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Polysulfide shuttling and dendrite growth are two primary challenges that significantly limit the practical applications of lithium–sulfur batteries (LSBs). Herein, a three-in-one strategy for a separator based on a localized electrostatic field is demonstrated to simultaneously achieve shuttle inhibition of polysulfides, catalytic activation of the Li–S reaction, and dendrite-free plating of lithium ions. Specifically, an interlayer of polyacrylonitrile nanofiber (PNF) incorporating poled BaTiO3(PBTO) particles and coating with a layer of MoS2(PBTO@PNF-MoS2) is developed on the PP separator. Theoretical calculations and experimental work show that the electric field generated at the membrane facilitates the fast and uniform transport of Li+ions, thereby inhibiting dendrite growth. Additionally, the generated electric field promotes the MoS2catalytic activity toward the Li–S redox reactions, particularly by reducing the reaction barriers for both the solid–liquid and solid–solid conversions. As a result, symmetrical Li//PBTO@PNF/PP/PBTO@PNF//Li cells demonstrate remarkable stability over 1200 h, and LSBs with a PP/PBTO@PNF-MoS2composite separator maintain a specific capacity of 318.3 mA h g–1after 4000 cycles at 2C, with an ultralow capacity decay rate of 0.015%. In addition, the PBTO@PNF membrane also enhances the mechanical flexibility and thermal stability of the composite separator.

This review focuses on recent advances in the synthesis and application of high entropy alloy electrocatalysts, and current challenges and potential solutions are also discussed.

Instruments for gamma-ray astronomy at Very High Energies (E>100GeV) have traditionally derived their scientific results through proprietary data and software. Data standardisation has become a prominent issue in this field both as a requirement for the dissemination of data from the next generation of gamma-ray observatories and as an effective solution to realise public data legacies of current-generation instruments. Specifications for a standardised gamma-ray data format have been proposed as a community effort and have already been successfully adopted by several instruments. We present the first production of standardised data from the Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes. We converted 166hof observations from different sources and validated their analysis with the open-source software Gammapy. We consider six data sets representing different scientific and technical analysis cases and compare the results obtained analysing the standardised data with open-source software against those produced with the MAGIC proprietary data and software. Aiming at a systematic production of MAGIC data in this standardised format, we also present the implementation of a database-driven pipeline automatically performing the MAGIC data reduction from the calibrated down to the standardised data level. In all the cases selected for the validation, we obtain results compatible with the MAGIC proprietary software, both for the manual and for the automatic data productions. Part of the validation data set is also made publicly available, thus representing the first large public release of MAGIC data. This effort and this first data release represent a technical milestone toward the realisation of a public MAGIC data legacy.

The commercialization of lithium–sulfur batteries (LSBs) faces significant challenges due to persistent issues, such as the shuttle effect of lithium polysulfides (LiPSs) and the slow kinetics of cathodic reactions. To address these limitations, this study proposes a vacancy-engineered cobalt ditelluride catalyst (v-CoTe2) supported on nitrogen-doped carbon as a sulfur host at the cathode. Density functional theory calculations and experimental results indicate that the electron configuration modulation of v-CoTe2enhances the chemical affinity and catalytic activity toward LiPS. Specifically, v-CoTe2can strongly interact with PSs through multisite coordination, effectively facilitating the kinetics of the LiPS redox reaction. Furthermore, the introduction of Te vacancies generates a large number of spin-polarized electrons, further enhancing the reaction kinetics of LiPS. As a result, the v-CoTe2@S cathode demonstrates high initial capacity and excellent cyclic stability, maintaining 80.4% capacity after 500 cycles at a high current rate of 3 C. Even under a high sulfur load of 6.7 mg cm–2, a high areal capacity of 6.1 mA h cm–2is retained after 50 cycles. These findings highlight the significant potential of Te vacancies in CoTe2as a sulfur host material for LSBs.

Catalytic additives able to accelerate the lithium–sulfur redox reaction are a key component of sulfur cathodes in lithium–sulfur batteries (LSBs). Their design focuses on optimizing the charge distribution within the energy spectra, which involves refinement of the distribution and occupancy of the electronic density of states. Herein, beyond charge distribution, we explore the role of the electronic spin configuration on the polysulfide adsorption properties and catalytic activity of the additive. We showcase the importance of this electronic parameter by generating spin polarization through a defect engineering approach based on the introduction of Co vacancies on the surface of CoSe nanosheets. We show vacancies change the electron spin state distribution, increasing the number of unpaired electrons with aligned spins. This local electronic rearrangement enhances the polysulfide adsorption, reducing the activation energy of the Li–S redox reactions. As a result, more uniform nucleation and growth of Li2S and an accelerated liquid–solid conversion in LSB cathodes are obtained. These translate into LSB cathodes exhibiting capacities up to 1089 mA h g–1at 1 C with 0.017% average capacity loss after 1500 cycles, and up to 5.2 mA h cm–2, with 0.16% decay per cycle after 200 cycles in high sulfur loading cells.

Lithium metal batteries (LMBs), with high energy densities, are strong contenders for the next generation of energy storage systems. Nevertheless, the unregulated growth of lithium dendrites and the unstable solid electrolyte interphase (SEI) significantly hamper their cycling efficiency and raise serious safety concerns, rendering LMBs unfeasible for real-world implementation. Covalent organic frameworks (COFs) and their derivatives have emerged as multifunctional materials with significant potential for addressing the inherent problems of the anode electrode of the lithium metal. This potential stems from their abundant metal-affine functional groups, internal channels, and widely tunable architecture. The original COFs, their derivatives, and COF-based composites can effectively guide the uniform deposition of lithium ions by enhancing conductivity, transport efficiency, and mechanical strength, thereby mitigating the issue of lithium dendrite growth. This review provides a comprehensive analysis of COF-based and derived materials employed for mitigating the challenges posed by lithium dendrites in LMB. Additionally, we present prospects and recommendations for the design and engineering of materials and architectures that can render LMBs feasible for practical applications.

The development of advanced cathode materials able to promote the sluggish redox kinetics of polysulfides is crucial to bringing lithium–sulfur batteries to the market. Herein, two electrode materials: namely, Zr2PS2and Zr2PTe2, are identified through screening several hundred thousand compositions in the Inorganic Crystal Structure Database. First-principles calculations are performed on these two materials. These structures are similar to that of the classical MXenes. Concurrently, calculations show that Zr2PS2and Zr2PTe2possess high electrical conductivity, promote Li ion diffusion, and have excellent electrocatalytic activity for the Li–S reaction and particularly for the Li2S decomposition. Besides, the mechanisms behind the excellent predicted performance of Zr2PS2and Zr2PTe2are elucidated through electron localization function, charge density difference, and localized orbital locator. This work not only identifies two candidate sulfur cathode additives but may also serve as a reference for the identification of additional electrode materials in new generations of batteries, particularly in sulfur cathodes.

While lead sulfide shows notable thermoelectric properties, its production costs remain high, and its mechanical hardness is low, which constrains its commercial viability. Herein, we demonstrate a straightforward and cost-effective method to produce PbS nanocrystals at ambient temperature. By introducing controlled amounts of silver, we achieve p-type conductivity and fine-tune the energy band structure and lattice configuration. Computational results show that silver shifts the Fermi level into the valence band, facilitating band convergence and thereby enhancing the power factor. Besides, excess silver is present as silver sulfide, which effectively diminishes the interface barrier and enhances the Seebeck coefficient. Defects caused by doping, along with dislocations and interfaces, reduce thermal conductivity to 0.49 W m–1K–1at 690 K. Moreover, the alterations in crystal structure and chemical composition enhance the PbS mechanical properties. Overall, optimized materials show thermoelectric figures of merit approximately 10-fold higher than that of pristine PbS, alongside an average hardness of 1.08 GPa.

Recognition-encoded melamine oligomers (REMO) are synthetic polymers that feature an alternating 1,3,5-triazine-piperazine backbone and side-chains equipped with either a phenol or phosphine oxide recognition unit. An automated method for the solid-phase synthesis (SPS) of REMO of any specified sequence has been developed starting from dichlorotriazine monomer building blocks. Complementary homo-oligomers with either six phenols or six phosphine oxides were synthesized and shown to form a stable duplex in nonpolar solvents by NMR denaturation experiments. The duplex was covalently trapped by equipping the ends of the oligomers with an azide and an alkyne group and using a copper-catalyzed alkyne–azide cycloaddition (CuAAC) reaction. The SPS methodology was adapted to synthesize mixed sequence libraries by using a mixture of two different dichlorotriazine building blocks in each coupling cycle of an oligomer synthesis. The resulting libraries contain statistical mixtures of all possible sequences. The self-assembly properties of these libraries were screened by using the CuAAC reaction to trap any duplexes present. In mixed sequence libraries of 6-mers, the trapping experiments showed that only sequence-complementary oligomers formed duplexes at micromolar concentrations in dichloromethane. The automated synthesis approach developed here provides access to large libraries of mixed sequence synthetic polymers, and the covalent trapping experiment provides a convenient tool for screening functional properties of mixtures. The results suggest high-fidelity sequence-selective duplex formation in mixtures of 6-mer sequences of the REMO architecture.

Electrocatalytic hydrogenation (ECH) approaches under ambient temperature and pressure offer significant potential advantages over thermal hydrogenation processes but require highly active and efficient hydrogenation electrocatalysts. The performance of such hydrogenation electrocatalysts strongly depends not only on the active phase but also on the architecture and surface chemistry of the support material. Herein, Pd nanoparticles supported on a nickel metal–organic framework (MOF), Ni-MOF-74, are prepared, and their activity toward the ECH of benzaldehyde (BZH) in a 3 M acetate (pH 5.2) aqueous electrolyte is explored. An outstanding ECH rate up to 283 μmol cm–2h–1with a Faradaic efficiency (FE) of 76% is reached. Besides, higher FEs of up to 96% are achieved using a step-function voltage. Materials Studio and density functional theory calculations show these outstanding performances to be associated with the Ni-MOF support that promotes H-bond formation, facilitates water desorption, and induces favorable tilted BZH adsorption on the surface of the Pd nanoparticles. In this configuration, BZH is bonded to the Pd surface by the carbonyl group rather than through the aromatic ring, thus reducing the energy barriers of the elemental reaction steps and increasing the overall reaction efficiency.

• Modulation doping. • Thermoelectric. • Interphase charge transport. • Phonon-carrier scattering. The commercial viability of thermoelectric (TE) devices relies heavily on two factors: cost reduction and efficiency enhancement. In this study, we first produce p-type Cu 12 Sb 4 S 16– x (x = 0, 3, 4) using a low-temperature bottom-up approach and demonstrate Cu 12 Sb 4 S 13 to show the best TE performance among the three tested compositions. Subsequently, the TE energy conversion efficiency of Cu 12 Sb 4 S 13 is further enhanced by optimizing its electronic band structure through the incorporation of small amounts of tellurium. At an optimal Te content of 5 mol%, more than a twofold increase in the TE figure of merit (zT) is obtained. To gain insight into the mechanism of improvement on the transport properties of the material, we compare the interphase transport mechanism by incorporating nanodomains of different metals (Ag and Cu) into the Cu 12 Sb 4 S 13 matrix. The improved electrical conductivity obtained with Cu 12 Sb 4 S 13 -Te nanocomposites is attributed to a charge flooding of the Cu 12 Sb 4 S 13 surface. In contrast, excessive downward band-bending at the interphases of Ag/Cu metal-semiconductor drastically reduces the electrical conductivity. Besides, a weighted mobility (μ w) analysis shows a dominant thermal activation of carriers in Cu 12 Sb 4 S 13 -Te nanocomposites. In this material, a strong decrease in lattice thermal conductivity is also found, which is associated with a phonon-carrier scattering mechanism. Our work shows the importance of proper band-engineering in TE nanocomposites to decouple electrical and thermal transport to enhance TE performance, and the efficacy of μ w for electrical and thermal transport analysis. [ABSTRACT FROM AUTHOR]

We propose a novel transient partial differential equation (PDE) model for the development of highly sensitive microthermal expansion-based angular motion ( $\mu $ TEAM) sensors based on the study of time-dependent response. With the efficient prediction of thermal time constant ( $\tau ^{\ast} $ ) based on the PDE model, which is >2200 times faster than 3-D CFD simulation (32.67 s versus >20 h) and was validated by the experimental results, the parametric analysis has been conducted for design optimization. The $\mu $ TEAM sensors with three pairs of temperature detectors (TDs) were adopted for the systematic study of the PWM frequency ( ${f} _{\text {PWM}}$ ) effect on the sensor performance to identify the optimal ${f} _{\text {PWM}}$ ( ${f} _{\text {o}}$ ), which can optimize the sensitivity by >11%. Based on the time-dependent analysis of our PDE model, ${f} _{\text {o}}$ was verified to be dominated by the thermal response of the sensor. A generalized “Phase Diagram” regarding the normalized sensitivity ( $S^{\ast} $ ) was presented, for the first time, as a function of ${f} _{\text {PWM}}$ and the normalized heater-to-detector distance ( ${D} _{x}/{L} _{x}$ ). Accordingly, an optimal region, where $S^{\ast} \ge0.95$ , was identified to successfully develop an SF 6-based $\mu $ TEAM sensor with a high sensitivity of 1.5631 mV/°/s, which was >3.5 times as large as that of the N2-based sensor (0.4203 mV/°/s). In particular, the SF6-based sensor reveals an excellent normalized sensitivity of 0.0487 mV/°/s/mW compared to the reported thermal angular motion sensors (AMSs); thus, the comprehensive study based on the PDE model enables the significant improvement of sensor sensitivity and would be useful for system-level integration in the future.

Lithium–sulfur batteries are regarded as an advantageous option for meeting the growing demand for high-energy-density storage, but their commercialization relies on solving the current limitations of both sulfur cathodes and lithium metal anodes. In this scenario, the implementation of lithium sulfide (Li2S) cathodes compatible with alternative anode materials such as silicon has the potential to alleviate the safety concerns associated with lithium metal. In this direction, here, we report a sulfur cathode based on Li2S nanocrystals grown on a catalytic host consisting of CoFeP nanoparticles supported on tubular carbon nitride. Nanosized Li2S is incorporated into the host by a scalable liquid infiltration–evaporation method. Theoretical calculations and experimental results demonstrate that the CoFeP–CN composite can boost the polysulfide adsorption/conversion reaction kinetics and strongly reduce the initial overpotential activation barrier by stretching the Li–S bonds of Li2S. Besides, the ultrasmall size of the Li2S particles in the Li2S–CoFeP–CN composite cathode facilitates the initial activation. Overall, the Li2S–CoFeP–CN electrodes exhibit a low activation barrier of 2.56 V, a high initial capacity of 991 mA h gLi2S–1, and outstanding cyclability with a small fading rate of 0.029% per cycle over 800 cycles. Moreover, Si/Li2S full cells are assembled using the nanostructured Li2S–CoFeP–CN cathode and a prelithiated anode based on graphite-supported silicon nanowires. These Si/Li2S cells demonstrate high initial discharge capacities above 900 mA h gLi2S–1and good cyclability with a capacity fading rate of 0.28% per cycle over 150 cycles.

In this study, we report the easy and low-cost synthesis of calcium niobate (CaNb2O6) with the isomorphic structure of the Rynersonite mineral for CaTa2O6. The samples were prepared by the ball milling method at room temperature at a synthesis time of 0.5, 1, 2, 3, and 4 h. The structural analysis by XRD, Rietveld refinement, and vibrational Raman spectroscopy confirms all diffraction peaks and active mode characteristics of the pure phase of CaNb2O6for the 3-h and 4-h samples, with a crystallite size of 22.5 and 23.2 nm, respectively. The optical band gap obtained was 3.18(2) eV (3-h sample), lower than the optical band gap for niobium oxide, characteristic of materials with strong photon absorption in the UVA region of the spectrum. The surface analysis by scanning electron microscopy reveals the obtention of several agglomerates of irregular particles ranging in the submicro and micro scales. Therefore, the present approach successfully obtained calcium niobate with the formula CaNb2O6at a short synthesis time and room temperature.

Aqueous zinc-ion batteries (ZIBs) are promising candidates to power flexible integrated functional systems because they are safe and environmentally friendly. Among the numerous cathode materials proposed, Mn-based compounds, particularly MnO2, have attracted special attention because of their high energy density, nontoxicity, and low cost. However, the cathode materials reported so far are characterized by sluggish Zn2+storage kinetics and moderate stabilities. Herein, a ZIB cathode based on reduced graphene oxide (rGO)-coated MnSe nanoparticles (MnSe@rGO) is proposed. After MnSe was activated to α-MnO2, the ZIB exhibits a specific capacity of up to 290 mAh g–1. The mechanism underlying the improvement in the electrochemical performance of the MnSe@rGO based electrode is investigated using a series of electrochemical tests and first-principles calculations. Additionally, in situ Raman spectroscopy is used to track the phase transition of the MnSe@rGO cathodes during the initial activation, proving the structural evolution from the LO to MO6mode. Because of the high mechanical stability of MnSe@rGO, flexible miniaturized energy storage devices can be successfully printed using a high-precision electrohydrodynamic (EHD) jet printer and integrated with a touch-controlled light-emitting diode array system, demonstrating the application of flexible EHD jet-printed microbatteries.

The growth mechanism and synthetic controls for colloidal multinary metal chalcogenide nanocrystals (NCs) involving alkali metals and the pnictogen metals Sb and Bi are unknown. Sb and Bi are prone to form metallic nanocrystals that stay as impurities in the final product. Herein, we synthesize colloidal NaBi1–xSbxSe2–ySyNCs using amine–thiol–Se chemistry. We find that ternary NaBiSe2NCs initiate with Bi0nuclei and an amorphous intermediate nanoparticle formation that gradually transforms into NaBiSe2upon Se addition. Furthermore, we extend our methods to substitute Sb in place of Bi and S in place of Se. Our findings show the initial quasi-cubic morphology transforms into a spherical shape upon increased Sb substitution, and the S incorporation promotes elongation along the <111> direction. We further investigate the thermoelectric transport properties of the Sb-substituted material displaying very low thermal conductivity and n-type transport behavior. Notably, the NaBi0.75Sb0.25Se2material exhibits an ultralow thermal conductivity of 0.25 W·m–1·K–1at 596 K with an average thermal conductivity of 0.35 W·m–1·K–1between 358 and 596 K and a ZTmaxof 0.24.

There is a need for the development of lead-free thermoelectric materials for medium-/high-temperature applications. Here, we report a thiol-free tin telluride (SnTe) precursor that can be thermally decomposed to produce SnTe crystals with sizes ranging from tens to several hundreds of nanometers. We further engineer SnTe–Cu2SnTe3nanocomposites with a homogeneous phase distribution by decomposing the liquid SnTe precursor containing a dispersion of Cu1.5Te colloidal nanoparticles. The presence of Cu within the SnTe and the segregated semimetallic Cu2SnTe3phase effectively improves the electrical conductivity of SnTe while simultaneously reducing the lattice thermal conductivity without compromising the Seebeck coefficient. Overall, power factors up to 3.63 mW m–1K–2and thermoelectric figures of merit up to 1.04 are obtained at 823 K, which represent a 167% enhancement compared with pristine SnTe.