Ni3C/Ni3S2 Heterojunction Electrocatalyst for Efficient Methanol Oxidation via Dual Anion Co-modulation Strategy.

Enhancing active states on the catalyst surface by modulating the adsorption-desorption properties of reactant species is crucial to optimizing the electrocatalytic activity of transition metal-based nanostructured materials. In this work, an efficient optimization strategy is proposed by co-modulating the dual anions (C and S) in Ni3C/Ni3S2, the heterostructured electrocatalyst, which is prepared via a simple hot-injection method. The presence of Ni3C/Ni3S2 heterojunctions accelerates the charge carrier transfer and promotes the generation of active sites, enabling the heterostructured electrocatalyst to achieve current densities of 10/100 mA cm-2 at 1.37 V/1.53 V. The Faradaic efficiencies for formate production coupled with hydrogen evolution approach 100%, accompanied with a stability record of 350 h. Additionally, operando electrochemical impedance spectroscopy (EIS), in situ Raman spectroscopy, and density functional theory (DFT) calculations further demonstrate that the creation of Ni3C/Ni3S2 heterointerfaces originating from dual anions' (C and S) differentiation is effective in adjusting the d-band center of active Ni atoms, promoting the generation of active sites, as well as optimizing the adsorption and desorption of reaction intermediates. This dual anions co-modulation strategy to stable heterostructure provides a general route for constructing high-performance transition metal-based electrocatalysts.

Conductive Zeolite Supported Indium-Tin Alloy Nanoclusters for Selective and Scalable Formic Acid Electrosynthesis.

Upgrading excess CO2 toward the electrosynthesis of formic acid is of significant research and commercial interest. However, simultaneously achieving high selectivity and industrially relevant current densities of CO2-to-formate conversion remains a grand challenge for practical implementations. Here, an electrically conductive zeolite support is strategically designed by implanting Sn ions into the skeleton structure of a zeolite Y, which impregnates ultrasmall In0.2Sn0.8 alloy nanoclusters into the supercages of the tailored 12-ring framework. The prominent electronic and geometric interactions between In0.2Sn0.8 nanoalloy and zeolite support lead to the delocalization of electron density that enhances orbital hybridizations between In active site and *OCHO intermediate. Thus, the energy barrier for the rate-limiting *OCHO formation step is reduced, facilitating the electrocatalytic hydrogenation of CO2 to formic acid. Accordingly, the developed zeolite electrocatalyst achieves an industrial-level partial current density of 322 mA cm-2 and remarkable Faradaic efficiency of 98.2% for formate production and stably maintains Faradaic efficiency above 93% at an industrially relevant current density for over 102 h. This work opens up new opportunities of conductive zeolite-based electrocatalysts for industrial-level formic acid electrosynthesis from CO2 electrolysis and toward practically accessible electrocatalysis and energy conversion.

Molybdenum-Oxysulfide-Functionalized MgAl-Layered Double Hydroxides─A Sorbent for Selenium Oxoanions.

Effective removal of chemically toxic selenium oxoanions at high-capacity and trace levels from contaminated water remains a challenge in current scientific pursuits. Here, we report the functionalization of the MgAl layered double hydroxide with molybdenum-oxysulfide (MoO2S2) anion, referred to as LDH-MoO2S2, and its potential to sequester SeVIO42- and SeIVO32- from aqueous solution. LDH-MoO2S2 nanosheets were synthesized by an ion exchange method in solution. Synchrotron X-ray pair distribution function (PDF) and extended X-ray absorption fine structure (EXAFS) revealed an unexpected transformation of the MoO2S22- to Mo2O2S62- like species during the intercalation process. LDH-MoO2S2 is remarkably efficient in removing SeO42- and SeO32- ions from the ppm to trace level (≤10 ppb), with distribution constant (Kd) ranging from 104 to 105 mL/g. This material showed exceptionally high sorption capacities of 237 and 358 mg/g for SeO42- and SeO32-, respectively. Furthermore, LDH-MoO2S2 demonstrates substantial affinity and efficiency to remove SeO32-/SeO42- even in the presence of competitive ions from contaminated water. Hence, the removal of selenium (VI/IV) oxoanions collectively occurs through reductive precipitation and ion exchange mechanisms. This work provides significant insights into the chemical structure of the MoO2S2 anion into LDH and emphasizes its exceptional potential for high-capacity selenium removal and positioning it as a premier sorbent for selenium oxoanions.

Accelerated Discovery of (TiZrHf)x(NbTa)1- x High-Entropy Alloys With Superior Thermal Stability and a New Crystallization Mechanism.

Nanocrystalline (nc) metals are generally strong yet thermally unstable, rendering them difficult to process and unsuitable for use, particularly at elevated temperatures. Nc multicomponent and high-entropy alloys (HEAs) are found to offer enhanced thermal stability but only in a few empirically discovered systems out of a vast compositional space. In response, this work develops a combinatorial strategy to accelerate the discovery of nc-(TiZrHf)x(NbTa)1- x alloy library with distinct thermal stability, in terms of phases and grain sizes. Based on synchrotron X-ray diffraction and electron microscopy characterizations, a phase transition is observed from amorphous-crystalline nanocomposites to a body-centered cubic (bcc) phase upon annealing. With increased NbTa content (decreased x value), the system tends to achieve thermally stable dual bcc phases upon annealing; in contrast, alloys with increased TiZrHf content (x > 0.6) maintain a single-composition nanocomposite state, impeding crystallization and grain growth. This investigation not only broadens the understanding of thermal stability but also delves into the onset of crystallization in HEA systems.

Analysis of microscopy techniques to measure segregation in continuous-cast steel slabs.

The accurate characterisation of centreline segregation requires precise measurements of composition variations over large length scales (10 - 1 $^{-1}$ m ${\rm {m}}$ ) across the centreline of the cast product, while having high resolution, sufficient to quantify the significant composition variations between dendrites due to microsegregation at very small length scales (10 - 5 m $^{-5}{\rm {m}}$ ). This study investigates the potential of a novel microscopy technique, named Synchrotron Micro X-ray Flurorescence (SMXRF), to generate large-scale high-resolution segregation maps from a steel sample taken from a thin slab caster. Two methods, Point Analysis and Regression Analysis, are proposed for SMXRF data calibration. By comparing with the traditional Laser-Induced Breakdown Spectroscopy (LIBS), and Electron Probe Micro Analyser (EPMA) techniques, we show that SMXRF is successful in quantitative characterisation of centreline segregation. Over large areas (e.g. 12 × $\times$ 16 mm 2 ${\rm {mm}}^2$ ) and at high resolution (10-50 µ m $\mu\text{m}$ pixel size) various techniques yield comparable outcomes in terms of composition maps and solute profiles. The findings also highlight the importance of both high spatial resolution and large field of view to have a quantitative, accurate, and efficient measurement tool to investigate segregation phenomena.

Mo3S13 Chalcogel: A High-Capacity Electrode for Conversion-Based Li-Ion Batteries.

Despite large theoretical energy densities, metal-sulfide electrodes for energy storage systems face several limitations that impact the practical realization. Here, we present the solution-processable, room temperature (RT) synthesis, local structures, and application of a sulfur-rich Mo3S13 chalcogel as a conversion-based electrode for lithium-sulfide batteries (LiSBs). The structure of the amorphous Mo3S13 chalcogel is derived through operando Raman spectroscopy, synchrotron X-ray pair distribution function (PDF), X-ray absorption near edge structure (XANES), and extended X-ray absorption fine structure (EXAFS) analysis, along with ab initio molecular dynamics (AIMD) simulations. A key feature of the three-dimensional (3D) network is the connection of Mo3S13 units through S-S bonds. Li/Mo3S13 half-cells deliver initial capacity of 1013 mAh g-1 during the first discharge. After the activation cycles, the capacity stabilizes and maintains 312 mAh g-1 at a C/3 rate after 140 cycles, demonstrating sustained performance over subsequent cycling. Such high-capacity and stability are attributed to the high density of (poly)sulfide bonds and the stable Mo-S coordination in Mo3S13 chalcogel. These findings showcase the potential of Mo3S13 chalcogels as metal-sulfide electrode materials for LiSBs.

Amorphous K-Co-Mo-Sx Chalcogel: A Synergy of Surface Sorption and Ion-Exchange.

Chalcogel represents a unique class of meso- to macroporous nanomaterials that offer applications in energy and environmental pursuits. Here, the synthesis of an ion-exchangeable amorphous chalcogel using a nominal composition of K2CoMo2S10 (KCMS) at room temperature is reported. Synchrotron X-ray pair distribution function (PDF), X-ray absorption near-edge structure (XANES), and extended X-ray absorption fine structure (EXAFS) reveal a plausible local structure of KCMS gel consisting of Mo5+ 2 and Mo4+ 3 clusters in the vicinity of di/polysulfides which are covalently linked by Co2+ ions. The ionically bound K+ ions remain in the percolating pores of the Co-Mo-S covalent network. XANES of Co K-edge shows multiple electronic transitions, including quadrupole (1s→3d), shakedown (1s→4p + MLCT), and dipole allowed 1s→4p transitions. Remarkably, despite a lack of regular channels as in some crystalline solids, the amorphous KCMS gel shows ion-exchange properties with UO2 2+ ions. Additionally, it also presents surface sorption via [S∙∙∙∙UO2 2+] covalent interactions. Overall, this study underscores the synthesis of quaternary chalcogels incorporating alkali metals and their potential to advance separation science for cations and oxo-cationic species by integrating a synergy of surface sorption and ion-exchange.

Selective and Scalable CO2 Electrolysis Enabled by Conductive Zinc Ion-Implanted Zeolite-Supported Cadmium Oxide Nanoclusters.

Catalyst supports play an essential role in catalytic reactions, hinting at pronounced metal-support effects. Zeolites are a propitious support in heterogeneous catalysts, while their use in the electrocatalytic CO2 reduction reaction has been limited as yet because of their electrically insulating nature and serious competing hydrogen evolution reaction (HER). Enlightened by theoretical prediction, herein, we implant zinc ions into the structural skeleton of a zeolite Y to strategically tailor a favorable electrocatalytic platform with remarkably enhanced electronic conduction and strong HER inhibition capability, which incorporates ultrafine cadmium oxide nanoclusters as guest species into the supercages of the tailored 12-ring window framework. The metal d-bandwidth tuning of cadmium by skeletal zinc steers the extent of substrate-molecule orbital mixing, enhancing the stabilization of the key intermediate *COOH while weakening the CO poisoning effect. Furthermore, the strong cadmium-zinc interplay causes a considerable thermodynamic barrier for water dissociation in the conversion of H+ to *H, potently suppressing the competing HER. Therefore, we achieve an industrial-level partial current density of 335 mA cm-2 and remarkable Faradaic efficiency of 97.1% for CO production and stably maintain Faradaic efficiency above 90% at the industrially relevant current density for over 120 h. This work provides a proof of concept of tailored conductive zeolite as a favorable electrocatalytic support for industrial-level CO2 electrolysis and will significantly enhance the adaptability of conductive zeolite-based electrocatalysts in a variety of electrocatalysis and energy conversion applications.

Competitive Coordination Structure Regulation in Deep Eutectic Electrolyte for Stable Zinc Batteries.

Rechargeable zinc-based batteries are finding their niche in energy storage applications where cost, safety, scalability matter, yet they are plagued by rapid performance degradation due to the lack of suitable electrolytes to stabilize Zn anode. Herein, we report a competitive coordination structure to form unique quaternary hydrated eutectic electrolyte with ligand-cation-anion cluster. Unraveled by experiment and calculation results, the competing component can enter initial primary coordination shell of Zn2+ ion, partially substituting Lewis basic eutectic ligands and reinforcing cation-anion interaction. The hydration-deficient complexes induced between competing eutectic as hydrogen bond donor-accepter and water also broaden the electrochemical window and confine free water activity. The altered coordination further leads to robust hybrid organic-inorganic enriched solid electrolyte interphase, enabling passivated surface and suppressed dendrite growth. Noticeably, stable Zn plating/stripping for 8000 cycles with high Coulombic efficiencies of 99.6 % and long cycling life of 10000 cycles for Zn-organic batteries are obtained. Even under harsh conditions (small N/P ratio, low temperature), the profits brought by the competitive eutectic electrolyte are still very prominent. This design principle leveraged by eutectic electrolytes with competitive coordination offers a new approach to improve battery performance.

Interfacial Electronic Modulation of Dual-Monodispersed Pt-Ni3S2 as Efficacious Bi-Functional Electrocatalysts for Concurrent H2 Evolution and Methanol Selective Oxidation.

Constructing the efficacious and applicable bi-functional electrocatalysts and establishing out the mechanisms of organic electro-oxidation by replacing anodic oxygen evolution reaction (OER) are critical to the development of electrochemically-driven technologies for efficient hydrogen production and avoid CO2 emission. Herein, the hetero-nanocrystals between monodispersed Pt (~ 2 nm) and Ni3S2 (~ 9.6 nm) are constructed as active electrocatalysts through interfacial electronic modulation, which exhibit superior bi-functional activities for methanol selective oxidation and H2 generation. The experimental and theoretical studies reveal that the asymmetrical charge distribution at Pt-Ni3S2 could be modulated by the electronic interaction at the interface of dual-monodispersed heterojunctions, which thus promote the adsorption/desorption of the chemical intermediates at the interface. As a result, the selective conversion from CH3OH to formate is accomplished at very low potentials (1.45 V) to attain 100 mA cm-2 with high electronic utilization rate (~ 98%) and without CO2 emission. Meanwhile, the Pt-Ni3S2 can simultaneously exhibit a broad potential window with outstanding stability and large current densities for hydrogen evolution reaction (HER) at the cathode. Further, the excellent bi-functional performance is also indicated in the coupled methanol oxidation reaction (MOR)//HER reactor by only requiring a cell voltage of 1.60 V to achieve a current density of 50 mA cm-2 with good reusability.

A new assessment method for water environment safety and its application.

The Three Gorges Reservoir area is recognized by its vast size, dense population, bustling economic and social activities along its banks, and by the significant volume of waterway traffic. These factors make it with a high risk of water pollution accidents, posing a serious threat to water environmental safety. Therefore, it is imperative to conduct a water environmental safety assessment in this region to ensure the safety of the water environment. In the present work, the Driving-Pressure-State-Impact-Response-Risk Water Environmental Safety model was proposed, and a comprehensive water environmental safety assessment system was established. The Water Environment Safety Index was introduced to measure the degree of water environment safety. This model synthesized multiple factors and their interrelationships, enabling a more accurate assessment of water environment safety. By adopting scientifically rigorous evaluation criteria, this assessment method enhanced the reliability and credibility of the results obtained. The water environment safety in the 22 counties and districts of the Three Gorges Reservoir area of Chongqing region from 2017 to 2021 was assessed in terms of temporal changes and spatial differentiation. In general, the overall water environment safety situation in the Three Gorges Reservoir area of Chongqing region is relatively safe, but a few counties/districts (such as Wanzhou District, Jiangjin District, etc.) are still in Warning. Spatially, the water environmental safety condition was relatively better in the northeast compared to the southwest. The main factors threatening water environment safety include: 1) the consequence of the Three Gorges Project, 2) severe soil erosion, 3) industrial, agricultural, and domestic pollution, and 4) frequent water pollution accidents. The present work provided a new method for conducting water environment safety assessments, which is expected to positively contribute to further research in this field.

Precise Tailoring of Lithium-Ion Transport for Ultralong-Cycling Dendrite-Free All-Solid-State Lithium Metal Batteries.

All-solid-state lithium metal batteries can address crucial challenges regarding insufficient battery cycling life and energy density. The demonstration of long-cycling dendrite-free all-solid-state lithium metal batteries requires precise tailoring of lithium-ion transport of solid-state electrolytes (SSEs). In this work, a proof of concept is reported for precise tailoring of lithium-ion transport of a halide SSE, Li3InCl6, including intragranular (within grains) but also intergranular (between grains) lithium-ion transport. Lithium-ion migration tailoring mechanism in crystals is developed by unexpected enhanced Li, In, and Cl vacancy populations and lower energy barrier for hopping. The lithium-ion transport tailoring mechanism between the grains is determined by the elimination of voids between grains and the formation of unexpected supersonic conducting grain boundaries, boosting the lithium dendrite suppression ability of SSE. Due to boosted lithium-ion conduction and dendrite-suppression ability, the all-solid-state lithium metal batteries coupled with Ni-rich LiNi0.83Co0.12Mn0.05O2 cathodes and lithium metal anodes demonstrate breakthroughs in electrochemical performance by achieving extremely long cycling life at a high current density of 0.5 C (2000 cycles, 93.7% capacity retention). This concept of precise tailoring of lithium-ion transport provides a cost, time, and energy efficient solution to conquer the remaining challenges in all-solid-state lithium-metal batteries for fast developing electric vehicle markets.

Polysulfide regulation by defect-modulated Ta3N5-x electrocatalyst toward superior room-temperature sodium-sulfur batteries.

Resolving low sulfur reaction activity and severe polysulfide dissolution remains challenging in metal-sulfur batteries. Motivated by a theoretical prediction, herein, we strategically propose nitrogen-vacancy tantalum nitride (Ta3N5-x) impregnated inside the interconnected nanopores of nitrogen-decorated carbon matrix as a new electrocatalyst for regulating sulfur redox reactions in room-temperature sodium-sulfur batteries. Through a pore-constriction mechanism, the nitrogen vacancies are controllably constructed during the nucleation of Ta3N5-x. The defect manipulation on the local environment enables well-regulated Ta 5d-orbital energy level, not only modulating band structure toward enhanced intrinsic conductivity of Ta-based materials, but also promoting polysulfide stabilization and achieving bifunctional catalytic capability toward completely reversible polysulfide conversion. Moreover, the interconnected continuous Ta3N5-x-in-pore structure facilitates electron and sodium-ion transport and accommodates volume expansion of sulfur species while suppressing their shuttle behavior. Due to these attributes, the as-developed Ta3N5-x-based electrode achieves superior rate capability of 730 mAh g-1 at 3.35 A g-1, long-term cycling stability over 2000 cycles, and high areal capacity over 6 mAh cm-2 under high sulfur loading of 6.2 mg cm-2. This work not only presents a new sulfur electrocatalyst candidate for metal-sulfur batteries, but also sheds light on the controllable material design of defect structure in hopes of inspiring new ideas and directions for future research.

Longevous Cycling of Rechargeable Zn-Air Battery Enabled by "Raisin-Bread" Cobalt Oxynitride/Porous Carbon Hybrid Electrocatalysts.

Developing commercially viable electrocatalyst lies at the research hotspot of rechargeable Zn-air batteries, but it is still challenging to meet the requirements of energy efficiency and durability in realistic applications. Strategic material design is critical to addressing its drawbacks in terms of sluggish kinetics of oxygen reactions and limited battery lifespan. Herein, a "raisin-bread" architecture is designed for a hybrid catalyst constituting cobalt nitride as the core nanoparticle with thin oxidized coverings, which is further deposited within porous carbon aerogel. Based on synchrotron-based characterizations, this hybrid provides oxygen vacancies and Co-Nx -C sites as the active sites, resulting from a strong coupling between CoOx Ny nanoparticles and 3D conductive carbon scaffolds. Compared to the oxide reference, it performs enhanced stability in harsh electrocatalytic environments, highlighting the benefits of the oxynitride. Furthermore, the 3D conductive scaffolds improve charge/mass transportation and boost durability of these active sites. Density functional theory calculations reveal that the introduced N species into hybrid can synergistically tune the d-band center of cobalt and improve its bifunctional activity. As a result, the obtained air cathode exhibits bifunctional overpotential of 0.65 V and a battery lifetime exceeding 1350 h, which sets a new record for rechargeable Zn-air battery reported so far.

Prediction and countermeasures of heavy metal copper pollution accident in the Three Gorges Reservoir Area.

In order to mitigate the hazards of water pollution in drinking water source areas (DWSAs), developing applicable models and proposing effective solutions is of paramount significance. The study developed the Heshangshan Drinking Water Source Area (HDWSA) Hydrodynamic Model, integrating Geographic Information System (GIS) into a two-dimensional hydrodynamic water quality model using FORTRAN. TECPLOT360 software (Software Tools for Numerical Simulation with Visualization) visualized contamination transportation and diffusion. The model's relative error is less than 6%, indicating its strong stability and high reliability. The HDWSA in the Three Gorges Reservoir Area (TGRA) was used as a case study, focusing on copper (Cu) as a pollutant. By regulating the flow downstream from the Xiangjiaba Reservoir, Scheduling Group 1 and Scheduling Group 2 respectively increased the flow by 4000 m3/s and 8000 m3/s. The study analyzed the spatio-temporal variations of Cu concentration following pollution accident and flow scheduling. Under accident conditions, it took 71, 61, 49, and 56 min for the Cu concentration in the study area to decrease to below the standard value (1 mg/L) during dry, falling, flood, and storage periods. Scheduling Groups 1 and 2 reduced the pollutant exceedance duration by 19-26 min and 12-18 min across the four water periods.

Cu-In Dual Sites with Sulfur Defects Toward Superior Ethanol Electrosynthesis from CO2 Electrolysis.

The electrosynthesis of multi-carbon chemicals from excess CO2 is an area of great interest for research and commercial applications. However, improving both the yield of CO2 -to-ethanol conversion and the stability of the catalyst at the same time is proving to be a challenging issue. Here we propose to stabilize active Cu(I) and In dual sites with sulfur defects through an electro-driven intercalation strategy, which leads to the delocalization of electron density that enhances orbital hybridizations between the Cu-C and In-H bonds. Hence, the energy barrier for the rate-limiting *CHO formation step is reduced toward the key *OCHCHO* formation during ethanol production, which is also facilitated by the combined Cu site enabling C-C coupling and In site with a higher oxygen affinity based on both thermodynamic and kinetic calculations. Accordingly, such dual-site catalyst achieves a high partial current density toward ethanol of 409 ± 15 mA/cm2 for over 120 hours. Furthermore, a scaled-up flow cell is assembled with an industrial-relevant current of 5.7 A for over 36 hours, in which the carbon loss is less than 2.5% and single-pass carbon efficiency is around 19%. This article is protected by copyright. All rights reserved.

Lithium-compatible and air-stable vacancy-rich Li9N2Cl3 for high-areal capacity, long-cycling all-solid-state lithium metal batteries.

Attaining substantial areal capacity (>3 mAh/cm2) and extended cycle longevity in all-solid-state lithium metal batteries necessitates the implementation of solid-state electrolytes (SSEs) capable of withstanding elevated critical current densities and capacities. In this study, we report a high-performing vacancy-rich Li9N2Cl3 SSE demonstrating excellent lithium compatibility and atmospheric stability and enabling high-areal capacity, long-lasting all-solid-state lithium metal batteries. The Li9N2Cl3 facilitates efficient lithium-ion transport due to its disordered lattice structure and presence of vacancies. Notably, it resists dendrite formation at 10 mA/cm2 and 10 mAh/cm2 due to its intrinsic lithium metal stability. Furthermore, it exhibits robust dry-air stability. Incorporating this SSE in Ni-rich LiNi0.83Co0.11Mn0.06O2 cathode-based all-solid-state batteries, we achieve substantial cycling stability (90.35% capacity retention over 1500 cycles at 0.5 C) and high areal capacity (4.8 mAh/cm2 in pouch cells). These findings pave the way for lithium metal batteries to meet electric vehicle performance demands.

Crystallization Engineering of CuNi2 S4 Ultra-Fine Nanocrystals with Optimized Band Structures for Efficient Photocatalytic Pollutant Degradation and Hydrogen Production.

The mono-dispersed cubic siegenite CuNi2 S4 ultra-fine (≈5 nm) nanocrystals are fabricated through crystallization engineering under hot injection. The strong hydroxylation on mostly exposed CuNi2 S4 (220) surface leads to the formation of multi-valence (Cu+ , Cu2+ , Ni2+ , Ni3+ ) species with unsaturated hybridization and coordination micro-environments, which can induce rich redox reactions to optimize interfacial kinetics for the adsorbed reaction intermediates. The as-synthesized CuNi2 S4 nanocrystals with ultra-small particle size and the characteristics of being highly dispersed can increase specific surface area and hydroxylated active sites, which considerably contribute to the improvement of photocatalytic activities. Experimental and theoretical studies indicate that the CuNi2 S4 with unique surface condition can properly modulate the charge density distribution and the electronic band structure, thus achieving an optimal band gap for enhancing visible light absorption. Additionally, the strong hydroxylation on CuNi2 S4 (220) surface can not only make the photocatalytic process stable in alkaline environment but also bring about an impurity level between conduction and valence band, which facilitates the separation of photo-induced charge carriers by suppressing the rapid re-combination of exited electrons and holes. The optimization of band structure should be the intrinsic reason for the efficient photocatalytic pollutant degradation and hydrogen production under visible light illumination.

A family of oxychloride amorphous solid electrolytes for long-cycling all-solid-state lithium batteries.

Solid electrolyte is vital to ensure all-solid-state batteries with improved safety, long cyclability, and feasibility at different temperatures. Herein, we report a new family of amorphous solid electrolytes, xLi2O-MCly (M = Ta or Hf, 0.8 ≤ x ≤ 2, y = 5 or 4). xLi2O-MCly amorphous solid electrolytes can achieve desirable ionic conductivities up to 6.6 × 10-3 S cm-1 at 25 °C, which is one of the highest values among all the reported amorphous solid electrolytes and comparable to those of the popular crystalline ones. The mixed-anion structural models of xLi2O-MCly amorphous SEs are well established and correlated to the ionic conductivities. It is found that the oxygen-jointed anion networks with abundant terminal chlorines in xLi2O-MCly amorphous solid electrolytes play an important role for the fast Li-ion conduction. More importantly, all-solid-state batteries using the amorphous solid electrolytes show excellent electrochemical performance at both 25 °C and -10 °C. Long cycle life (more than 2400 times of charging and discharging) can be achieved for all-solid-state batteries using the xLi2O-TaCl5 amorphous solid electrolyte at 400 mA g-1, demonstrating vast application prospects of the oxychloride amorphous solid electrolytes.

Phase Transition Engineering of Host Perovskite toward Optimal Exsolution-facilitated Catalysts for Carbon Dioxide Electrolysis.

The in situ exsolution technique of nanoparticles has brought new opportunities for the utilization of perovskite-based catalysts in solid oxide cells. However, the lack of control over the structural evolution of host perovskites during the promotion of exsolution has restricted the architectural exploitation of exsolution-facilitated perovskites. In this study, we strategically broke the long-standing trade-off phenomenon between promoted exsolution and suppressed phase transition via B-site supplement, thus broadening the scope of exsolution-facilitated perovskite materials. Using carbon dioxide electrolysis as an illustrative case study, we demonstrate that the catalytic activity and stability of perovskites with exsolved nanoparticles (P-eNs) can be selectively enhanced by regulating the explicit phase of host perovskites, accentuating the critical role of the architectures of perovskite scaffold in catalytic reactions occurring on P-eNs. The concept demonstrated could potentially pave the way for designing the advanced exsolution-facilitated P-eNs materials and unveiling a wide range of catalytic chemistry taking place on P-eNs.