Ultrahigh Efficiency Research Articles

Interfacial Domino Effect Triggered by β‐Alanine Cations Realized Highly Reversible Zinc‐Metal Anodes

AbstractRealizing durative dense, dendrite‐free, and no by‐product deposition configuration on Zn anodes is crucial to solving the short circuit and premature failure of batteries, which is simultaneously determined by the Zn interface chemistry, electro‐reduction kinetics, mass transfer process, and their interaction. Herein, this work unmasks a domino effect of the β‐alanine cations (Ala+) within the hydrogel matrix, which effectively triggers the subsequent electrostatic shielding and beneficial knock‐on effects via the specifical adsorption earliest event on the Zn anode surface. The electrostatic shielding effect regulates the crystallographic energetic preference of Zn deposits and retards fast electro‐reduction kinetics, thereby steering stacked stockier block morphology and realizing crystallographic optimization. Meanwhile, the mass transfer rate of Zn2+ ions was accelerated via the SO42− anion immobilized caused by Ala+ in bulk electrolyte, finally bringing the balance between electroreduction kinetics and mass transfer process, which enables dendrite‐free Zn deposition behavior. Concomitantly, the interfacial adsorbed Ala+ cations facilitate the electrochemical reduction of interfacial SO42− anions to form the inorganic‐organic hybrid solid electrolyte interphase layer. The above domino effects immensely improve the utilization efficiency of Zn anodes and long‐term stability, as demonstrated by the 12 times longer life of Zn||Zn cells (3650 h) and ultrahigh Coulombic efficiency (99.4 %).

Biodegradable Poly (L-Lactic acid) Fibrous Membrane with Ribbon-Structured Fibers and Ultrafine Nanofibers Enhances Air Filtration Performance.

Here, the poly (l-lactic acid) (PLLA) membrane with multi-structured networks (MSN) is successfully prepared by electrospinning technology for the first time. It is composed of micron-sized ribbon-structured fibers and ultrafine nanofibers with a diameter of tens of nanometers, and they are connected to form the new network structure. Thanks to the special fiber morphology and structure, the interception and electrostatic adsorption ability for against atmospheric particulate matter (PM) are significantly enhanced, and the resistance to airflow is reduced due to the "slip effect" caused by ultrafine nanofibers. The PLLA MSN membrane shows excellent filtration performance with ultra-high filtration efficiency (>99.9% for PM2.5 and >99.5% for PM0.3) and ultra-low pressure drop (≈20Pa). It has demonstrated filtration performance that even exceeds current non-biodegradable polymer materials, laying the foundation for future applications of biodegradable PLLA in the field of air filtration. In addition, this new structure also provides a new idea for optimizing the performance of other polymer materials.

Tailored multilayered films of the PVDF/Ba0.8Sr0.2TiO3 nanocomposites with surface-modified nanoparticles for superior dielectric and energy storage performance

The multilayer thick film (∼40 μm) of polyvinylidene fluoride-Ba0.8Sr0.2TiO3 (PVDF-BST) have been synthesized by a tape-casting technique. The incorporated BST nanoparticles in the PVDF matrix are functionalized by −PO4−3and −OH−group, which are abbreviated as PBST-P and PBST-H multilayer films. The nature of the functional group attached with the BST nanoparticles is found to strongly influence the dielectric properties, breakdown strength and energy storage behavior of the multilayer films. The dielectric constant (at 1 kHz) of PBST-P multilayer film shows a significant increase (∼30) as compared to PBST-H film (∼22), whereas the tangent loss remains the same. The breakdown strength of PBST-P multilayer film is also high (∼381 MV/m) as compared to the PBST-H film (∼318 MV/m). PBST-P film also possesses high discharge energy density (∼7.97 J/cc at 1800 kV) and ultrahigh energy efficiency (∼98 %). Enhanced dielectric and energy storage properties of PBST-P film is attributed to the strong bridging interaction between the PVDF matrix and BST-P nanofiller, which creates additional dipoles and a strong local electric field at the interfaces. The study may lead towards the novel ways of developing polymer-ceramic nanocomposites for high-energy density capacitors, where the incorporation of functionalized nanoparticles in the polymer matrix is accompanied by the architectured structure.

Bubble-induced self-assembly synthesis of defective hierarchical boehmite with ultra-high removal efficiency towards Congo red: Preparation and adsorption mechanism

To cope with the increasingly urgent environmental issue and provide promising alternative adsorbents, the synergistic preparation route of dissolution and bubble-induced self-assembly was firstly exploited to guide the reconstruction process of a defective hierarchical porous boehmite-microspheres (BMS) adsorbent in a favorable direction to improve the CR adsorption capacity using aluminium hydroxide industrial waste as raw materials. Multiple non-in-situ physicochemical characterization instruments demonstrate that BMS-4 adsorbent possesses abundant coordinatively unsaturated Al–species, large specific surface area, high porosity, oxygen vacancies and oxygen-containing groups, which promote the maximum adsorption capacities for CR up to 6805.08 ± 5.4 mg g−1. Moreover, the Pseudo-second order model and the Langmuir model are more suitable for describing the behavior of CR adsorption, which proves it is more inclined to be monolayer adsorption and there is no chemical reaction between CR and adsorbent. More importantly, it can be practiced in eight cycles of adsorption tests, achieving ultra-high stability for over 94.46 % of the original adsorption capacity. Combined with density-functional theory (DFT) calculations and experimental results, it is illustrated that the amino protonation is responsible for the additional enhancement of CR adsorption, in addition, oxygen vacancy capture and BMS-4/CR–SO3+–NH3 mechanism for enhanced adsorption of dyes is proposed, both of which show that bubble-induced self-assembly provides a promising route for the preparation of high-performance adsorbents.

Achieving ultra-high efficiency in directed energy deposition of pure copper on Inconel 718 substrate with a 3500 W blue laser

High efficiency deposition of highly reflective copper on a nickel-based superalloy substrate presents a significant challenge. This study first used a 3500 W high-power and 7.5 mm2 large-spot blue laser in Directed Energy Deposition, and successfully deposited copper on an Inconel 718 substrate. The process exhibited stability, with no significant cracks or pores observed. To the best of our knowledge, we have achieved the highest cladding efficiency of 62.84 mm2/s in the current cladding of copper. The interface between copper and Inconel 718 displayed a smooth composition transition at 3500 W, and the width reached 418 μm. The cladding layer displayed a columnar dendritic morphology at the bottom, gradually transitioning to equiaxed dendrites at the top. Dendrites enriched in elements found in Inconel 718 solidified, while Cu from the powder mainly solidified in the interdendritic region. The utilization of a high-power, large-spot blue laser offers a promising process for the efficient fabrication of large Cu/Ni dissimilar structural components.

Ultrahigh Dielectric Energy Density and Efficiency in PEI‐Based Gradient Layered Polymer Nanocomposite

AbstractDielectrics with high‐energy‐storage performance are highly desired for increasing compact‐size energy storage, and integration of modern power electronics. However, an ever‐existing challenge is to achieve both high efficiency (η) and high energy density (Ue). Here, a gradient‐layered (five‐layer) polyetherimide (PEI)‐based nanocomposite is presented. Different from traditional layered structures (modulation of filler volume fraction), multistage gradient interfaces are constructed by modulating the particle sizes of barium titanate nanoparticles (BaTiO3 NPs) to decrease sequentially from top to bottom. In this structure, three BaTiO3 NPs/PEI layers are clamped by two boron nitride nanosheets (BNNSs)/PEI layers. It is demonstrated that the gradient structure can suppress breakdown and confer high interfacial polarization, simultaneously. Consequently, the nanocomposite possesses an enhanced Ue of 16.38 J cm−3, and an ultrahigh η of 97.79%, far exceeding previously reported polymer nanocomposites. Furthermore, this nanocomposite also demonstrates satisfactory high‐temperature energy storage performances, achieving a Ue of 7.36 J cm−3 and an η of 83.12% at 150 °C. This gradient layered structure design opens a new way to explore high‐performance dielectric polymer nanocomposite with both ultrahigh Ue and η.

Feasibility Analysis of Power Generation from Internal Combustion Engine (ICE) Using EDAS Method

The popularity and development of electric motorcycles are exploding. This is merely the beginning of what many predict will be the motorbike industry's fastest-growing sector. Research significance: The next development in motorcycle technology is the electric motorcycle. High-point electric bikes that are lighter, economical, and enjoyable to ride may be easily offered to clients and partners globally by combining the superlative capabilities of a traditional motorbike with the most cutting-edge technologies now accessible. A future era of electric engines and regulators with "ultra-high efficiency, high power-to-weight, and lightweight" has been specifically created to advance a wide range of models. Methodology: Due to the abundance of possibilities offered on the global market, conflicting situations can develop while choosing a certain motorcycle. There may not necessarily be a certain number of options available or there may be multiple alternatives to the original pick. The possibility of not having an acceptable option for the criterion exists as well. “Multiple Criteria Decision Making” is a technique designed for the optimization of problems with an “infinite or finite number of choices” and the MCDM technique “EDAS method” is used to optimize the process in this paper. The rank of “Revolt RV400 is fifth, Joy e-Bike Monster is ninth, Tork Kratos R is fourth, Komaki Ranger is third, Cyborg Bob is sixth, Odysse Evoqis is seventh, Oben Rorr is first, PURE EV eTryst 350 is eight, Pure ecoDryft is second”. The ranking order is “Oben Rorr> Pure ecoDryft> Komaki Ranger> Tork Kratos R> Revolt RV400> Cyborg Bob> Odysse Evoqis> PURE EV eTryst 350”. Depending on EDAS research in this paper, it was discovered that among all sample electric motor vehicles, “Oben Rorr had the best overall performance while PURE EV eTryst 350 had the poorest”.

All-optical modulator with photonic topological insulator made of metallic quantum wells

Abstract All-optical modulators hold significant prospects for future information processing technologies for they are able to process optical signals without the electro-optical convertor which limits the achievable modulation bandwidth. However, owing to the hardly-controlled optical backscattering in the commonly-used device geometries and the weak optical nonlinearities of the conventional material systems, constructing an all-optical modulator with a large bandwidth and a deep modulation depth in an integration manner is still challenging. Here, we propose an approach to achieving an on-chip ultrafast all-optical modulator with ultra-high modulation efficiency and a small footprint by using photonic topological insulators (PTIs) made of metallic quantum wells (MQWs). Since PTIs have attracted significant attention because of their unidirectional propagating edge states, which mitigate optical backscattering caused by structural imperfections or defects. Meanwhile, MQWs have shown a large Kerr nonlinearity, facilitating the development of minimally sized nonlinear optical devices including all-optical modulators. The proposed photonic topological modulator shows a remarkable modulation depth of 15 dB with a substantial modulation bandwidth above THz in a tiny footprint of only 4 × 10 µm2, which manifests itself as one of the most compact optical modulators compared with the reported ones possessing a bandwidth above 100 GHz. Such a high-performance optical modulator could enable new functionalities in future optical communication and information processing systems.

Multifunctional electrolyte additive of a natural sweetener for promoting uniform Zn plating in a high-performance aqueous Zn ion batteries

Xylitol as a natural sweetener is introduced as an additive to the ZnSO4 electrolyte. The xylitol with massive hydroxyl groups can bind Zn ions and achieve preferential adsorption on Zn surface, effectively avoiding the Zn accumulation, relieving free water attack and inducing uniform Zn deposition, so as to inhibit the dendrite formation and interface corrosion. Batteries using the electrolyte with xylitol can deliver an ultra-long stable lifespan over 800 h at 10 mA cm−2 and achieve an ultra-high average Coulombic efficiency of 99.77 % for 800 cycles at 5 mA cm−2.

Application of the EDAS Technique for Selecting the Electric Motor Vehicles

The popularity and development of electric motorcycles are exploding. This is merely the beginning of what many predict will be the motorbike industry's fastest-growing sector.The next development in motorcycle technology is the electric motorcycle. High-point electric bikes that are lighter, economical, and enjoyable to ride may be easily offered to clients and partners globally by combining the superlative capabilities of a traditional motorbike with the most cutting-edge technologies now accessible. A future era of electric engines and regulators with "ultra-high efficiency, high power-to-weight, and lightweight" has been specifically created to advance a wide range of models. Due to the abundance of possibilities offered on the global market, conflicting situations can develop while choosing a certain motorcycle. There may not necessarily be a certain number of options available or there may be multiple alternatives to the original pick. The possibility of not having an acceptable option for the criterion exists as well. “Multiple Criteria Decision Making” is a technique designed for the optimization of problems with an “infinite or finite number of choices” and the MCDM technique “EDAS method” is used to optimize the process in this paper. The rank of “Revolt RV400 is fifth, Joy e-Bike Monster is ninth, Tork Kratos R is fourth, Komaki Ranger is third, Cyborg Bob is sixth, Odysse Evoqis is seventh, Oben Rorr is first, PURE EV eTryst 350 is eight, Pure ecoDryft is second”. The ranking order is “Oben Rorr> Pure ecoDryft> Komaki Ranger> Tork Kratos R> Revolt RV400> Cyborg Bob> Odysse Evoqis> PURE EV eTryst 350”. Depending on EDAS research in this paper, it was discovered that among all sample electric motor vehicles, “Oben Rorr had the best overall performance while PURE EV eTryst 350 had the poorest”.

DFT-assisted design of curcumin-based donor-π-bridge-acceptor molecular structures: Advancing nonlinear optical materials and sustainable organic solar cells

This study explores the theoretical design of novel curcumin-based structures with enhanced nonlinear optical (NLO) characteristics. By systematically substituting hydroxyl (OH) functionalities in bisdemethoxycurcumin (BdMC) with various donor and acceptor functionalities at the edges of the π-bridge backbone, we constructed 12 different derivatives. Density-functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were performed at the B3LYP/6-311++G(d,p) and CAM-B3LYP/6-311++G(d,p) levels to analyze the optoelectronic properties. The introduction of donors and acceptors significantly improved NLO characteristics. Notably, BdMC-1 (N(C2H5)2-π-bridge-NO2) exhibited a remarkable enhancement in NLO responses, with the average polarizability (<α>) and the first hyperpolarizability (βtot) increasing from 465.3 to 660.9 (a.u.) and 14254.4 to 143487.6 (a.u.), respectively. UV–Vis spectroscopy showed BdMC-1 as the most red-shifted compound, with a maximum wavelength (λmax) of 431.1 nm, the lowest optical bandgap of 2.88 eV, and an ultrahigh light harvesting efficiency (LHE) of 97.4%. The designed compounds exhibited narrower HOMO-LUMO electronic bandgaps (as low as 2.08 eV) compared to BdMC (3.32 eV), contributing to the improved NLO responses. Natural bond orbital (NBO) analysis confirmed the formation of a charge separation state, facilitating effective electron migration from donors to acceptors through the π-bridge. Additionally, using BdMC-based materials as acceptors in organic solar cells (OSCs) yielded open-circuit voltages (Voc) from 1.62 to 2.23 V, fill factors (FF) above 90%, and low exciton binding energies (Ee−b) in the range of 0.08 to 0.80 eV.

Non-sacrificial additive regulated electrode–electrolyte interface enables long-life, deeply rechargeable aqueous Zn anodes

Rechargeable aqueous Zn batteries (RAZBs) offer a promising solution for safe and cost-effective energy storage. However, practical applications of this type of battery are hindered by dendrite formation and side reactions, which primarily stem from the unstable Zn electrode–electrolyte interface (EEI). Here, we report 3-(1-pyridinio)-1-propanesulfonate (PPS) as a novel EEI regulator to tackle these critical issues. Theoretical calculations and experimental results reveal that PPS molecules can be preferentially adsorbed on the Zn anode surface and construct a lean-water EEI, which regulates uniform Zn plating/stripping and minimizes interfacial side reactions. As a result, the addition of PPS enables a Zn//Cu asymmetric cell to achieve an ultra-high Coulombic efficiency of 99.88 % and a lifespan of over 4,000 cycles (around half a year), far exceeding that with a conventional electrolyte (99.65 % and 210 cycles). Remarkably, even at 20 mA cm−2 and a high depth of discharge of 70 %, the Zn//Zn battery using the new electrolyte can still maintain an impressive cycling life of over 250 h. More importantly, the implementation of the designed electrolyte in various Zn-based full cells yields exceptional capacity retention and lifespan. This work underscores the importance of EEI regulation in advancing RAZB technology and offers a simple yet effective strategy for enhancing the stability and reversibility of Zn anodes, which represents a key step toward realizing the full potential of RAZBs for next-generation energy storage.

Advanced energy storage properties and multi-scale regulation mechanism in (1-x)(Bi0.5Na0.5)0.7Sr0.3TiO3-xCa(Nb0.5Al0.5)O3 relaxor ferroelectric ceramics

Since recently, lead-free dielectric ceramics have garnered significant interest for their high-power density and rapid charge-discharge capabilities. Nonetheless, their practical application is still limited by relatively low energy storage density and efficiency. To address this issue, a new class of relaxor ferroelectric ceramics ((1-x)(Bi0.5Na0.5)0.7Sr0.3TiO3-xCa(Nb0.5Al0.5)O3, with x from 0.00 to 0.16) was formulated and synthesized in the present work using a solid-state reaction method. Special attention was paid to the effect of multiscale structure regulation on the energy storage properties of the ceramics. All ceramics exhibited the relaxor characteristics, which increased with the added content of Ca(Nb0.5Al0.5)O3 (CNA). Significant achievements have been made in multi-scale regulation of energy storage characteristics of these ceramics. In particular, the ultrahigh energy storage density and efficiency (10.15 J/cm3 and 86.2 %, respectively) were realized in the ceramic with x = 0.14. This optimized composition also displayed good temperature stability at 20–140 °C and excellent frequency stability in the range of 1–200 Hz. Furthermore, the outstanding charge and discharge characteristics (current density CD, power density PD, and discharge time t0.9 of 1257 A/cm2, 377 MW/cm3, and 45.8 ns, respectively) were obtained. The experimental study, finite element analysis, and first-principles calculations confirmed that the multiscale features, such as nano-scale domains, large band gap, and small grain size, promoted by the addition of CNA, are all beneficial for the improvement of energy storage performance, opening up new prospects in the application of advanced dielectric capacitors.

Achieving ultrahigh energy density and efficiency simultaneously in (Na, K)NbO3-based lead-free relaxor ferroelectrics via a collaborative design

Relaxor ferroelectrics have garnered enormous attention for their great application potential in pulsed power energy-storage capacitors, while simultaneously achieving large recoverable energy density (Wrec) and high efficiency (η) remains a formidable challenge. Through collaboratively controlling multiscale structure via a combination of composition design and processing improvement, polar nanodomains with multiple local symmetries were engineered in ultrafine grains, enabling significantly reduced polarization hysteresis, delayed saturation polarization, maintained high polarization, and enhanced breakdown strength. As a result, an excellent comprehensive energy-storage performance of Wrec ∼11.8 J/cm3 and η ∼88.7 % is achieved in the (Na, K)NbO3-based spark-plasma-sintered lead-free ceramics, together with stable charge-discharge properties of power density ∼176.3 MW/cm3, discharge energy density ∼3.2 J/cm3, and discharge time ∼43 ns over a wide temperature range of 20–140 °C. The studied ceramic demonstrates great advantages in advanced capacitive energy-storage applications.

Regulating the switching electric field and energy-storage performance in antiferroelectric ceramics via heterogeneous laminated engineering

Antiferroelectric (AFE) ceramics with near-zero remanent polarization originating from unique electric field-induced antiferroelectric-ferroelectric phase transition are of great importance for the application in the energy-storage devices. However, achieving the most widely optimized switching electric field and energy-storage performance of antiferroelectric ceramics has predominantly relied on A/B-site ion doping strategies, often accomplished through a series of experimental and analytical works. In this context, we propose a novel strategy of heterogeneous laminated engineering as a substitute for A/B-site ion doping. This approach allows for a more intuitive regulation of the switching electric field and energy-storage performance in antiferroelectric ceramics without the need for complicated workload. Namely, the ferroelectric Pb0.99(Nb0.9Ta0.1)0.2(Zr0.9Sn0.1)0.8O3 (PNTZS) and antiferroelectric (Pb0.875La0.05Sr0.05) (Zr0.7Sn0.3)O3 (PLSZS) were layer-by-layer laminated using a tape-casting technique. All heterogeneous laminated ceramics exhibit antiferroelectric characteristics, and the magnitude of the switching electric field can be controlled by regulating the ratio between PNTZS and PLSZS. Furthermore, the finite element simulation revealed differences in the local electric fields between PNTZS and PLSZS in heterogeneous laminated ceramics, resulting in a win-win situation for both polarization and the breakdown strength. A large recoverable energy density of 11.2 J cm−3 with ultrahigh energy efficiency of 94.2 % can be obtained under 56 kV mm−1. Moreover, the energy storage performance shows no obvious deterioration in a broad frequency range (1–100 Hz) and temperature range (25–120 °C). Particularly, the outstanding discharge properties with a large discharge energy density of 7.1 J cm−3 and a high power density of 263.7 MW cm−3 show great potential for energy-storage applications. To conclude, a new strategy is opened up herein for designing antiferroelectric energy storage materials, showing the great application potential in the pulse power devices.

Multifunction integration within magnetic CNT-bridged MXene/CoNi based phase change materials

Developing advanced nanocomposite phase change materials (PCMs) integrating zero-energy thermal management, microwave absorption, photothermal therapy and electrical signal detection can promote the leapfrog development of flexible wearable electronic devices. For this goal, we propose a multidimensional collaborative strategy combining two-dimensional (2D) MXene nanosheets with metal-organic framework-derived one-dimensional (1D) carbon nanotubes (CNTs) and zero-dimensional (0D) metal nanoparticles. After encapsulating paraffin wax (PW) in three-dimensional (3D) networked multidimensional MXene/CoNi–C, the resulting composite PCMs exhibit excellent thermal energy storage capacity and long-term thermally reliable stability. Benefiting from the synergistically enhanced photothermal effects of CNTs, Co/Ni nanoparticles and MXene, PW@MXene/CoNi–C can capture photons efficiently and transfer phonons quickly, yielding an ultrahigh photothermal conversion and storage efficiency of 97.5%. Additionally, PW@MXene/CoNi–C composite PCMs exhibit high microwave absorption with a minimum reflection loss of −49.3 ​dB at 8.03 ​GHz in heat-related electronic application scenarios. More attractively, the corresponding flexible phase change film can simultaneously achieve thermal management and electromagnetic shielding of electronic devices, as well as photothermal therapy and electrical signal detection for individuals. This functional integration design provides an important reference for developing advanced flexible multifunctional wearable materials and devices.

Polyethylene glycol/melamine foam composite phase change materials modified by CdS/Ag exhibits high photothermal conversion performance

CdS has been shown to be an excellent photon trap with strong absorption of light at visible and near-infrared wavelengths. The use of CdS for phase change material (PCM) modification can significantly improve its photothermal conversion performance. However, due to the unique energy band structure of CdS, the difficulty in electron conduction leads to poor thermal conductivity. This problem can be improved by introducing high thermal conductivity nanometals for modification, however, the effective combination of CdS and nanometals has been challenging. In this study, a new preparation strategy is demonstrated, in which Ag nanoparticles (NPs) with similar lattice parameters and crystalline coordination to CdS is first introduced on the surface of carbonized melamine foam (CMF), followed by the introduction of CdS NPs. This similar structure helps to form a better interfacial bond between CdS and Ag. The resulting stabilized structure enables the composite phase change material (CPCM) to achieve 96.1 % PEG loading with an ultra-high photothermal conversion efficiency of 94.6 %, thermal conductivity of 0.61 W/m∙K, and excellent antimicrobial activity. This study provides valuable guidance for the engineering design of CPCM with high photothermal conversion performance and suggests its practical application value in seawater evaporation and thermal management of medical devices.

Low-Coordinated Conductive ZnCu Metal-Organic Frameworks for Highly Selective H2O2 Electrosynthesis.

Direct electrosynthesis of hydrogen peroxide (H2O2) with high production rate and high selectivity through the two-electron oxygen reduction reaction (2e-ORR) offers a sustainable alternative to the energy-intensive anthraquinone technology but remains a challenge. Herein, a low-coordinated, 2Dconductive Zn/Cu metal-organic framework supported on hollow nanocube structures (ZnCu-MOF (H)) is rationally designed and synthesized. The as-prepared ZnCu-MOF (H) catalyst exhibits substantially boosted electrocatalytic kinetics, enhanced H2O2 selectivity, and ultra-high Faradaic efficiency for 2e-ORR process in both alkaline and neutral conditions. Electrochemical measurements, operando/quasi in situ spectroscopy, and theoretical calculation demonstrate that the introduction of Cu atoms with low-coordinated structures induces the transformation of active sites, resulting in the beneficial electron transfer and the optimized energy barrier, thereby improving the electrocatalytic activity and selectivity.

An Atmospheric Water-Harvester with Ultrahigh Uptake-Release Efficiency at Low Humidity.

Atmospheric water harvesting is a practical strategy that is achieved by removing materials from air moisture to relieve global water scarcity. Here we design a water-harvester (i.e., MOF-303/thiolated polymer composite (MTC)) by using a metal-organic framework (MOF-303) and thiolated chitosan (TC) skeleton. Intermolecular hydrogen bonding between TC and MOF-303 facilitates porous structures with enlarged air-polymer interfaces for long cycling life and high capacity at low relative humidity. Benefiting from synergetic effects on porosity and anchorage for accelerating the uptake-release of moisture, MTC exhibits a rapid water uptake capacity of 0.135 g/g in 60 min under 12.5 RH% and ultrafast water desorption kinetics of 0.003 g/g/min at 8.5 RH%, which is superior to the as-reported MOF-303 based adsorbents. At low heat (∼40 °C), the water desorption and collection rate, respectively, are 0.0195 and 0.0168 g/g/min within 210 min, showing ultrahigh harvesting efficiency. These results highlight the enormous potential as promising materials for solving the world's water scarcity crisis. This study offers an insight into the design of AWH materials, which can be extended into applications in some realms, e.g., freshwater development for industry in arid areas, water engineering-related devices and systems, etc.

Sandwich-structured SrTiO3/PEI composite films with high-temperature energy storage performance

Dielectric capacitors are widely used in aerospace and power systems due to their non-polluting, high power density and fast charge/discharge rates. Polyetherimide (PEI) exhibits excellent temperature tolerance, high withstand voltage and low dielectric loss. However, its relatively low dielectric constant restricts its energy storage density. In this paper, a sandwich-structured composite film with the outer layer of pure PEI and the middle layer of strontium titanate (SrTiO3)/PEI is prepared by the solution casting method. At room temperature, the composite film with 5 vol% two-dimensional (2D) SrTiO3 plates achieves an outstanding energy storage density of 19.46 J cm−3 and an ultra-high energy storage efficiency of 97.05% under an electric field of 630 MV m−1. Furthermore, this composite film exhibits a maximum energy storage density of 10.34 J cm−3 and an energy storage efficiency of 88.13% at 150 °C. Combined with finite element simulation results, it confirms that the synergistic effect of 2D SrTiO3 plates and sandwich-structured can effectively hinder the development of electric trees. This work presents a sophisticated approach to design and preparation of dielectric composites suitable for the applications of high-temperature energy storage.