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Exploring new solid electrolytes (SEs) for lithium-ion conduction is significant for the development of rechargeable all-solid-state lithium batteries. Here, a lead-free organic-inorganic halide perovskite, MASr

Spin-polarized charge endows conventional lasers with not only new functionalities but also reduced lasing thresholds thanks to the lifting of spin degeneracy. II-VI and III-V semiconductors have been extensively investigated as spin laser gain mediums; however, the degree of polarization is limited by the light hole and heavy hole degeneracy. Herein, we evaluate the potential of CsPbBr

Metal halide perovskites are promising semiconductors for next-generation light-emitting diodes (LEDs) due to their high luminance, excellent color purity, and handily tunable band gap. However, it remains a great challenge to develop perovskite LEDs (PeLEDs) with pure red emission at the wavelength of 630 nm. Herein, we report a spectrally stable and efficient pure red PeLED by employing sequential ligand post-treated CsPbI3 quantum dots (QDs). The synthesized CsPbI3 QDs with a size of ∼5 nm are treated in sequential steps using the ligands of 1-hydroxy-3-phenylpropan-2-aminium iodide (HPAI) and tributylsulfonium iodide (TBSI), respectively. The CsPbI3 QD films exhibit improved optoelectronic properties, which enables the fabrication of a pure red PeLED with a peak external quantum efficiency (EQE) of 6.4% and a stable EL emission centered at the wavelength of 630 nm. Our reported sequential ligand post-treatment strategy opens a new route to improve the stability and efficiency of PeLEDs based on QDs.

Solution-processable all-inorganic CsPbI 3− x Br x perovskite holds great potential for pure red light-emitting diodes. However, the widely existing defects in this mixed halide perovskite markedly limit the efficiency and stability of present light-emitting diode devices. We here identify that intragrain Ruddlesden-Popper planar defects are primary forms of such defects in the CsPbI 3− x Br x thin film owing to the lattice strain caused by inhomogeneous halogen ion distribution. To eliminate these defects, we develop a stepwise metastable phase crystallization strategy to minimize the CsPbI 3− x Br x perovskite lattice strain, which brings planar defect–free CsPbI 3− x Br x thin film with improved radiative recombination, narrowed emission band, and enhanced spectral stability. Using these high-quality thin films, we fabricate spectrally stable pure red perovskite light-emitting diodes, showing 17.8% external quantum efficiency and 9000 candela meter −2 brightness with color coordinates required by Rec. 2020.

Chiral chromophores and their ordered assemblies are intriguing for yielding circularly polarized luminescence (CPL) and exploring intrinsic structure-light emission relationships. With the extensively studied chiral organic molecules and inorganic nanoparticle assemblies for the amplified CPL, the assemblies of copper halide hybrid clusters have attracted intensive attention due to their potential efficient CPL. Here, we report robust chiral phosphine-copper iodide hybrid clusters and their layered assemblies in crystalline states for amplified CPL. We reveal that the intermolecular interactions endow the clusters with the capability of assembling into chiral crystalline CPL materials, including hexagonal platelet-shaped microcrystals (glum ≈ 9.5 × 10-3) and highly oriented crystalline films (glum ≈ 5 × 10-3). Owing to the high crystalline feature of the thin film, we demonstrate an electroluminescent device with bright electroluminescence (1200 cd m-2).

Thermochromic phosphors are intriguing materials for realizing thermochromic behaviors of light-emitting diodes. Here a highly luminescent and stable thermochromic phosphor based on one-dimensional Cu

As one fundamental property of light, polarization has a huge impact in quantum optics and optoelectronics through light-matter interactions. However, the bright and near-unity polarized light emissions in the visible range by solid crystalline materials are scantly realized. Here, we report well-defined quasi two-dimensional (2D) hybrid crystals based on the linear alignment of Cu2I2-dimer/bidentate ligand hybrid clusters for achieving bright and near-unity linearly polarized light emissions. Using first-principle calculations, we demonstrate that the superaligned transition dipole moments are the key for the observed excellent polarized light emissions. To further enhance the photoluminescence (PL) polarization degree, we fabricate Cu2I2-dimer-based hybrid nanobelts, which display high PL quantum yield (up to 64%) and ultrahigh PL polarization degree (∼0.99). Our reported copper iodine cluster-based luminescent hybrid materials for bright and highly polarized light emissions will have great potential for future quantum optics applications.

Superior fast charging is a desirable capability of lithium-ion batteries, which can make electric vehicles a strong competition to traditional fuel vehicles. However, the slow transport of solvated lithium ions in liquid electrolytes is a limiting factor. Here, a Li

Extremely fast-charging lithium-ion batteries are highly desirable to shorten the recharging time for electric vehicles, but it is hampered by the poor rate capability of graphite anodes. Here, we present a previously unreported particle size and electrode porosity dual-gradient structure design in the graphite anode for achieving extremely fast-charging lithium ion battery under strict electrode conditions. We develop a polymer binder–free slurry route to construct this previously unreported type particle size-porosity dual-gradient structure in the practical graphite anode showing the extremely fast-charging capability with 60% of recharge in 10 min. On the basis of dual-gradient graphite anode, we demonstrate extremely fast-charging lithium ion battery realizing 60% recharge in 6 min and high volumetric energy density of 701 Wh liter −1 at the high charging rate of 6 C.

All-inorganic CsPbI

Objectives Subbranches of Y-chromosome haplogroup C2a-L1373 are founding paternal lineages in northern Asia and Native American populations. Our objective was to investigate C2a-L1373 differentiation in northern Asia and its implications for Native American origins. Materials and methods Sequences of rare subbranches (n = 43) and ancient individuals (n = 37) of C2a-L1373 (including P39 and MPB373), were used to construct phylogenetic trees with age estimation by BEAST software. Results C2a-L1373 expanded rapidly approximately 17.7,000-14.3,000 years ago (kya) after the last glacial maximum (LGM), generating numerous sublineages which became founding paternal lineages of modern northern Asian and Native American populations (C2a-P39 and C2a-MPB373). The divergence pattern supports possible initiation of differentiation in low latitude regions of northern Asia and northward diffusion after the LGM. There is a substantial gap between the divergence times of C2a-MPB373 (approximately 22.4 or 17.7 kya) and C2a-P39 (approximately 14.3 kya), indicating two possible migration waves. Discussion We discussed the decreasing time interval of "Beringian standstill" (2.5 ky or smaller) and its reduced significance. We also discussed the multiple possibilities for the peopling of the Americas: the "Long-term Beringian standstill model," the "Short-term Beringian standstill model," and the "Multiple waves of migration model." Our results support the argument from ancient DNA analyses that the direct ancestor group of Native Americans is an admixture of "Ancient Northern Siberians" and Paleolithic communities from the Amur region, which appeared during the post-LGM era, rather than ancient populations in greater Beringia, or an adjacent region, before the LGM.

All-inorganic cesium lead halide perovskite colloidal nanocrystals are attractive for next-generation light-emitting diodes because of their high color purity, but the nonradiative Auger recombination in perovskite nanocrystal film limits the efficiency and brightness of the fabricated devices. Here, we introduce a surface-engineering process to exchange the original long-chain oleic acid/oleylamine ligands by the cerium-tributylphosphine oxide hybrid ligands to suppress nonradiative Auger recombination in CsPbBr3 NC film for bright and low-efficiency roll-off light-emitting diodes. Using ultrafast transient absorption and time-resolved photoluminescence spectroscopy, we demonstrate that the hybrid ligand passivation can efficiently remove surface trap states to enhance radiative recombination and homogenize the exciton concentration to suppress nonradiative Auger recombination in the CsPbBr3 nanocrystal thin film. Consequently, we fabricate a light-emitting diode with efficient charge injection into the CsPbBr3 nanocrystal emitting layer, achieving a pronounced improvement of electroluminescence with an external quantum efficiency from 5.5% to 9.1%. More importantly, the efficiency roll-off characteristics of high-brightness light-emitting diodes is effectively mitigated. Our reported hybrid ligand passivation suppressed Auger recombination strategy shows a great potential for fabricating high-brightness cesium lead halide perovskite light-emitting diodes.

Background: Due to their long history, complex admixture processes and large population sizes, more research is required to explore the fine genetic structure of Han populations from different geographic locations of China.Aim: To characterise the paternal genetic structure of the Han Chinese in Henan province, which was once the central living region of the ancient Huaxia population, the precursors of the Han Chinese.Subjects and methods: We sequenced Y chromosomes of 60 males from Zhengzhou, Henan Province, and reconstructed a phylogenetic tree for these samples with age estimation.Results: We observed high diversity of paternal lineages in our collection. We found that the in situ Neolithic expansion of the "Major lineages" contributed to a large portion of the paternal gene pool of the Han population in Henan Province. We also detected a large number of "Minor lineages" that diverged in the Palaeolithic Age.Conclusion: We suggest that the high genetic diversity in the paternal gene pool of modern Han populations is mainly attributed to the reservation of a larger number of lineages that diverged in the Palaeolithic Age, while the recent expansion of limited lineages contributed to the majority of the gene pool of modern Han populations. We propose that such a structure is a basal characteristic for the genetic structure of modern Han populations.

Fabricating a robust interfacial layer on the lithium metal anode to isolate it from liquid electrolyte is vital to restrain the rapid degradation of a lithium metal battery. Here, we report that the solution-processed metal chloride perovskite thin film can be coated onto the lithium metal surface as a robust interfacial layer to shield the lithium metal from liquid electrolyte. Via phase analysis and density functional theory calculations, we demonstrate that the perovskite layer can allow fast lithium ion shuttle under a low energy barrier of 0.45 eV without the collapse of framework. Such perovskite modification can realize stable cycling of LiCoO2|Li cells with an areal capacity of 2.8 mAh cm−2 using thin lithium metal foil (50 μm) and limited electrolyte (20 μl mAh−1) for over 100 cycles at 0.5 C. The metal chloride perovskite protection strategy could open a promising avenue for advanced lithium metal batteries., Metal halide perovskite is well-known for the high absorption coefficient; however, its Li-ion transport property remains poorly explored. Here the authors coat an ion conducting metal chloride perovskite interfacial layer on the Li metal anode, enabling good battery performance.

Highly luminescent inks are desirable for various applications such as decorative coating, art painting, and anticounterfeiting, to name a few. However, present inks display low photoluminescent efficiency requiring a strong excitation light to make them glow. Here, we report a highly luminescent ink based on the copper-iodide/1-Propyl-1,4-diazabicyclo[2.2.2]octan-1-ium (Cu4I6(pr-ted)2) hybrid cluster with a quantum efficiency exceeding 98%. Under the interaction between the Cu4I6(pr-ted)2 hybrid cluster and polyvinylpyrrolidone (PVP), the highly luminescent Cu4I6(pr-ted)2/PVP ink can be facilely prepared via the one-pot solution synthesis. The obtained ink exhibits strong green light emission that originates from the efficient phosphorescence of Cu4I6(pr-ted)2 nanocrystals. Attractively, the ink displays high conversion efficiency for the ultraviolet light to bright green light emission due to its wide Stokes shift, implying great potential for anticounterfeiting and luminescent solar concentrator coating.

All-inorganic lead halide perovskite nanocrystals (NCs) are potential candidates for fabricating high-performance light-emitting diodes (LEDs) owing to their precisely tunable bandgaps, high photoluminescence (PL) efficiency, and excellent color purities. However, the performance of pure red (630-640 nm) all-inorganic perovskite LEDs is still limited by the halide segregation-induced instability of the electroluminescence (EL) of mixed halide CsPbI3-xBrx NCs. Herein, we report an effective approach to improving the EL stability of pure red all-inorganic CsPbI3-xBrx NC-based LEDs via the passivation of potassium bromide on NCs. By adding potassium oleate to the reaction system, we obtained potassium bromide surface-passivated (KBr-passivated) CsPbI3-xBrx NCs with pure red PL emission and a photoluminescence quantum yield (PLQY) exceeding 90%. We determine that most potassium ions present on the surface of NCs bind with bromide ions and thus demonstrate that potassium bromide surface passivation of NCs can both improve the PL stability and inhibit the halide segregation of NCs. Using KBr-passivated CsPbI3-xBrx NCs as an emitting layer, we fabricated stable and pure red perovskite LEDs with emission at 637 nm, showing a maximum brightness of 2671 cd m-2, maximum external quantum efficiency of 3.55%, and good EL stability. The proposed KBr-passivated NC strategy will open a new avenue for fabricating efficient, stable, and tunable pure color perovskite NC LEDs.

Solid electrolytes (SEs) with superionic conductivity and interfacial stability are highly desirable for stable all-solid-state Li-metal batteries (ASSLMBs). Here, we employ neural network potential to simulate materials composed of Li, Zr/Hf, and Cl using stochastic surface walking method and identify two potential unique layered halide SEs, named Li

High-voltage spinel cobalt-free LiNi

Hierarchically structured chiral luminescent materials hold promise for achieving efficient circularly polarized luminescence. However, a feasible chemical route to fabricate hierarchically structured chiral luminescent polycrystals is still elusive because of their complex structures and complicated formation process. We here report a biomimetic non-classical crystallization (BNCC) strategy for preparing efficient hierarchically structured chiral luminescent polycrystals using well-designed highly luminescent homochiral copper(I)-iodide hybrid clusters as basic units for biomimetic crystallization. By monitoring the crystallization process, we unravel the BNCC mechanism, which involves crystal nucleation, nanoparticles aggregation, oriented attachment, and mesoscopic transformation processes. We finally obtain the circularly polarized phosphors with both high luminescent efficiency (32%) and high luminescent dissymmetry factor (1.5 × 10-2), achieving the first demonstration of a circularly polarized phosphor converted light emitting diode with a polarization degree of 1.84% at room temperature. Our designed BNCC strategy provides a simple, reliable and large-scale synthetic route for preparing bright circularly polarized phosphors.

The application of prestresses is a valuable strategy for enhancing the overall mechanical performances of structural materials. Residual stresses, acting as prestresses, exist naturally in biological structural materials, such as the nacre with the 3D "brick-and-mortar" arrangement. Although regulation of the tablets sliding has recently been demonstrated to be vital to improve toughness in synthetic nacre-like structures, the effects of prestresses on the tablets-sliding mechanism in these nacre-like structures remain unclear. Here, by a combination of simulation, additive manufacturing, and drop tower testing the authors reveal that, at a critical prestress, synergistic effects between the prestress-enhanced tablets sliding and prestress-weakened structural integrality result in optimized impact resistance of nacre-like structures. Furthermore, the prestressing strategy is easily implemented to a designed nacre-inspired separator to enhance the impact resistance of lithium batteries. The findings demonstrate that the prestressing strategy combined with bioinspired architectures can be exploited for enhancing the impact resistance of engineering structural materials and energy storage devices.

Lead halide perovskite nanocrystals (PNCs) are emerging as promising light emitters to be actively explored for high color purity and efficient light-emitting diodes. However, the most reported lead halide perovskite nanocrystal light-emitting diodes (PNCLEDs) encountered issues of emission line width broadening and operation voltage elevating caused by the quantum confinement effect. Here, we report a new type of PNCLED using large-size CsPbBr3 PNCs overly exceeding the Bohr exciton diameter, achieving ultranarrow emission line width and rapid brightness rise around the turn-on voltage. We adopt calcium-tributylphosphine oxide hybrid ligand passivation to produce highly dispersed large-size colloidal CsPbBr3 PNCs with a weak size confinement effect and also high photoluminescence quantum yield (∼85%). Utilizing these large-size PNCs as emitters, we manifest that the detrimental effects caused by the quantum confinement effect can be avoided in the device, thereby realizing the highest color purity in green PNCLED, with a narrow full width at half-maximum of 16.4 nm and a high corrected maximum external quantum efficiency of 17.85%. Moreover, the operation half-life time of the large-size PNCLED is 5-fold of that based on smaller-size PNCs. Our work provides a new avenue for improving the performance of PNCLEDs based on unconventional large-size effects.

Metal halide perovskites are promising semiconductors for next-generation light-emitting diodes (LEDs) due to their high luminance, excellent color purity, and handily tunable band gap. However, it remains a great challenge to develop perovskite LEDs (PeLEDs) with pure red emission at the wavelength of 630 nm. Herein, we report a spectrally stable and efficient pure red PeLED by employing sequential ligand post-treated CsPbI

Electrolyte engineering via fluorinated additives is promising to improve cycling stability and safety of high-energy Li-metal batteries. Here, an electrolyte is reported in a porous lithium fluoride (LiF) strategy to enable efficient carbonate electrolyte engineering for stable and safe Li-metal batteries. Unlike traditionally engineered electrolytes, the prepared electrolyte in the porous LiF nanobox exhibits nonflammability and high electrochemical performance owing to strong interactions between the electrolyte solvent molecules and numerous exposed active LiF (111) crystal planes. Via cryogenic transmission electron microscopy and X-ray photoelectron spectroscopy depth analysis, it is revealed that the electrolyte in active porous LiF nanobox involves the formation of a high-fluorine-content (>30%) solid electrolyte interphase layer, which enables very stable Li-metal anode cycling over one thousand cycles under high current density (4 mA cm-2 ). More importantly, employing the porous LiF nanobox engineered electrolyte, a Li || LiNi0.8 Co0.1 Mn0.1 O2 pouch cell is achieved with a specific energy of 380 Wh kg-1 for stable cycling over 80 cycles, representing the excellent performance of the Li-metal pouch cell using practical carbonate electrolyte. This study provides a new electrolyte engineering strategy for stable and safe Li-metal batteries.

The ion energy distribution and average energy of Ar/O2 mixed gas discharge have been studied using quadrupole mass spectrometer. The results show that the potential increases in the sheath, the ions obtain higher energy through the sheath, high energy peak moves to high energy area and the energy width increases as low-frequency power increases, which is consistent with the theoretical model calculation results. When pressure rises, collisions of Ar+ ions are more frequent in the process of crossing the sheath, the bimodal structure becomes vaguely, and under the same condition the number of low energy ions increases gradually.

Summary Biomimetic bulk structural materials have been paid increasing attention for their huge application prospects. Integrating close-to-ideal, ultrathin, and flexible nanostructured units into high-performance nacreous bulk nanocomposites is worth considering yet remains challenging due to the elusive micro- and nano-interface connections. Here, by introducing a multiscale soft-rigid polymer dual-network interfacial design strategy that enables us to appropriately reinforce the nanoscale building blocks or their bridging, we can construct a type of nacreous bulk nanocomposites with tunable mechanical properties in the mild, eco-friendly, and highly efficient bottom-up assembly process. The resultant nanocomposites can achieve continuously reinforced mechanical transformation without experiencing environmentally threatening interfacial manipulation processes. This interfacial design strategy, supported by sufficient experiments and simulations, endows the assembled nacreous nanocomposite with superior mechanical enhancement and improved stability under high humidity and temperature conditions. Combined with the scalable assembly technique, it will pave the way for the design of high-performance biomimetic bulk nanocomposites for structural applications.

Separator, as one of the key components to isolate the cathode and anode in the cell, heavily influences the safety, life-span and energy density of lithium ion batteries (LIBs). Currently, most widely used separators in LIBs are polyethylene (PE) or polypropylene (PP) based porous membranes due to their good chemical/electrochemical stabilities and high ionic conductivities. However, the raw materials for these polyolefin-based separators are produced by a petrochemical process, which is not eco-efficient, environmentally friendly, and sustainable. In order to meet the requirements of sustainable development, using biopolymer fibers to fabricate separators for LIBs has attracted intensive attention owing to their excellent thermal stability, low cost, biodegradable and renewable benefits. Here, we present the recent progress of biopolymer fiber based membranes applied as separators in LIBs. In this review, we begin with a brief introduction of LIB separators with the basic requirements for the membranes to be used as separators. Then, we highlight several typical biopolymer fiber based membranes recently reported for the separators of LIBs. In this section, the main focus is put on the integration of biopolymer microfibril based membranes, biopolymer microfibril based composite membranes, biopolymer nanofiber based membranes and biopolymer nanofiber based composite membranes. Finally, we provide the perspectives on several issues that need further exploration in this active research field in the future.

Lithium metal based anode with hierarchical structure to enable high rate capability, volume change accommodation, and dendritic suppression is highly desirable for all-solid-state lithium metal battery. However, the fabrication of hierarchical lithium metal based anode is challenging due to the volatility of lithium. Here, we report that natural diatomite can act as an excellent template for constructing hierarchical silicon-lithium based hybrid anode for high performance all-solid-state lithium metal battery. This hybrid anode exhibits stable lithium stripping/plating performance over 1000 h with average overpotential lower than 100 mV without any short circuit. Moreover, all-solid-state full cell using this lithium metal composite anode to couple with lithium iron phosphate cathode shows excellent cycling stability (0.04% capacity decay rate for 500 cycles at 0.5C) and high rate capability (65 mAh g−1 at 5C). The present natural diatomite derived hybrid anode could further promote the fabrication of high performance all-solid-state lithium batteries from sustainable natural resources., Lithium metal is the anode of choice for the next-generation high energy density batteries. To address the key technological challenges, the authors report a hybrid Li anode design with hierarchical pores structure derived from natural diatomite and improved electrochemical performance in all-solid-state lithium batteries.

Cubic phase CsPbI3 quantum dots (α-CsPbI3 QDs) as a newly emerging type of semiconducting QDs hold tremendous promise for fundamental research and optoelectronic device applications. However, stable and sub-5 nm-sized α-CsPbI3 QDs have rarely been demonstrated so far due to their highly labile ionic structure and low phase stability. Here, we report a novel strontium-substitution along with iodide passivation strategy to stabilize the cubic phase of CsPbI3, achieving the facile synthesis of α-CsPbI3 QDs with a series of controllable sizes down to sub-5 nm. We demonstrate that the incorporation of strontium ions can significantly increase the formation energies of α-CsPbI3 QDs and hence reduce the structure distortion to stabilize the cubic phase at the few-nanometer size. The size ranging from 15 down to sub-5 nm of as-prepared stable α-CsPbI3 QDs allowed us to investigate their unique size-dependent optical properties. Strikingly, the few-nanometer-sized α-CsPbI3 QDs turned out to retain high photolumine...

Scaling up electrochemical water splitting is nowadays in high demand for hydrogen economy implementation. Tremendous efforts over the past decade have been focused on exploring alternative catalytic materials, including a variety of earth-abundant transition-metal-based catalysts, to replace traditional noble metals such as Pt, Ir, or Ru. Nevertheless, few efforts have been carried out for (1) scalable catalyst synthesis on current collectors and (2) practical device design toward large-scale H2 generation. Herein, we designed a modular alkaline water-splitting electrolyzer system with scaled-up metal foam electrodes covered by low-cost NiMo alloy and Ni3Fe oxide for efficient hydrogen evolution and oxygen evolution, respectively. An electrolyte circulation system facilitates the mass transport and thus can further boost the H2 generation particularly under large currents. As a result, the overall water-splitting performance of one-unit cell with a dimension of 10 × 10 cm2 under room temperature presents an early onset voltage of 1.54 V and delivered practical currents of 20 and 55 A (9.1 and 25.0 L/h H2 generation) under 2.2 and 2.9 V without iR compensations, respectively. This demonstration could stimulate new focuses in water splitting toward more practical applications.

Two-dimensional (2D) boron nitride nanosheets (BNNSs) were chemically exfoliated from bulk boron nitride and coated onto the surface of a poly(ethylene oxide) (PEO)-based electrolyte through a dry-pressing transfer process. The fabricated BNNSs coating formed a robust interfacial layer to improve the chemical and mechanical stability of the PEO-based electrolyte, leading to the enhanced performance of solid-state Li metal batteries.

Using highly dispersed metal fluoride nanoparticles to construct a uniform fluorinated alloy type interfacial layer on the surface of Li metal anodes is realized by an ex situ solution chemical modification method. The fluorinated alloy-type interfacial layer can effectively inhibit the growth of undesirable Li dendrites while enhancing the performance of Li metal anodes.