


Abstract

In spintronics, achieving long spin lifetimes, particularly at room temperature (RT), is a key objective for spin transport materials. Molecular semiconductors (MSCs), with their inherently weak spin relaxation mechanisms, have emerged as promising candidates for realizing long RT spin lifetimes. However, effective strategies to suppress spin relaxation through the design of molecular structures in MSCs are still not well understood, and as a result, spin lifetimes remain limited (≈ 10-µs level at RT). In this study, the impact of intramolecular dipole orientations on spin lifetimes in MSCs has been explored for the first time. Both theoretical and experimental results have demonstrated that dipole orientation influences the hyperfine interaction (HFI) effect (a main causation for spin relaxation), and thus, spin lifetime. By adjusting dipole arrangements through molecular design, it is demonstrated that the poly(2,6-azuleneethynylene) with a regular dipole orientation served to reduce the HFI strength and ultimately extended the spin lifetime to 106 µs in a spintronic device, much higher than that of the random arrangement, setting a new RT record. This work provides new insights into the spin relaxation mechanism and offers a valuable strategy for extending spin lifetimes in MSCs for future RT spintronic applications.

Super‐Wide Color Tunability from a Single Electrochromic Device through In Situ Reconstruction of Optical Cavity

Fri, 25/04/2025 - 12:54

A new strategy is proposed utilizing in situ, electrically driven reconstruction of optical cavities on an electrochromic electrode surface to fabricate electrochromic devices with super-wide color tunability. The device fabricated by this approach can create a wide variety of colors from yellow, orange, red, violet, blue, and cyan to green in a single electrochromic device that almost spans the entire visible region.


Abstract

Electrochromic (EC) displays, as non-emissive (passive) displays with low energy consumption, have garnered significant attention from both industry and academia in recent years. Nevertheless, traditional EC technology faces challenges in achieving full-color displays within a single device due to its limited color gamut, even though full-color capability is highly desirable for eliminating the need for complex RGB subpixel mosaics. Herein, a new strategy is proposed utilizing in situ, electrically driven reconstruction of optical cavities on an electrochromic electrode surface to fabricate EC devices with super-wide color tunability. The device fabricated by this approach can create a wide variety of colors from yellow, orange, red, violet, blue, and cyan to green in a single EC device that almost spans the entire visible region (Δhue approaches 360°). Apart from the super-wide color tunability, the devices also have small working voltage window (0.2-1.8 V), outstanding bistability (>8 h), extremely low power consumption (≈2.3 mW cm−2) and good cycling ability (≈4.3% decay rate after 1,000 cycles). Moreover, the super-wide color tunability of these EC devices has been demonstrated in diverse applications, including shifting rainbow flower images, color palettes, and information displays.

Synergistic Interface Engineering via o‐Difluorobenzene‐Mediated HPWO Crystallization and ITO Fluorination for 20.57% Efficiency Organic Solar Cells

Fri, 25/04/2025 - 12:49

A dual-action optimization strategy is developed combining the fluorination of ITO electrodes with precisely controlled crystallization of phosphotungstic acid, which establishes favorable energy level alignment and reduces interface trap density to obtain 20.57% efficiency of organic solar cells.


Abstract

Interfacial energy loss is a critical challenge in achieving high-efficiency organic solar cells (OSCs), primarily due to mismatched energy levels and inefficient charge collection. Herein, a bifunctional interface engineering strategy is proposed, employing an ethanol/o-difluorobenzene (EtOH/o-DFB) dual-solvent system for phosphotungstic acid (HPWO) processing. During film formation, o-DFB regulates HPWO crystallization by suppressing excessive aggregation, while enabling in situ ITO fluorination through the adsorbed o-DFB. This synergistic approach simultaneously mitigates the trap-assisted nonradiative recombination at the hole transport layer while enhancing the electrode work function, resulting in better ohmic contact, minimized trap-state densities, and improved energy level alignment at the electrode/active layer interface. The effectiveness of this strategy is demonstrated across multiple active layer systems. Remarkable power conversion efficiencies of 19.55%, 20.07%, and 20.57% are achieved for PM6/L8-BO, D18/L8-BO, and D18/BTP-eC9-based OSCs, respectively. Notably, the 20.57% PCE represents one of the highest efficiencies reported to date for OSCs, highlighting the potential of this bifunctional interface engineering strategy in advancing high-performance organic photovoltaics.

Advancements in Carbon‐Based Piezoelectric Materials: Mechanism, Classification, and Applications in Energy Science

Fri, 25/04/2025 - 12:48

Carbon-based piezoelectric materials are systematically categorized based on their structural and functional properties. The mechanisms of stress-induced charge transfer are elucidated, and their applications are explored across three key domains: piezoelectric catalysis for energy conversion and environmental remediation, piezoelectric biomedical treatments for tissue regeneration and antitumor therapies, and piezoelectric generators and sensors for energy harvesting and advanced sensing technologies.


Abstract

The piezoelectric phenomenon has garnered considerable interest due to its distinctive physical properties associated with the materials involved. Piezoelectric materials, which are inherently non-centrosymmetric, can generate an internal electric field under mechanical stress, enhancing carrier separation and transfer due to electric dipole moments. While inorganic piezoelectric materials are often investigated for their high piezoelectric coefficients, they come with potential drawbacks such as toxicity and high production cost, which hinder their practical applications. Consequently, carbon-based piezoelectric materials have emerged as an alternative to inorganic materials, boasting advantages such as a large specific surface area, high conductivity, flexibility, and eco-friendliness. Research into the applications of carbon-based piezoelectric materials spans environmental remediation, energy conversion, and biomedical treatments, indicating a promising future. This review marks the first comprehensive attempt to discuss and summarize the various types of carbon-based piezoelectric materials. It delves into the underlying mechanisms by which piezoelectricity influences catalysis, biomedical applications, nanogenerators, and sensors. Additionally, various potential techniques are presented to enhance the piezoelectric performance. The design principles of representative fabrication strategies for carbon-based piezoelectric materials are analyzed, emphasizing their current limitations and potential improvements for future development. It is believed that recent advances in carbon-based piezoelectric materials will make a significant impact.

Weak Dipole Effect Customized Zinc Ion‐Rich Protective Layer for Lean‐Electrolyte Zinc Metal Batteries

Fri, 25/04/2025 - 12:46

A zwitterionic protective layer is engineered on Zn surface by weak dipole effect of TMAO. The weak dipole effect realizes Zn ion-rich environment to alleviate the concentration polarization on electrolyte/Zn interface and exhibits short range interaction with free water to inhibit side reactions, thereby achieving enhanced performance for both symmetrical and full batteries with lean-electrolyte.


Abstract

The industrial development of Zn-ion batteries requires high performance even with lean-electrolyte. Nevertheless, lean-electrolyte can exacerbate concentration polarization at the interface of electrode/electrolyte, leading to significant Zn corrosion and battery failure. Here, a stable Zn ion-rich protective layer (TMAO-Zn) is constructed by a unique zwitterion structure of trimethylamine N-oxide (TMAO). The TMAO is characterized by the direct connection between positive and negative charges (N+-O−) with minimal dipole moment, which renders weak dipole interactions to form the TMAO-Zn layer with Zn2+, thereby reducing concentration polarization and promoting the rapid and uniform deposition of Zn2+. Furthermore, the O of TMAO-Zn exhibits the higher electrophilic index, indicating a stronger propensity for stable hydrogen bond interactions with active free water in the inner Helmholtz layer (IHL), thereby mitigating corrosion under extreme conditions of low electrolyte-to-capacity ratio (E/C ratio). Consequently, the symmetrical Zn battery with TMAO-Zn enables stable cycling for over 250 h with lean-electrolyte of 15 µL mA h−1. Additionally, Zn/I₂ pouch battery with a low E/C ratio of 21.2 µL mA h−1 provides ultra-high stable specific capacity of 96 mA h for over 250 cycles (capacity retention rate of 98.3%). This study offers a new concept to propel the practical application of Zn batteries with lean-electrolyte.

A High‐Throughput Approach to Identifying Environment‐Friendly Artificial Antisolvents for Efficient Perovskite Solar Cells

Fri, 25/04/2025 - 12:41

A high-throughput approach is used to screen 40 perovskite antisolvents and pinpoint specific regions favorable for the formation of high-quality perovskite films based on Hansen solubility parameters (HSPs). The low-toxicity candidates are obtained by adjusting the HSPs and validated for different perovskite compositions.


Abstract

Rapid crystallization facilitated by antisolvents is widely employed for producing high-quality perovskite films, but constrained by the limited variety and high toxicity of conventional solvents, underscoring the need for sustainable and low-toxicity solvent systems for large-scale production. In this study, a systematic screening of over 40 antisolvents is conducted using a high-throughput platform, uncovering a significant correlation between the antisolvent properties within Hansen solubility space and the structural and optoelectronic characteristics of the resultant perovskite films. A Hansen solubility sphere is subsequently constructed, pinpointing a specific region within this space that is most conducive to the formation of high-quality perovskite films. The underlying mechanism is further elucidated: antisolvents situated outside this optimal region either induce a rapid extraction of N,N-dimethylformamide (DMF), thereby limiting grain growth due to insufficient crystallization time or fail to adequately extract DMF. Since no ideal low-toxicity single antisolvent is found, a general concept based on solvent combinations with ultra-low-toxicity is introduced to solve the issues. The design rule for environment-friendly “artificial” solvents, which is validated for different perovskite compositions, paves the way for sustainable development and production of perovskite-based optoelectronic technologies.

Tunable Bipolar Photothermoelectric Response from Mott Activation for In‐Sensor Image Preprocessing

Fri, 25/04/2025 - 12:41

This study introduces a gate-tunable bipolar photothermoelectric detector using a vanadium dioxide film transistor. The device offers broadband photoresponse, linear light-intensity dependence, adjustable responsivities, low energy use (8 pJ per spike), and high stability (over 5000 cycles). An integrated convolutional network excels in broadband image classification, medical image denoising, and retinal vessel segmentation, highlighting its potential for future smart edge sensors.


Abstract

In-sensor image preprocessing, a subset of edge computing, offers a solution to mitigate frequent analog-digital conversions and the von Neumann bottleneck in conventional digital hardware. However, an efficient in-sensor device array with large-scale integration capability for high-density and low-power sensory processing is still lacking and highly desirable. This work introduces an adjustable broadband photothermoelectric detector based on a phase-change vanadium dioxide thin-film transistor. This transistor employs a vanadium dioxide/gallium nitride three-terminal structure with a gate-tunable phase transition at the gate-source junctions. This design allows for modulable photothermoelectric responsivities and alteration of the short-circuit photocurrent's polarities. The devices exhibit linear gate dependence for the broadband photoresponse and linear light-intensity dependence for both positive and negative photoresponsivities. The device's energy consumption is as low as 8 pJ per spike, which is one order of magnitude lower than that of previous Mott materials-based in-sensor preprocessing devices. A wafer-scale bipolar phototransistor array has also been fabricated by standard micro-/nano-fabrication techniques, exhibiting excellent stability and endurance (over 5000 cycles). More importantly, an integrated in-sensor convolutional network is successfully designed for simultaneous broadband image classification, medical image denoising, and retinal vessel segmentation, delivering exceptional performance and paving the way for future smart edge sensors.

Processable and Recyclable Covalent Organic Framework Gel Electrolytes

Fri, 25/04/2025 - 12:40

The preparation of COF gels is demonstrated and presents a method for solution-based reconstruction of COF gel electrolytes, inspired by the operational principle of wedges. By introducing oxygen atoms into the framework, the interaction forces are modulated between the framework layers and introduce active sites for trifluoroacetic acid (TFA). This approach enables the exfoliation of COF layers, allowing them to be effectively dispersed as a nanosheet in an aqueous-TFA solution. Furthermore, by taking advantage of the dynamic nature of imine bond and controlling the ratio of TFA to water, this manages the competitive interactions between TFA, COF, and water molecules, enabling the reconfiguration of COF materials from nanosheet dispersions back to gels. The obtained gel material demonstrated exceptional cycling stability, and sustaining performance.


Abstract

Covalent organic framework (COF)-based electrolytes with abundant ordered channels and accessible interaction sites have shown great potential in energy storage and transformation, although their practical applications are strongly impeded by their inherent insolubility and non-melt processability. Developing processable COF gel electrolytes and recycling them remains a formidable challenge. In this study, the processing of COF to gels demonstrated through interlayer interaction manipulation and enable solution-reconstruction of COF gel electrolytes for the first time, inspired by the working principle of wedges. Good solution-processability of the COF powders in strong acid mediums is achieved by inserting oxygen atoms into its framework to promote the interlayer charge repulsion. This modification enabled the COF readily dispersable as colloidal nanosheets in an aqueous solution of trifluoroacetic acid (TFA). Starting from here, this is modulated competitive interactions among TFA, COF, and water molecules, to reconfigure COF materials between their gelified and colloidally dispersed states. The reconfigured COF gel maintains their mechanical properties and long cycle life as an electrolyte in the battery (>800 h). This approach realizes solution processing of COF powders and can recycle COF out of gels for repeated use, offering new insights and strategies for their preparation and sustainable recycling.

Substitution Index‐Prediction Rules for Low‐Potential Plateau of Hard Carbon Anodes in Sodium‐Ion Batteries

Fri, 25/04/2025 - 09:00

The substitution index of precursor (Δ) is established as an effective predictor for the low-potential plateau performance of hard carbon (HC) anodes in sodium-ion batteries. Three carbon models—disordered carbon, closed-pore-dominated carbon, and turbostratic carbon—are constructed to validate the accuracy of Δ and investigate the mechanisms of closed pore formation and sodium storage.


Abstract

Establishing prediction rules for the low-potential plateau (LPP) of hard carbon (HC) anodes is crucial for constructing high-energy-density sodium-ion batteries (SIBs). While current studies suggest that the closed pores of HC can enhance the LPP performance, the rules for directly predicting the LPP from precursors have yet to be established. Here, prediction rules for the LPP of HC anodes in SIBs—the substitution index (Δ) of precursor are introduced. Three carbon models (disordered carbon, closed-pore-dominated carbon, and turbostratic carbon) are constructed to verify the accuracy of Δ and to explore the closed-pore formation and LPP mechanism. In detail, as the Δ increases from 0.06 to 0.22, the LPP capacity rises from 25 to 278 mAh g⁻¹, revealing a strong linear correlation between Δ of precursor and LPP capacity. In situ XRD, Raman, and ex situ SAXS, EPR further confirm that sodium storage in HC can be categorized into adsorption (>0.4 V), interlayer storage (0.4 to 0.15 V), and pore-filling (below 0.15 V). This work not only elucidates the sodium storage mechanisms, but also provides one efficient design guideline for advanced carbon anodes in SIBs.

Modulating Coupled Polyhedral Distortion in Li‐Rich Cathodes for Synergistically Inhibiting Capacity and Voltage Decay

Fri, 25/04/2025 - 08:59

Based on density functional theory calculations, machine learning, and experimental validation, a general design approach is provided to suppress performance degradation by modulating coupled polyhedral distortion in layered cathode materials. The developed Li-rich cathode exhibits remarkable long-term capacity and voltage stability, with 95.8% capacity retention after 300 cycles and 0.02% voltage decay per cycle.


Abstract

Achieving significant enhancements in both capacity and voltage stability remains a formidable challenge for Li-rich layered cathodes. The severe performance degradation is attributed to large lattice strain, irreversible oxygen release and transition metal migration, but the most critical factor responsible for structural destabilization is still elusive. Here, based on density functional theory calculations, machine learning and experimental validation, a multi-hierarchy screening of complex multi-element doping systems is developed from electrochemical activity, lattice strain, oxygen stability and transition metal migration barrier. It is further identified that the coupled polyhedral distortion parameter D+σ2 of the substitution element is the most significant feature that affects the structural stability during cycling. The Li-rich layered cathode developed based on the predicted results exhibits remarkable long-term capacity stability (95.8% capacity retention over 300 cycles) and negligible voltage loss (0.02% voltage decay per cycle). This study provides a general approach by modulating coupled polyhedral distortion for the rational design of cathode materials and can be expanded to the discovery of other advanced electrodes.

Developing Quasi‐Solid‐State Ether‐Based Electrolytes with Trifluorotoluylation Ionic Liquids for High Voltage Lithium Metal Batteries

Fri, 25/04/2025 - 08:33

This study proposes molecular design strategies to develop trifluorotoluylation ILs that enable quasi-solid-state ether-based electrolytes for high-voltage LMBs. The designed ILs greatly enhance the oxidative stability of the electrolyte and effectively suppress the dissolution of transition metal ions, facilitating the formation of a LiF-rich interfacial layer on the lithium anode, promoting uniform distribution of Li+ and regular deposition of lithium.


Abstract

The practical application of quasi-solid-state ether-based electrolytes is hindered by lithium dendrite formation and poor oxidation stability, which reduce the cycle life and energy density of the battery. Here, taking advantage of the ionic liquids’ high ionic interactions and structural flexibility in forming an optimized electrode/electrolyte interface, a pyrrolidinium-based ionic liquids with trifluorotoluylation cationic segment is designed and developed. The oxidation of anions in the electrolytes is induced to form a robust inorganic LiF-rich interphase at the cathode, thereby effectively achieving high oxidation stability and suppressing the dissolution of transition metal ions. In addition, the LiF interphases derived from the trifluorotoluylation cations increase the modulus of the anode interface and suppress the growth of lithium dendrites. Therefore, the Li-LiFePO4, Li-LiCoO2, and Li-LiNi0.8Co0.1Mn0.1O2 full cells with the optimized electrolytes demonstrate remarkable performance improvements at high current density (10 C), a wide voltage range of 4.5 V, a high mass loading of 11.1 mg cm−2, and a wide temperature range of −20–80 °C. Furthermore, a 2.66 Ah-level pouch cell with a high-energy-density of exceeding 356 Wh kg‒1 and excellent cyclic stability demonstrates the potential of the strategy in providing a path for the practical application of quasi-solid-state ether-based electrolytes in high-energy-density batteries.

From Metals to Polymers: Material Evolution and Functional Advancements in Current Collectors

Fri, 25/04/2025 - 08:29

The advantages, applications, challenges, and prospects of current collectors have been comprehensively reviewed, covering various types of metal current collectors, carbonaceous current collectors, conductive polymer current collectors, and organic–inorganic hybrid current collectors. The high-performance, multi-structured, and functionalized novel current collectors play a crucial role in advancing batteries with high performance, safety, and intelligence for next-generation energy storage devices.


Abstract

The rapid advancement of rechargeable batteries is hindered by insufficient energy density, limited design flexibility, and safety concerns, which pose significant challenges to their practical application. This review summarizes the crucial yet often overlooked role of current collectors in addressing these challenges. Recent progress across four types of current collectors, deriving from metal foils, carbonaceous substrates, conductive polymers, and organic–inorganic hybrids is systematically analyzed. Metal foils, as the most widely used current collectors, now face challenges including corrosion susceptibility and high volumetric density. Carbonaceous and polymer-based alternatives offer lightweight design and structural flexibility, but face limitations in conductivity and scalable production. Notably, organic–inorganic hybrid current collectors, leveraging material engineering and hierarchical design, offer a promising avenue to enhance battery safety and intelligence. Further, potential directions for current collector development, emphasizing 1) enhanced battery performance, 2) multiscale structural adaptability, and 3) integrated multifunctional design, providing prospective insights for next-generation energy storage devices are outlined.

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