Search

AgNbO3 (AN)-based lead-free antiferroelectric ceramics are widely studied for their use as dielectric capacitor materials. In this study, Eu3+-doped AN ceramics were prepared and the results show that Eu3+ diffused into the AN lattice. The ceramics were formed by M1 and M2 phases coexisting at room temperature, as distinct from the M1 (M: monoclinic) phase of pure AN. Electrical properties and structural characterization showed that the antiferroelectric stability of the ceramics increases with the increase in Eu3+ levels. At room temperature, Ag0.94Eu0.02NbO3 ceramic exhibited a good energy storage density of 5.3 J/cm3 and a high efficiency of 71.9%. When the temperature rises from room temperature to 140 °C, the efficiency of the sample decreases from 80.4% to 67.1% and Wr decreases from 2.1 to 2.0 J/cm3, which indicates that the sample has good temperature stability. The time constant (t0.9) of this sample was less than 60 ns and the power density (PD) was 51.3 MW/cm3, indicating excellent charge–discharge capabilities. This novel ceramic is expected to be used as a new dielectric capacitor material for pulsed power supplies. [ABSTRACT FROM AUTHOR]

Dielectric capacitors prepared by antiferroelectric (AFE) materials have the advantages of large power density and fast discharge ability. It has been a focus on the improvement of the recoverable energy density (Wrec) and discharge energy–density (Wdis) in the AFE ceramics. To address the above issue, optimizing the proportion of components is proposed for enhancing ceramic antiferroelectricity, ultimately improving the breakdown strength (Eb) and Wrec. In this work, an ultrahigh Wrec (14.3 J/cm3) with an excellent energy efficiency (η) of 81.1% is obtained in (Pb0.96Sr0.02La0.02)(Hf0.9Sn0.1)O3 AFE ceramic at electric field of 490 kV/cm, which is the maximum value reported in lead-based AFE ceramics fabricated by the conventional solid-state reaction method so far. The multistage phase transition induced by the electric field is observed in the polarization–electric field (P–E) hysteresis loops. Furthermore, an outstanding power density (PD) of 335 MW/cm3 and an excellent Wdis of 8.97 J/cm3 with a rapid discharge speed (102 ns) are obtained at electric field of 390 kV/cm. In addition, (Pb0.96Sr0.02La0.02)(Hf0.9Sn0.1)O3 ceramics also possess an excellent thermal and frequency stability. These exceptional properties indicate that (Pb0.98−xSrxLa0.02)(Hf0.9Sn0.1)O3 ceramics are a potential candidate for pulsed power devices and power electronic devices. [ABSTRACT FROM AUTHOR]

In this study, we present a novel low-frequency magnetic field energy harvester (EH) employing beryllium bronze/Pb(Zr,Ti)O3 ceramic composited dual-beam structures with tip magnets attached to the inner and outer beams. This design incorporates the internal magnetic-coupled (IMC) effect, resulting in significantly enhanced coupling ability and a wide bandwidth. The validity of the IMC mechanism is confirmed through theoretical formulas and numerical simulations. By leveraging the IMC condition, the EH achieves an expanded bandwidth, which increases from 22 to 43 Hz. Moreover, the total output voltages at the inherent resonance and internal resonance are boosted by 15.4% and 32%, respectively. The performance of the IMC-EH can be further improved by increasing the number of the endmost magnets. Experimental investigations reveal that the IMC-EH generates a maximum RMS output power density of 56.25 μW Oe−2 cm−3, surpassing existing magnetically coupled piezoelectric energy harvesters. Remarkably, even under an ambient magnetic field as low as 1 Oe, the proposed IMC-EH still yields a total output power of 185 μW, sufficient to continuously power 26 LEDs in real time. This demonstrates its potential as a promising solution for low-power consumption small electronics. Furthermore, the implications of this work extend beyond its immediate benefits, as it inspires the design of future self-powered wireless sensor networks in the context of the Internet of Things. [ABSTRACT FROM AUTHOR]

In this paper, an ultra-thin metamaterial absorber (UMA) in the S-band is designed. The overall structure adopts a three-layer design. The top layer is a magnetic material, and the middle layer of the UMA is composed of a centrally symmetrical open square ring (four edges are opened) and a circular pattern placed at the center, which is etched on the FR4 dielectric substrate by printed circuit board technology. The absorptivity of the absorber is more than 90% in 1.73–4.04 GHz under normal incidence, and the fractional bandwidth is 80.1%. The total thickness of the absorber is about 3.4 mm, corresponding to 0.02 λ L at the lowest operating frequency. Moreover, it also has good polarization insensitivity and wide-angle incident characteristics. The absorption mechanism of the UMA is analyzed from the aspects of power loss density and surface current. Finally, a sample was fabricated and measured. The measured results are in good agreement with the simulation results, which verifies the effectiveness of the design method. [ABSTRACT FROM AUTHOR]

Cytoskeletal gels are engineered prototypes that mimic the contractile behavior of a cell in vitro. They are composed of an active polymer matrix and a liquid solvent. Their contraction kinetics is governed by two dynamic phenomena: mechanotransduction (molecular motor activation) and solvent diffusion. In this paper, we solve the transient problem for the simple case of a thin gel slab in uniaxial contraction under two extreme conditions: motor-limited or slow motor (SM) activation regime, and diffusion-limited or fast motor (FM) activation regime. The former occurs when diffusion is much faster than mechanotransduction, while the latter occurs in the opposite case. We observe that in the SM regime, the contraction time scales as t / t 0 ∼ (λ / λ 0) − 3 , with t 0 being the nominal contraction time, and λ and λ 0 being the final and initial stretches of the slab. t 0 is proportional to 1 / w ˙ , where w ˙ is the average mechanical power generated by the molecular motors per unit reference (dry polymer) volume. In the FM regime, the contraction time scales as t / t 1 ∼ (1 − λ / λ 0) 2 , with t 1 being the nominal contraction time, here proportional to the ratio L 2 / D , where L is the reference (dry polymer) thickness, and D is the diffusivity of the solvent in the gel. The transition between the SM and FM regimes is defined by a characteristic power density w ˙ ∗ , where w ˙ ≪ w ˙ ∗ gives the SM regime and w ˙ ≫ w ˙ ∗ gives the FM regime. Intuitively, w ˙ ∗ is proportional to D / L 2 , where, at a given power density w ˙ , a thinner gel slab (smaller L) or including smaller solvent molecules (higher D) is more likely to be in the SM regime given that solvent diffusion will occur faster than motor activation. [ABSTRACT FROM AUTHOR]

Dielectric energy storage capacitors offer great potential in pulsed power devices due to the high power density and fast charging-discharging rate. Designing a host material with high field-induced polarization is of importance for developing dielectric energy storage materials via further composition modulation. In this paper, we compare the microstructure, dielectric, and ferroelectric properties as well as the energy storage performance of samples K1/2Bi1/2TiO3(KBT), 75KBT-25BiFeO3 (KBTF25), and 88KBT-12Bi0.85Nd0.15FeO3 (KBNTF12) in detail. It is found that, among three samples, sample KBNTF12 possesses the most complex local structure coexisting of a four-distortions with different polarities; meanwhile, sample KBNTF12 behaves as a strong relaxor, thus giving a high field-induced polarization. Besides, sample KBNTF12 realizes the highest electric breakdown strength Eb among three samples, which is resorted to the highest resistivity of grain boundary. Highest ΔP and Eb of sample KBNTF12 among three samples render it achieve ultrahigh stored energy density Ws of 6.94 J/cm3, high recoverable energy density Wr of 5.23 J/cm3, and high efficiency η of 75.4%. Our work suggests that 88KBT-12BNF binary composition be an optimal candidate for dielectric energy storage ceramics. [ABSTRACT FROM AUTHOR]

This work is devoted to finding the optimal parameters of the HgTe/CdHgTe multi-quantum-well structure for the generation of two-dimensional plasmon-phonons under optical excitation. It is shown that a decrease in the bandgap and an increase in the number of quantum wells lead to two consequences. The first is a decrease in the nonequilibrium carrier threshold concentration and the threshold power density of optical excitation required for the plasmon-phonon gain. The second is a significant (tens of times) decrease in the effective refractive index of the generated plasmon-phonons, which improves the output of the plasmon-phonon radiation from the edge of the structure. The value of the optimal bandgap and the optimal number of quantum wells in the structure for plasmon-phonon gain are discussed. [ABSTRACT FROM AUTHOR]

The direct conversion of thermal energy into electrical current via thermoelectric (TE) effects relies on the successful integration of efficient TE materials into thermoelectric generators (TEGs) with optimized characteristics to ensure either optimum output power density or conversion efficiency. Successfully employed for powering deep-space probes and extraterrestrial rovers since the 1960s, the development of this technology for waste-heat-harvesting applications faces several key issues related to the high temperatures and oxidizing conditions these devices are subjected to. This Perspective provides a brief overview of some prospective thermoelectric materials/technologies for use in radioisotope thermoelectric generators utilized in space missions and highlights the progress made in the field over the last years in the fabrication of TEGs. In particular, we emphasize recent developments that enable to achieve increased power densities, thereby opening up novel research directions for mid-range-temperature applications. In addition to showing how using lower quantities of TE materials may be achieved without sacrificing device performance, we provide an outlook of the challenges and open questions that remain to be addressed to make this technology economically and technologically viable in everyday-life environments. [ABSTRACT FROM AUTHOR]

To maximize the capabilities of minimally invasive implantable bioelectronic devices, we must deliver large amounts of power to small implants; however, as devices are made smaller, it becomes more difficult to transfer large amounts of power without a wired connection. Indeed, recent work has explored creative wireless power transfer (WPT) approaches to maximize power density [the amount of power transferred divided by receiver footprint area (length × width)]. Here, we analyzed a model for WPT using magnetoelectric (ME) materials that convert an alternating magnetic field into an alternating voltage. With this model, we identify the parameters that impact WPT efficiency and optimize the power density. We find that improvements in adhesion between the laminated ME layers, clamping, and selection of material thicknesses lead to a power density of 3.1 mW/mm2, which is over four times larger than previously reported for mm-sized wireless bioelectronic implants at a depth of 1 cm or more in tissue. This improved power density allows us to deliver 31 and 56 mW to 10 and 27-mm2 ME receivers, respectively. This total power delivery is over five times larger than similarly sized bioelectronic devices powered by radiofrequency electromagnetic waves, inductive coupling, ultrasound, light, capacitive coupling, or previously reported magnetoelectrics. This increased power density opens the door to more power-intensive bioelectronic applications that have previously been inaccessible using mm-sized battery-free devices. [ABSTRACT FROM AUTHOR]

Numerical calculations and experimental approaches are used to examine the slip characteristics of 1064 nm laser ablated single crystal germanium. The ablation and cooling processes are used to investigate the influence of laser power density on the creation of the slip process. A 1064 nm continuous laser and a nanosecond laser were used to ablate single-crystal germanium samples, and the damage to the surface was seen using an optical microscope. The results demonstrate that raising the laser power density to 107 W/cm2 efficiently suppresses slip production during laser processing. [ABSTRACT FROM AUTHOR]

Controllable tuning of electron–phonon coupling strength and excited state dynamics is important for the understanding of resonance Raman scattering in low-dimensional semiconductors. Here, we report a significant and reversible field-induced modulation in absolute resonance Raman intensity of quantum dots using ionic liquid gating. Meanwhile, a potential-dependent nonlinear relationship is present between Raman intensity and excitation power density. By exploring the parameter space within a time domain model, we find that the Raman intensity variation is mainly determined by the homogeneous linewidth. We further propose that the Fermi level positions and exciton species play key roles in the excited state decay rates. [ABSTRACT FROM AUTHOR]

A multiscale nanoengineering strategy, simultaneously including metal nanoparticle-atomized pathway and metal-organic framework-derived approach, is developed to realize the anchoring of atomic and nanosized transition-metal species in N-doped hierarchically tubular porous carbon for high-performance oxygen reduction and evolution reactions. [Display omitted] • A multiscale nanoengineering strategy, simultaneously including metal-organic framework-derived approach and metal nanoparticle-atomized pathway, to realize the anchoring of atomic and nanosized Fe/Co species on N-doped hierarchically tubular porous carbon substrate. • Fe/Co nanoparticles and single atoms are respectively utilized for accelerating OER and ORR, endowing the obtained material with a small OER/ORR potential gap of 0.684 V. • When the obtained material is used in the air electrode, 260 mW cm-2 of peak power density for liquid-state Zn-air battery, 110 mW cm-2 of peak power density for solid-state Zn-air battery, and 1000 charge-discharge cycles without decay are realized. The development of cost-effective, high-activity and stable catalysts to accelerate the sluggish kinetics of cathodic oxygen reduction/evolution reactions (ORR/OER) plays a critical part in commercialization application of rechargeable Zn-air batteries (RZABs). Herein, a multiscale nanoengineering strategy is developed to simultaneously stabilize Co-doped Fe nanoparticles originated from metal-organic framework-derived approach and atomic Fe/Co sites derived from metal nanoparticle-atomized way on N-doped hierarchically tubular porous carbon substrate. Thereinto, metal nanoparticles and single atoms are respectively used to expedite the OER and ORR. Consequently, the final material is acted as an oxygen electrode catalyst, displaying 0.684 V of OER/ORR potential gap, 260 mW cm-2 of peak power density for liquid-state RZAB, 110 mW cm-2 of peak power density for solid-state RZAB, and 1000 charge-discharge cycles without decay, which confirms great potential for energy storage and conversion applications. [ABSTRACT FROM AUTHOR]

[Display omitted] Although lots of nanomaterials modified anodes have been reported to improve the bacterial attachment and extracellular electron transfer (EET) in microbial fuel cells (MFCs), the lack of a three dimensional (3D) conductive and capacitive network severely limited MFCs performance. In this work, 3D conductive networks derived from mucor mycelia were grown on carbon cloth (CC), and capacitive FeMn phosphides/oxides were further anchored on these 3D networks by electrochemical deposition (denoted as FeMn/CMM@CC) to simultaneously address the above challenges. As a result, the multivalent metal active sites were evenly distributed on 3D conductive network, which favored the enrichment of exoelectrogens, mass transport and EET. Consequently, the as-prepared FeMn/CMM@CC anode displayed accumulated charge of 131.4C/m2, higher than bare CC. Meanwhile, FeMn/CMM@CC anode substantially promoted flavin excretion and the amounts of nano conduits. The abundance of Geobacter was 63 % on bare CC, and greatly increased to 83 % on FeMn/CMM@CC. MFCs equipped by FeMn/CMM@CC anode presented the power density of 3.06 W/m2 and coulombic efficiency (29.9 %), evidently higher than bare CC (1.29 W/m2, 7.3 %), and the daily chemical oxygen demand (COD) removal amount also increased to 92.6 mg/L/d. This work developed a facile method to optimize the abiotic-biotic interface by introducing 3D conductive and capacitive network, which was proved to be a promising strategy to modify macro-porous electrodes. [ABSTRACT FROM AUTHOR]

The interpenetrating polymer networks PVA-SA-PPy hydrogels were prepared by the freeze-thawing and in-situ polymerization method. The PVA network and SA network formed interpenetrating networks through hydrogen bonding and physical entanglement, which boosted the mechanical properties and ion diffusion characteristics. [Display omitted] Flexible supercapacitors (FSCs) have attracted much attention due to their strong mechanical flexibility, wearability and portability, which greatly rely on the employed flexible electrodes. The conductive polymer hydrogels with excellent flexibility, processability and capacitive performance are one of the most promising candidates, which are still limited by their poor mechanical properties. Constructing robust interpenetrating polymer networks (IPN) is an effective approach to promote their mechanical properties. Herein, interpenetrating polyvinyl alcohol (PVA)-sodium alginate (SA)-polypyrrole (PPy) hydrogels are prepared by the freeze–thaw and in-situ polymerization method. The IPN structure composed of PVA and SA not only enhances the mechanical properties of hydrogels, but also provides substantial active sites for electrochemical reactions. Moreover, the hydrogen-bonding interaction between different components in the PVA-SA-PPy hydrogel boosts the charge/ion transfer. The optimal PVA-SA-PPy hydrogels show an elongation at break of 380 %, a tensile strength of 1.5 MPa, and a specific capacitance of 2646 mF cm−2 at 2 mA cm−2. The symmetric PVA-SA-PPy FSCs show an energy density of 96.7 μWh cm−2 at a power density of 999.9 μW cm−2, and the capacitance retention is 66.3 % after 10,000 cycles. These exceptional mechanical and electrochemical properties make the PVA-SA-PPy hydrogels a promising candidate for FSCs. [ABSTRACT FROM AUTHOR]

A high performance lamellar structured Fe-doped MnS/graphene anode has been developed for sodium-ion storage. Due to the synergistic positive effect of graphene confinement, strong Mn S C bonding and Fe-doping, the composite exhibits excellent rate performance and long-term stability. A prototype sodium-ion capacitor fabricated with Fe-MnS/PG anode and nitrogen-doped carbon cathode can deliver both high energy and high power densities. [Display omitted] Manganese sulfide (MnS) is a promising converion-type anode for sodium storage, owing to the virtues of high theoretical capacity, coupled with it crustal abundance and cost-effectiveness. Nevertheless, MnS suffers from inadequate electronic conductivity, sluggish Na+ reaction kinetics and considerable volume variation during discharge/charge process, thereby impeding its rate capability and capacity retention. Herein, a novel lamellar heterostructured composite of Fe-doped MnS nanoparticles/positively charged reduced graphene oxide (Fe-MnS/PG) was synthesized to overcome these issues. The Fe-doping can accelerate the ion/electron transfer, endowing fast electrochemical kinetics of MnS. Meanwhile, the graphene space confinement with strong Mn S C bond interactions can facilite the interfacial electron transfer, hamper volume expansion and aggregation of MnS nanoparticles, stabilizing the structural integrity, thus improving the Na+ storage reversibility and cyclic stability. Combining the synergistic effect of Fe-doping and space confinement with strong Mn S C bond interactions, the as-produced Fe-MnS/PG anode presents a remarkable capacity of 567 mAh/g at 0.1 A/g and outstanding rate performance (192 mAh/g at 10 A/g). Meanwhile, the as-assembled sodium-ion capacitor (SIC) can yield a high energy density of 119 Wh kg−1 and a maximum power density of 17500 W kg−1, with capacity retention of 77 % at 1 A/g after 5000 cycles. This work offers a promising strategy to develop MnS-based practical SICs with high energy and long lifespan, and paves the way for fabricating advanced anode materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Use of a university two-step strategy to construct 3D VO 2 /CNT@PANI with core–shell architecture. • Taking full advantage of the synergistic effect, the optimal VO 2 /CNT@PANI exhibits superior electrochemical performances. • Fabrication of a full-printable in-planar symmetric supercapacitor with a remarkable areal energy density and cycling life. • Great potential application prospects in the field of portable/wearable electronics. As a progressive electronic energy storage device, the flexible supercapacitor holds tremendous promise for powering wearable/portable electronic products. Of various pseudocapacitor materials, vanadium dioxide (VO 2) has garnered extensive attention due to its impressive theoretical capacitance. However, the challenges of inferior cycling life and lower energy density to be addressed. Herein, we prepare VO 2 nanorods with winding carbon nanotubes (CNT) via a facile solvothermal route, followed by in situ polymerization of polyaniline (PANI) shell. Taking full advantage of the synergistic effect, the VO 2 /CNT@PANI composite delivers a high specific capacitance of 354.2F/g at 0.5 A/g and a long cycling life of ∼ 88.2 % over 5000 cycles resulting from the enhanced conductivity of CNT and stabilization of PANI shell. By screen printing the formulated inks with outstanding rheological behaviours, we manufacture an in-planar VO 2 /CNT@PANI symmetric supercapacitor (VO 2 /CNT@PANI SSC) device featuring an orderly arrangement structure. This device yields a remarkable areal energy density of 99.57 μWh/cm2 at a power density of 387.5 μW/cm2 while retaining approximately ∼ 87.6 % of its initial capacitance after prolonged use. Furthermore, we successfully powered a portable game machine for more than 2 min using two SSCs connected in series with ease. Therefore, this work presents a universal strategy that utilises combination and coating to boost electrochemical performance for flexible high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

The operating parameters of proton exchange membrane fuel cell (PEMFC) are critical to its performance and working life. This study presents a data-driven modeling approach combining a surrogate model with the particle swarm optimization algorithm to optimize operating parameters for PEMFC and obtain the maximum power density. The results show that the operating parameters significantly influence power density under high current densities, with inlet temperature having the most significant effect. Lower inlet temperature, relative humidity in the cathode and anode, along with higher operating pressure yield improved output performance. The Genetic Algorithm-Backpropagation Neural Network based surrogate model exhibits excellent predictive performance with correlation coefficients of 0.99896 and 0.99815 for the training and test sets, respectively. Optimized conditions achieve a 3.3% increase in power density compared to initial settings, with only a 0.15% error in simulation calculations. This data-driven approach provides valuable insights for maximizing PEMFC efficiency and performance. • An approach combining surrogate model with PSO algorithm to predict PEMFC performance is proposed. • The GA-BP-based surrogate model exhibits excellent predictive performance. • Maximum power density and corresponding operating parameters are achieved. [ABSTRACT FROM AUTHOR]

Terahertz waveguides and resonators have brought numerous applications from biomedical to modern communications. In this paper, we have demonstrated numerically a straight semiconductor-insulator-semiconductor(SIS) waveguide attached to a split ring resonator, which acts as a terahertz frequency filter and can be used for refractive index sensing. The device's transmission properties have been studied using the finite element method. To fix the third dimension of the device, that is the depth of the waveguide the effective mode index and power density calculations are done for the propagating mode. The frequency tuning of the filter is achieved by changing the geometric parameters of the waveguide and resonator system such as ring radii and split width. Both the symmetric and antisymmetric modes of the split ring show almost the same rate of change of resonance frequency with the change in geometric parameters. To demonstrate the importance of the split position, the transmittance is studied by placing the split at different positions on the ring. We obtained the same transmittance for the split at left and right positions, whereas the split at the top and bottom shows different transmittance similar to the transmittance of a ring resonator. The symmetric and antisymmetric modes of the split ring are calculated for refractive index sensing and the highest sensitivity of 0.741 THz/ refractive index unit (RIU) for the symmetric mode as expected. [ABSTRACT FROM AUTHOR]

In this study, we introduce an effective strategy to prepare electrodes containing new nanocomposites with high specific capacity. This research led to the preparation of CoFe2‐xCexO4/rGO‐Pani nanocomposite with an extraordinary specific capacitance of 3257.83 F·g−1 (at 10 mV·s−1), a power density of 349.951 W/kg, and an energy density of 3.52 Wh/kg. Also, electrical conductivity studies for new nanocomposite showed good electrical conductivity and better semiconducting properties compared with its similar compounds. Also, the synthesized compounds were characterized and identified by other analyses. FT‐IR analysis for reduced graphene oxide showed that graphene oxide was well reduced. It also confirmed the presence of Ce‐O for both CoFe2‐xCexO4/rGO‐Pani and CoFe2O4‐CeO2/rGO‐Pani magnetic nanocomposites. XRD analysis confirmed the crystal structure for rGO, CoFe2‐xCexO4/rGO‐Pani, and CoFe2O4‐CeO2/rGO‐Pani. VSM analysis was done to check the magnetic properties of the nanocomposite, and the magnetic values were measured as expected. In the following, morphological studies and the uniformity of distribution of elements in magnetic nanocomposite were carried out with FE‐SEM and Map, respectively. [ABSTRACT FROM AUTHOR]

In this paper, a control method combined with variable frequency and phase shifting is proposed, the primary purpose of which is to optimize the operating efficiency of the phase‐shift full‐bridge (PSFB) DC‐DC converter. By modeling the losses of the PSFB converter, the optimal switching frequency related to the load conditions is found. A neural network aided variable frequency controller that can work linearly is built to achieve the proposed method. At the same time, the voltage control loop is retained to ensure the stability of the output voltage and the necessary dynamic response of the converter. This paper builds an experimental platform for a 2 kW PSFB DC‐DC converter to verify the effectiveness of the proposed control method. With the control method proposed in this paper, the PSFB converter can always work at the optimum efficiency point under different load conditions. In addition, this paper also analyzes the influence of variable frequency control on PSFB operating states, such as zero‐voltage‐switching (ZVS) constraints, continuous conduction mode (CCM) operating states, and power density, which have an impact on its operating conditions. [ABSTRACT FROM AUTHOR]

This paper presents a new method for the layered equivalent modeling of slot winding in the stator of a flat wire motor to accurately study the thermal performance under steady-state conditions. The conventional equivalent model for flat wire winding involves treating the slot winding as a single copper rod for temperature analysis. This method is not applicable to flat wire motors under high-power density operating conditions. As the power density of the motor increases, the flat wire winding is more affected by skin effect and proximity effect, resulting in a sharp increase in AC loss and uneven distribution of losses in the slot winding. The conductor losses are highest near the slot opening, a characteristic that conventional model is unable to reflect. The proposed layered modeling method fully takes into account the characteristics of flat wire winding. This method involves adding interlayer insulation to divide the overall modeled conductor into layers and fully considers the thermal parameters, heat transfer characteristics, and distribution of materials within the slot to establish a new equivalent model for flat wire winding. Finally, the comparison of the results with the actual model and experimental tests demonstrates that this method effectively improves the calculation accuracy by 2.2% of the flat wire winding equivalent model. [ABSTRACT FROM AUTHOR]

Nanourchin VO2 nanostructures have been effectively synthesized by hydrothermal method. The synthesized hierarchical nanostructure has been characterized by various characterization techniques and electrochemical behaviour has been studied. X-ray diffraction analysis revealed the monoclinic phase and morphological analysis (FESEM) of VO2 showed nanourchin-like structure with arrangement of various nanorods in radial fashion. Over these nanorods, formation of secondary growth of asterisk-shape structure was observed. The width and length of nanorods were ~ 50 and ~ 75 nm, respectively. For the electrochemical measurements, 2032 type coin cells were fabricated using VO2 as electrode material. The electrochemical study of VO2 exhibited the pseudocapacitive behaviour with specific capacitance of 44 F g−1 in organic electrolyte with symmetric capacitor of two electrode system. The maximum energy density and power density were 44 and 8635 Wh kg−1, respectively. Cycling performance exhibited symmetric charge–discharge curves, and also specific capacitance was maintained up to 82% of initial value. [ABSTRACT FROM AUTHOR]

[Display omitted] Utilizing diverse material combinations in heterogeneous structures has become an effective approach for regulating interface characteristics and electronic structures. The g-C 3 N 4 /Co 3 O 4 heterostructures were fabricated by uniformly modifying Co 3 O 4 nanoparticles onto discrete clusters of g-C 3 N 4 nanosheets. Then, they were subsequently employed as positive electrode materials for assembling hybrid supercapacitors. According to the first-principles calculation, Co 3 O 4 and g-C 3 N 4 formed Co-N ionic bonds, establishing interfacial space symmetry-broken heterojunction and direct exchange and superexchange between ions at the interface and sub-interface. This resulted in a high-density spin–orbit hybrid heterogeneous polarization interface, significantly improving the quantum capacitance of heterojunction materials. Experimental results showed that the heterojunction had a specific capacitance of 2662 F g−1 at 1 A g−1. When the power density was 750 W kg−1, the energy density reached 128 Wh kg−1. Even when the power density was 16850 W kg−1, it could show an energy density of 62.5 Wh kg−1. The g-C 3 N 4 /Co 3 O 4 heterojunction could realize high energy density charge storage as the cathode material of supercapacitors. The construction of heterogeneous polarization interfaces for high-energy quantum capacitors provides a new and effective method for the energy storage field. [ABSTRACT FROM AUTHOR]

As a high-efficiency electrocatalyst for NH 3 production via NO 2 − reduction, Mo-doped Co 3 O 4 nanoarray exhibits an extremely high Faradaic efficiency of 96.9 % and a corresponding NH 3 yield of up to 651.5 μmol/h cm−2 at −0.5 V. [Display omitted] • Mo-doped Co 3 O 4 nanoarray on titanium mesh is synthesized as an effective catalyst for NO 2 −-to-NH 3 conversion. • Mo-Co 3 O 4 /TM exhibits a high NH 3 Faradaic efficiency of 96.9 % and a related yield of 651.5 μmol h−1 cm−2 with strong stability. • DFT calculations reveal the catalytic mechanism of NO 2 −RR on Mo-Co 3 O 4. • The fabricated Zn-NO 2 − battery achieves a peak power density of 3.6 mW cm−2 and a satisfactory NH 3 yield of 108.4 μmol h−1 cm−2. Electrochemical conversion of nitrite (NO 2 −) contaminant to green ammonia (NH 3) is a promising approach to achieve the nitrogen cycle. The slow kinetics of the complex multi-reaction process remains a serious issue, and there is still a need to design highly effective and selective catalysts. Herein, we report that molybdenum doped cobalt oxide nanoarray on titanium mesh (Mo-Co 3 O 4 /TM) acts as a catalyst to facilitate electroreduction of NO 2 − to NH 3. Such a catalyst delivers an extremely high Faradaic efficiency of 96.9 % and a corresponding NH 3 yield of 651.5 μmol h−1 cm−2 at −0.5 V with strong stability. Density functional theory calculations reveal that the introduction of Mo can induce the redistribution of electrons around Co atoms and further strengthen the adsorption of NO 2 −, which is the key to facilitating the catalytic performance. Furthermore, the assembled battery based on Mo-Co 3 O 4 /TM suggests its practical application value. [ABSTRACT FROM AUTHOR]

[Display omitted] Fe N C single atom catalysts (SACs) have attracted great interest due to their highly active FeN 4 sites. However, the pyrolysis treatment often leads to inevitable metal migration and aggregation, which reduces the catalytic activity. Moreover, due to the Fenton reaction caused by Fe N C in alkaline and acidic solutions, the presence of Fe and peroxide in electrodes may generate free radicals, resulting in serious degradation of the organic ionomer and the membrane. Herein, we report an original strategy of introducing Co single atoms into Fe N C catalysts, forming atomically dispersed bimetallic active sites (Fe Co NC) and improving the activity and stability of the catalyst. Benefiting from this strategy, Fe Co NC catalyst exhibits excellent oxygen reduction reaction (ORR) activity in alkaline media (E 1/2 = 0.88 V) and in acidic media (E 1/2 = 0.77 V). As the cathode of Zn-air battery (ZAB), Fe Co NC shows an excellent peak power density of 142.8 mW cm−2 and a specific capacity of 806.6 mAh/g Zn. This work provides a novel avenue to optimize and enhance the ORR performance of atomic dispersed Fe N C catalysts. [ABSTRACT FROM AUTHOR]

The temperature instability of piezoelectric properties in KNN-based ceramics has been a major bottleneck impeding them toward practical applications. Herein, we prepared multilayer composite ceramics using two kinds of textured thick films with different polymorphic phase transition temperatures. The composite ceramics simultaneously exhibited outstanding piezoelectric properties (d 33 = 400 ± 20 pC/N; S = 0.18 % at 40 kV/cm) and piezoelectric temperature stability (d 33 and S variation within 5 % and 2 %, respectively over the temperature range of room temperature to 180 °C). The synergistic contribution of slightly fluctuating ε r ·P r values, the robust phase and domain structures, and the complementary effect of piezoelectric fluctuation between the two composite layers led to the outstanding temperature stability of piezoelectric properties. Furthermore, the piezoelectric energy harvester produced using KNN-T 1 /T 2 composite ceramics exhibits a large power density of 5.4 mW/cm3. These results prove great potential of KNN-T 1 /T 2 ceramics in high temperature piezoelectric devices. [ABSTRACT FROM AUTHOR]

Iron‐nitrogen‐carbon (Fe‐N‐C) single‐atom catalysts are promising sustainable alternatives to the costly and scarce platinum (Pt) to catalyze the oxygen reduction reactions (ORR) at the cathode of proton exchange membrane fuel cells (PEMFCs). However, Fe‐N‐C cathodes for PEMFC are made thicker than Pt/C ones, in order to compensate for the lower intrinsic ORR activity and site density of Fe‐N‐C materials. The thick electrodes are bound with mass transport issues that limit their performance at high current densities, especially in H2/air PEMFCs. Practical Fe‐N‐C electrodes must combine high intrinsic ORR activity, high site density, and fast mass transport. Herein, it has achieved an improved combination of these properties with a Fe‐N‐C catalyst prepared via a two‐step synthesis approach, constructing first a porous zinc‐nitrogen‐carbon (Zn‐N‐C) substrate, followed by transmetallating Zn by Fe via chemical vapor deposition. A cathode comprising this Fe‐N‐C catalyst has exhibited a maximum power density of 0.53 W cm−2 in H2/air PEMFC at 80 °C. The improved power density is associated with the hierarchical porosity of the Zn‐N‐C substrate of this work, which is achieved by epitaxial growth of ZIF‐8 onto g‐C3N4, leading to a micro‐mesoporous substrate. [ABSTRACT FROM AUTHOR]

With the progressively widespread application of lithium‐ion batteries, their energy density and power density are being pursued to the extremely high. However, both cannot be reached simultaneously at present. Tortuosity depicts the relationship in ionic diffusion between bulk electrolyte and the electrolyte in a porous electrode, provides information about channels within electrodes, and correlates the current dilemma between energy density and power capability of the lithium‐ion batteries. It is crucial to upgrade the fast charging and discharging performance of LIBs electrodes without losing volumetric energy density and using tortuosity as a guide is able to achieve this goal fundamentally. Meanwhile, tortuosity can serve as an evaluation parameter for production quality assessment, but this demands a fast, accurate, and cost‐effective measuring method. After the definition and measurement of tortuosity are provided, this article analyzes the structural influencing factors of tortuosity which have impacts on ion transportation and subsequently on tortuosity to facilitate a more systematic and comprehensive picture. Through the discussion of contradictions and influencing factors, a more refined transmission line model (the refined TLM) is perceived as the very first step to drive both aforementioned goals toward success and is discussed in the perspective part. [ABSTRACT FROM AUTHOR]

Electrochemical supercapacitors are effectively involved and have potential attention in recent years due to the greatest advancements in energy storage system. In that, the electrode materials play a crucial role in achieving better electrochemical concert. In this work, three-dimensional NiO nanostructures were proposed as the high-capacity positive electrode for hybrid supercapacitors. In addition, the 3D-NiO electrode achieved a capacitance of 1100 F g−1 (605 C g−1) alone with 95.5% super stability retention. Similarly, a carbon-doped g-C3N4 nanosheet electrode involved as a negative electrode, which delivers a stability retention of 89.9%. Further, a hybrid supercapacitor device was made up of NiO as a positive, carbon-doped g-C3N4 as a negative material in an aqueous system, which shows the remarkable energy and power densities of 31.7 Wh kg−1 and 3625 W kg−1. The device delivers an admirable electrochemical performance that provides a huge active surface during the ion transportation process. These tolerable electrochemical results of this gathered hybrid supercapacitor device will be promoted as a various electronic tool in future generation. [ABSTRACT FROM AUTHOR]

Dielectric barrier discharge (DBD) plasma is used to prepare ternary heterostructured Ru–Co–B oxide catalyst with considerable RuO 2 /CoO/B 20 H 26 O interface and oxygen vacancy (Ov) for enhanced borohydride oxidation reaction. the Ru–Co–B catalyst displayed remarkable electrocatalytic activity and long-term stability Due to the difference in energy band structure at the interface where the charge distribution is not homogeneous, the heterogeneous structure will spontaneously generate a built-in electric field which prompts the interfacial charge transfer. The production of Ov increases its active site and promotes its catalytic activity. While it is used in membrane-less direct borohydride fuel cells (DBFCs), it showed a peak power density of 206 mW cm−2 at room temperature and a remarkable stability of 270 h at a constant current of 20 mA that is superior to commercial Pt/C. [Display omitted] • Heterogeneous catalysts with abundant oxygen vacancies were synthesized by plasma technology. • The use of ruthenium instead of platinum reduces the cost of the fuel cells. • The power density can reach 206 mW cm−2, the stability is greatly improved. • The preparation process does not need high temperature treatment, achieving green color, low energy consumption. [ABSTRACT FROM AUTHOR]

The deposition–dissolution mechanism with a two‐electron transfer reaction endows aqueous Zn–Mn batteries with a desirable theoretical energy density. However, due to the limited solubility of traditional manganese‐based materials and the competitive Mn shuttle behavior, the practical performance is unsatisfactory. Herein, by synergistically incorporating a novel Mn‐rich Mn4N cathode with a plasma functionalized carbon nanotubes film (PCNT) interlayer, an aqueous Zn–Mn battery with a high Mn‐utilization rate and high energy/power density is successfully developed. Specifically, the Mn4N cathode boasts high manganese content and dissolution activity, thereby offering a copious supply of Mn2+ ions for the battery system. The PCNT interlayer, with abundant micropore structures and functional groups, not only restrains the Mn2+ shuttle by entrapping the dissolved Mn2+ but also offers copious reaction sites, ensuring concentrating Mn2+ on the cathodic side and maximizing their contribution to the electrochemical reaction. Consequently, Mn4N‐PCNT exhibits a low polarization voltage and superior Mn‐utilization rate (64.8%). Without the MnSO4 additive, Mn4N‐PCNT achieves an ultra‐high energy density of 821.9 W h kg−1 and remarkable long‐term cycling stability (90% capacity retention over 9000 cycles). The delightful results demonstrate the practical application potential of Mn4N‐PCNT and open up new avenues for the rational design of advanced Zn–Mn batteries. [ABSTRACT FROM AUTHOR]

This work inspects the utilization of all-polymer solar cells (APSCs) in indoor applications under LED illumination, with a focus on boosting efficiency through simulation-based design. The study employs a SCAPS TCAD device simulator to investigate the performance of APSCs under white LED illumination at 1000 lux, with a power density of 0.305 mW/cm2. Initially, the simulator is validated against experimental results obtained from a fabricated cell utilizing CD1:PBN-21 as an absorber blend and PEDOT:PSS as a hole transportation layer (HTL), where the initial measured efficiency is 16.75%. The simulation study includes an examination of both inverted and conventional cell structures. In the conventional structure, where no electron transportation layer (ETL) is present, various materials are evaluated for their suitability as the HTL. NiO emerges as the most promising HTL material, demonstrating the potential to achieve an efficiency exceeding 27%. Conversely, in the inverted configuration without an HTL, the study explores different ETL materials to engineer the band alignment at the interface. Among the materials investigated, ZnS emerges as the optimal choice, recording an efficiency of approximately 33%. In order to reveal the efficiency limitations of these devices, the interface and bulk defects are concurrently investigated. The findings of this study underscore the significance of careful material selection and structural design in optimizing the performance of APSCs for indoor applications. [ABSTRACT FROM AUTHOR]

Measuring postural control in an upright standing position is the standard method. However, this diagnostic method has floor or ceiling effects and its implementation is only possible to a limited extent. Assessing postural control directly on the trunk in a sitting position and consideration of the results in the spectrum in conjunction with an AI-supported evaluation could represent an alternative diagnostic method quantifying neuromuscular control. In a prospective cross-sectional study, 188 subjects aged between 18 and 60 years were recruited and divided into two groups: "LowBackPain" vs. "Healthy". Subsequently, measurements of postural control in a seated position were carried out for 60 s using a modified balance board. A spectrum per trail was calculated using the measured CoP tracks in the range from 0.01 to 10 Hz. Various algorithms for data classification and prediction of these classes were tested for the parameter combination with the highest proven static influence on the parameter pain. The best results were found in a frequency spectrum of 0.001 Hz and greater than 1 Hz. After transforming the track from the time domain to the image domain for representation as power density, the influence of pain was highly significant (effect size 0.9). The link between pain and gender (p = 0.015) and pain and height (p = 0.012) also demonstrated significant results. The assessment of postural control in a seated position allows differentiation between "LowBackPain" and "Healthy" subjects. Using the AI algorithm of neural networks, the data set can be correctly differentiated into "LowBackPain" and "Healthy" with a probability of 81%. [ABSTRACT FROM AUTHOR]

Photosynthetic microbial fuel cells (pMFCs) are hybrid systems that enable simultaneous wastewater treatment under anaerobic conditions and the generation of electricity by utilizing the potential difference in the anaerobic anode chamber and the oxygenated cathode chamber. Dairy wastewater with a concentration of 2000 mg COD/L was treated in the anode of a batch pMFC. In the cathode chamber, Chlorella vulgaris or Arthrospira platensis was cultivated in synthetic medium, and next in diluted effluent from the anode chamber. The highest power density of 91 mW/m2 was generated by the pMFC with the cultivation of Arthrospira platensis. Higher values of dissolved oxygen remained during the dark phase in the cathodic medium with Arthrospira platensis cultivation than with Chlorella vulgaris. This depletion of oxygen significantly decreased voltage generation, which during the light phase increased again to the maximum values. The COD removal achieved in the anodic chamber was 87%. The efficiency of nitrogen removal in the cathode chamber during the cultivation of Arthrospira platensis and Chlorella vulgaris was about 78% and 69%, respectively. The efficiency of phosphorus removal in the cathode chamber with the cultivation of Arthrospira plantensis and Chlorella vulgaris was 58% and 43%, respectively. This study has shown that the introduction of Arthrospira platensis into the cathode chamber is more effective than that of Chlorella vulgaris. [ABSTRACT FROM AUTHOR]

Mixed-oxide transition-metal aerogels (AGLs), particularly manganese-based AGLs, have attracted considerable interest over the past decade owing to their extraordinary properties, including high porosity, good surface area, and ultralow density. To develop easy and lightweight materials for the ever-increasing energy storage demands of the near future, we designed a novel Mn-based electrode material to meet these rising requirements. MnO/Mn2O3 AGLs were synthesized using a novel borohydride hydrolysis method and then annealed at 200, 400, and 550 °C. The as-synthesized AGLs yielded flower-like network structures, but their porosity increased with increasing temperatures, to a high temperature of 400 °C. This increased porosity and network structure facilitate a high capacitance. A supercapacitor (SC) constructed with the three-electrode material yielded 230 F/g for the MnAGL@400 sample, followed by yields from the MnAGL@200 and MnAGL@550 electrodes. Furthermore, the device constructed with MnAGL@400 exhibited an energy density of 9.8 Wh/kg and a power density of ~16,500 W/kg at a current density of 20 A/g. The real-time applicability of the AGL was demonstrated by engineering a two-electrode device employing MnAGL@400 as the positive electrode, which exhibited 97% capacity retention and 109% Coulombic efficiency over 20,000 cycles. [ABSTRACT FROM AUTHOR]

In this study, a pulsed laser operating at a wavelength of 1064 nm and with a pulse width of 100 ns was utilized for the removal of paint from the surface of a 2024 aluminum alloy. The experimental investigation was conducted to analyze the influence of laser parameters on the efficacy of paint layer removal from the aircraft skin's surface and the subsequent evolution in the microstructure of the laser-treated aluminum alloy substrate. The mechanism underlying laser cleaning was explored through simulation. The findings revealed that power density and scanning speed significantly affected the quality of cleaning. Notably, there were discernible damage thresholds and optimal cleaning parameters in repetitive frequency, with a power density of 178.25 MW/cm2, scanning speed of 500 mm/s, and repetitive frequency of 40 kHz identified as the primary optimal settings for achieving the desired cleaning effect. Thermal ablation and thermal vibration were identified as the principal mechanisms of cleaning. Moreover, laser processing induced surface dislocations and concentrated stress, accompanied by grain refinement, on the aluminum substrate. [ABSTRACT FROM AUTHOR]

High-power pulse magnetron sputtering is a new type of magnetron sputtering technology that has advantages such as high peak power density and a high ionization rate compared to DC magnetron sputtering. In this paper, we report the effects of different pulse widths on the current waveform and plasma spectrum of target material sputtering, as well as the structure and properties of Cu films prepared under the same sputtering voltage and duty cycle. Extending the pulse width can make the sputtering enter the self-sputtering (SS) stage and improve the ion quantity of sputtered particles. The Cu film prepared by HiPIMS with long pulse width has higher bond strength and lower electrical resistivity compared to the Cu film prepared by short pulse width. In terms of microstructure, the Cu film prepared by HiPIMS with the long pulse width has a larger grain size and lower micro-surface roughness. When the pulse width is bigger than 200 μs, the microstructure of the Cu film changes from granular to branched. This transformation reduces the interface on the Cu film, further reducing the resistivity of the Cu film. Compared to short pulses, long pulse width HiPIMS can obtain higher quality Cu films. This result provides a new process approach for preparing high-quality Cu films using HiPIMS technology. [ABSTRACT FROM AUTHOR]

[Display omitted] Wood-conducting polymer materials have been widely used as supercapacitor electrode; however, it remains challenging to achieve a simple method to improve the homogeneity of the conductive material on wood and to reach high mass loading. Herein, a novel "pore-making, active substance-filling, densification (dissolution, in-situ polymerization of polyaniline (PANI), self-shrinking)" strategy is proposed for the preparation of wood electrodes with a high mass loading (41.4 wt%) and homogeneity. Ingeniously, ZnCl 2 as a dissolving agent and pore-making agent to treat delignified wood can generate more pores on the wood, which is more conducive to the penetration of aniline small molecules, besides, the dissolved fine fibers can be entangled with more PANI, which can improve the loading and homogeneity of PANI. After drying treatment, there will be shrinkage again, playing a certain physical densification effect on the large lumen. The optical electrode was RWP2 showing high electrochemical performance (2328.9 mF/cm2, 1 mA/cm2), and stability (5000 cycles, 89.3 %). Moving forward, the RWP2//RWP2 SSC showed an excellent energy density of 164.24 μwh/cm2 at a power density of 250 μw/cm2. Remarkably, the simple and versatile strategy of designing wood-based materials with high mass loading provides new research ideas for realizing multifunctional applications. [ABSTRACT FROM AUTHOR]

Nickel copper cobalt oxide (NiCuCoO) ternary metal oxide nanoparticles were synthesized by employing the hydrothermal method. NiCuCoO electrode demonstrates a specified capacity of 596 C g−1 at 1 A g−1, high capacitance retaining of 99% even if 1000 sequences at the density of current 10 A g−1, and significant extended cyclic strength over 1000 sequences. The gathered asymmetric supercapacitor (ASC) tool via NiCuCoO as the cathode and activated carbon as anode materials achieve a specified capacity of 168 C g−1 at a current density of 1 Ag−1, an excellent capacity retaining of 95% even later than 5000 sequences at a density of current 10 A g−1. The fabricated device exhibits a high density of energy and power is 96 Wh kg−1 and 841 W kg−1. The prepared material confirms an excellent capacitance routine, so this work represents for a next-generation energy storage device. [ABSTRACT FROM AUTHOR]

Carbon‐based metal‐free electrocatalysts have been recognized as inexpensive alternatives to afford excellent activity in oxygen reduction/evolution reactions (ORR/OER). Nevertheless, precisely identifying the local active sites and tailoring the corresponding electronic properties to enhance the reaction kinetics remain challenging. Herein, a facile strategy to create a metal‐free electrocatalyst comprised of a mesoporous nitrogen‐doped carbon matrix with phosphorus incorporation (NPC) is described. The as‐prepared NPC‐950 electrocatalyst demonstrates superior ORR activity under alkaline and acidic conditions with half‐wave potentials of 0.88 and 0.72 V, respectively, comparable to commercial Pt/C (0.85 and 0.76 V) and overwhelmingly superior to other N‐doped carbon catalyst materials. In addition, a remarkable promotion of OER activity under alkaline conditions is observed. Notably, a zinc–air battery equipped with this NCP‐950 electrocatalyst exhibits exceptional performance in peak power density, specific capacity, and long‐term operation durability. Theoretical calculations uncover that the incorporation of phosphorus in NC material results in effective charge density redistribution, thus modulating the electronic properties of active sites to achieve optimum adsorption and desorption of ORR intermediates. The work provides a deep understanding of active sites in heteroatom‐doped carbon materials and highlights the importance of the electronic properties modulation in oxygen bifunctional electrocatalytic activity. [ABSTRACT FROM AUTHOR]

The objective of this study is to perform an analysis to determine the most suitable type of wind turbine that can be installed at a specific location for electricity generation, using annual measurements of wind characteristics and meteorological parameters. Wind potential analysis has shown that the analyzed location is suitable for the development of a wind farm. The analysis was carried out for six different types of wind turbines, with a power ranging from 1.5 to 3.0 MW and a hub height set at 80 m. Wind power potential was assessed using the Weibull analysis. The values of the scale coefficient c were determined, and a large monthly variation was observed, with values ranging from 1.92 to 8.36 m/s and an annual value of 4.95 m/s. Monthly values for the shape coefficient k varied between 0.86 and 1.53, with an annual value of 1.07. Additionally, the capacity factor of the turbines was determined, ranging from 17.75 to 22.22%. The Vestas turbine, with a nominal power of 2 MW and a capacity factor of 22.22%, proved to be the most efficient wind turbine for the specific conditions of the location. The quantity of greenhouse gas emissions that will be reduced if this type of turbine is implemented was also calculated, considering the average CO2 emission intensity factor (kg CO2/kWh) of the national electricity system. [ABSTRACT FROM AUTHOR]

The fatty K+ ion calls for suitable host materials to meet the requirement for high safety and long‐term stability of potassium‐ion batteries (PIBs) to rival lithium‐ion batteries, thus anode materials possessing high capacity, high stability, and well‐defined plateaus involving favorable working voltage (≈0.5 V) have always been desired. Here, a 3D BiFeO3 with micro‐flower structure (BFO‐MF) constructed by nanosheets is proposed as an anode for PIBs. Density functional theory calculations evidence that the intrinsically favorable affinity and diffusion for K+ ion render fast electrochemical kinetics and attenuated voltage‐hysteresis, and electrochemical measurements indicate that the stable 3D structure of BFO‐MF enables to achieve impressive performances including a high capacity of 606 mAh g−1, flat plateaus at ≈0.5 V, stable performances for 5000 cycles at 500 mA g−1, and 500 cycles at 100 mA g−1 upon −20 °C. In situ and ex situ characterizations definitely elucidate the conversion and alloy/dealloy mechanism. The satisfying features of BFO‐MF anode ensure full‐cells to achieve excellent cyclic performances, and a high energy efficiency retention rate of ≈98.2% for the cathode, with energy density/power density output up to 177.1 Wh kg−1/2152.8 W kg−1, respectively. This work can provide new insights for developing advanced anodes for PIBs. [ABSTRACT FROM AUTHOR]

As a benchmark triple‐conducting cathode, BaCo0.4Fe0.4Zr0.1Y0.1O3−δ (BCFZY) has been widely investigated for protonic ceramic fuel cells (PCFC) in recent years. However, the reported electrochemical performance of BCFZY cathode differs, which is determined in this work to originate from the thermal expansion mismatch between BCFZY and electrolyte. Accordingly, two strategies for enhanced thermo‐mechanical compatibility are examined: impregnation and thermal expansion offset. In contrast to the impregnation of BCFZY nanoparticles on electrolyte backbones that only helps improve electrochemical performance, negative thermal expansion oxide Sm0.85Cu0.15MnO3−δ (SCM)‐offset BCFZY exhibits superior durability and activity simultaneously. Specifically, the polarization resistance decay rate of the SCM‐offset BCFZY is only ~0.2%/100 h, compared with ~18.75%/100 h for "impregnated BCFZY." Moreover, pure SCM generates moderate cathodic performance (area‐specific resistance = 0.11 Ω cm2, 700 °C), X‐ray diffraction and transmission electron microscopy reveal an in‐situ formed intergranular Ba2Cu3SmO7−δ phase at the boundaries of BCFZY and SCM. Thus, SCM can serve as a "three‐effect" additive, i) offset thermo‐expansion, ii) strengthen electrode structure and adhesion, and iii) provide acceptable oxygen‐reduction‐reaction activity, being favorable for superior performance. A PCFC using a SCM‐offset BCFZY cathode achieves the highest power density (1455 mW cm−2) yet recorded for PCFCs with BCFZY‐based cathodes. [ABSTRACT FROM AUTHOR]

A comprehensive investigation into the interaction between a continuous wave (CW) laser and lightweight quartz fiber reinforced phenolic (LQFRP) composite would provide valuable insights into the characteristics and performance of ablation. To simulate the CW laser ablation of LQFRP composite, a 2D symmetrical element model was developed, incorporating the heat conduction equation, resin pyrolysis mechanism, and deformed geometry module. This model was the first to examine the internal pyrolysis degree and gas flow field of LQFRP composite under CW laser irradiation, and its predictions were in reasonable agreement with experimental measurements. Additionally, the model was used to simulate CW laser ablation with varying spot sizes and power densities. The results revealed that during the laser ablation process, an internal high‐pressure zone formed on the side of the ablation hole. The volatilization of SiO2 was identified as the dominant dissipation mechanism for material removal. The width of the ablation hole was positively correlated with the laser spot size, while the depth of the ablation hole was positively correlated with the laser power density. Highlights: The model first studied the internal pyrolysis degree and flow field of LQFRP composite under laser irradiation.The volatilization of SiO2 was identified as the dominant dissipation mechanism for material removal.An internal high‐pressure zone formed on the side of the ablation hole during the laser ablation process.The width of the ablation hole was positively correlated with the laser spot size, while the depth of the ablation hole was positively correlated with the laser power density. [ABSTRACT FROM AUTHOR]