Elucidating the suppression of lithium dendrite growth with a void-reduced anti-perovskite solid-state electrolyte pellet for stable lithium metal anodes

Solid-state lithium-metal batteries,with their high theoretical energy density and safety,are highly promising as a next-generation battery contender.Among the alternatives proposed as solid-state electrolyte,lithium-rich anti-perovskite(Li RAP)materials have drawn the most interest because of high theoretical Li^(+)conductivity,low cost and easy processing.Although solid-state electrolytes are believed to have the potential to physically inhibit the lithium dendrite growth,lithium-metal batteries still suffer from the lithium dendrite growth and thereafter the short circuiting.The voids in practical Li RAP pellets are considered as the root cause.Herein,we show that reducing the voids can effectively suppress the lithium dendrite growth.The voids in the pellet resulted in an irregular Li^(+)flux distribution and a poor interfacial contact with lithium metal anode;and hence the ununiform lithium dendrites.Consequently,the lithium-metal symmetric cell with void-reduced Li_(2)OHCl-HT pellet was able to display excellent cycling performance(750 h at 0.4 m A cm^(-2))and stability at high current density(0.8 m A cm^(-2)for 120 h).This study provides not only experimental evidence for the impact of the voids in Li RAP pellets on the lithium dendrite growth,but also a rational pellet fabrication approach to suppress the lithium dendrite growth.

Synthesis and Conductivity Characterization of Anti-Perovskite Na3OX Solid Electrolytes for All Solid Na-Ion Batteries

Solid electrolytes for all solid sodium-ion batteries have been attracting much attention as an alternative energy storage system, which have the advantage of being extremely safe because it can be charged quickly and is nonflammable. We have synthesized anti-perovskite type Na3OX (X = Br, and I) electrolytes with high purity, by reactions of halogen mixtures with sodium oxides. After mixing, it was filled in an alumina crucible and heated for 6 hours at 330°C. It was confirmed that a large crystal strain was introduced by eutectication, which might reduce the activation energy of Na ion conduction and lead to an improvement of the conductivity. A relatively higher ionic conductivity of σ = 1.55 × 10-7 S/cm at 60°C has been obtained for Na3OBr0.6I0.4, which is about three orders higher than that in literature. A different ratio of X (X = Br, I) ions was added into sodium oxide to make the Na3OX crystal. The influence of strain introduction on optimizing the bottleneck and improving the conductivity was discussed.

Sodium-rich volcanic rocks and their relationships with iron deposits in the Aqishan-Yamansu belt of Eastern Tianshan,NW China

The volcanic rocks hosting the iron deposits in the Aqishan–Yamansu metallogenic belt are sodium-rich.The geochronology,petrography,and geochemistry of minerals and sodium-rich rocks as well as the relationship between these rocks and the iron deposits are studied.Geochemically,the ore-hosting volcanic rocks are sodiumrich(the averages of Na2O and Na2O/K2O are 4.31 wt.%and 8.56,respectively)and belong to the calc-alkaline series.They are enriched in LREEs and LILEs(Ba,U,K,and Sr),but depleted in HFSEs(Nb,Ta,and Ti).SHRIMP zircon U–Pb dating of the crystal tuff in the Aqishan Formation and the dacite in the Tugutu Bulak Formation yields ages of 337.5
2.3 Ma(n?15,MSWD?0.85)and 313.0
3.3 Ma(n?13,MSWD?0.74),respectively,indicating that the sodium-rich volcanic rocks formed from the early–late Carboniferous.Electron microprobe data from plagioclases demonstrate that albites and/or oligoclases were formed in the basic–intermediate–acid volcanic rocks.Two stages of albitization are identified,and the latter is likely attributed to the dissolution of iron in the Aqishan–Yamansu belt.The sodium-rich volcanic rocks probably formed by the interaction between volcanic lava and seawater after volcanoes erupted on the seafloor;meanwhile,the albites formed by element substitution in a low-metamorphic environment.The spatiotemporal coupling relationship between sodium-rich volcanic rocks and iron deposits in the Aqishan–Yamansu belt is favorable.Iron dissolved from the dark minerals of basic–intermediate volcanic rocks through sodium metasomatism is one of the material sources for the iron deposits.

High capacity sodium-rich layered oxide cathode for sodium-ion batteries

Sodium-ion batteries have attracted significant recent attention currently considering the limited available lithium resource. However, the energy density of sodium-ion batteries is still insufficient compared to lithium-ion batteries, mainly because of the unavailability of high-energy cathode materials. In this work, a novel sodium-rich layered oxide material（Na_2 MnO_3） is reported with a dynamical stability similar to that of the Li_2 MnO_3 structure and a high capacity of269.69 mA·h·g1, based on first-principles calculations. Sodium ion de-intercalation and anionic reaction processes are systematically investigated, in association with sodium ions migration phenomenon and structure stability during cycling of Nax MnO3（1 ≤ x ≤ 2）. In addition, the charge compensation during the initial charging process is mainly contributed by oxygen, where the small differences of the energy barriers of the paths 2 c→4 h, 4 h→2 c, 4 h→4 h, 2 c→2 b, and 4 h→2 b indicate the reversible sodium ion occupancy in transitional metal and sodium layers. Moreover, the slow decrease of the elastic constants is a clear indication of the high cycle stability. These results provide a framework to exploit the potential of sodium-rich layered oxide, which may facilitate the development of high-performance electrode materials for sodium-ion batteries.

Effects of natural mineral-rich water consumption on the expression of sirtuin 1 and angiogenic factors in the erectile tissue of rats with fructose-induced metabolic syndrome

Consuming a high-fructose diet induces metabolic syndrome （MS）-Iike features, including endothelial dysfunction. Erectile dysfunction is an early manifestation of endothelial dysfunction and systemic vascular disease. Because mineral deficiency intensifies the deleterious effects of fructose consumption and mineral ingestion is protective against MS, we aimed to characterize the effects of 8weeks of natural mineral-rich water consumption on the structural organization and expression of vascular growth factors and receptors on the corpus cavernosum （CC） in 10% fructose-fed Sprague-Dawley rats （FRUCT）. Differences were not observed in the organization of the CC either on the expression of vascular endothelial growth factor （VEGF） or the components of the angiopoietins/Tie2 system. However, opposing expression patterns were observed for VEGF receptors （an increase and a decrease for VEGFR1 and VEGFR2, respectively） in FRUCT animals, with these patterns being strengthened by mineral-rich water ingestion. Mineral-rich water ingestion （FRUCTMIN） increased the proportion of smooth muscle cells compared with FRUCT rats and induced an upregulatory tendency of sirtuin I expression compared with the control and FRUCT groups. Western blot results were consistent with the dual immunofluorescence evaluation. Plasma oxidized low-density lipoprotein and plasma testosterone levels were similar among the experimental groups, although a tendency for an increase in the former was observed in the FRUCTMIN group. The mineral-rich water-treated rats presented changes similar to those observed in rats treated with MS-protective polyphenol-rich beverages or subjected to energy restriction, which led us to hypothesize that the effects of mineral-rich water consumption may be more vast than those directly observed in this study.

Transparent glassy composites incorporating lead-free anti-perovskite halide nanocrystals enable tunable emission and ultrastable X-ray imaging

Lead halide perovskite materials exhibit excellent scintillation performance,which,however,suffer from serious stability and toxicity problems.In contrast,the heavy metal-free anti-perovskite materials[MX_(4)]XA_(3)(A=alkali metal;M=transition metal;X=Cl,Br,I),a class of electron-inverted perovskite derivatives,exhibit robust structural and photophysical stability.Here,we design and prepare a lead-free[MnBr_(4)]BrCs_(3) anti-perovskite nanocrystal(NC)-embedded glass for efficient X-ray-excited luminescence with high-resolution X-ray imaging with a spatial resolution of 19.1 Ip mm^(-1).Due to the unique crystal structure and the protection of the glass matrix,the Cs_(3)MnBr_(5) NC-embedded glass exhibits excellent X-ray irradiation stability,thermal stability,and water resistance.These merits enable the demonstration of real-time and durable X-ray radiography based on the developed glassy composite.This work could stimulate the research and development of novel metal halide anti-perovskite materials and open a new path for future development in the field of high-resolution and ultrastable X-ray imaging.

Hierarchical sodium-rich Prussian blue hollow nanospheres as high-performance cathode for sodium-ion batteries

Recently, Prussian blue and its analogues （PBAs） have attracted tremendous attention as cathode materials for sodium-ion batteries because of their good cycling performance, low cost, and environmental friendliness. However, they still suffer from kinetic problems associated with the solid-state diffusion of sodium ions during charge and discharge processes, which leads to low specific capacity and poor rate performances. In this work, novel sodium iron hexacyanoferrate nanospheres with a hierarchical hollow architecture have been fabricated as cathode material for sodium-ion batteries by a facile template method. Due to the unique hollow sphere morpholog~ sodium iron hexacyanoferrate nanospheres can provide large numbers of active sites and high diffusion dynamics for sodium ions, thus delivering a high specific capacity （142 mAh/g）, a superior rate capabili, and an excellent cycling stability. Furthermore, the sodium insertion/extraction mechanism has been studied by in situ X-ray diffraction, which provides further insight into the crystal structure change of the sodium iron hexacyanoferrate nanosphere cathode material during charge and discharge processes.

Enhancement of–OH content on mechanical properties of antiperovskite solid electrolytes

All-solid-state batteries,renowned for their enhanced safety and high energy density,have garnered broad interest.Oxide solid electrolytes are highly anticipated for their balanced performance.However,their high Young’s modulus and inadaptability to volume change during cycling lead to poor contact and eventual battery failure.In this work,Young’s modulus of Li_(1+x)(OH)_(x)Cl samples is lowered to a level comparable to that of sulfide by regulating the–OH content.As the–OH content increases,Young’s modulus of Li_(1+x)(OH)_(x)Cl samples decreases significantly.This may be due to the local aggregation of–OH groups,forming cavities similar to LiOH structure,which reduces the bonding of the structure.On the premise of high Li-ion conductivity and electrochemical stability,the lowered Young’s modulus improves the contact between the solid electrolyte and the electrodes,forming a strong and stable interfacial layer,thereby improving interfacial and cycling stability.The symmetrical lithium metal cell shows excellent cycle performance of 600 h,and the assembled LiFePO_(4)|Li_(2.4)(OH)1.4Cl|Li cell shows significantly enhanced cycling endurance with 80%capacity retention after 150 cycles.This work not only emphasizes the crucial importance of Young’s modulus in improving interface issues but also offers innovative approaches to advance the mechanical properties of solid electrolytes.

Structure inversion asymmetry enhanced electronic structure and electrical transport in 2D A3SnO(A=Ca,Sr,and Ba)antiperovskite monolayers

Anti-perovskites A3SnO(A=Ca,Sr,and Ba)are an important class of materials due to the emergence of Dirac cones and tiny mass gaps in their band structures originating from an intricate interplay of crystal symmetry,spin–orbit coupling,and band overlap.This provides an exciting playground for modulating their electronic properties in the two-dimensional(2D)limit.Herein,we employ first-principles density functional theory(DFT)calculations by combining dispersion-corrected SCAN+rVV10 and mBJ functionals for a comprehensive side-by-side comparison of the structural,thermodynamic,dynamical,mechanical,electronic,and thermoelectric properties of bulk and monolayer(one unit cell thick)A3SnO anti-perovskites.Our results show that 2D monolayers derived from bulk A3SnO anti-perovskites are structurally and energetically stable.Moreover,Rashba-type splitting in the electronic structure of Ca3SnO and Sr3SnO monolayers is observed owing to strong spin–orbit coupling and inversion asymmetry.On the other hand,monolayer Ba3SnO exhibits Dirac cone at the high-symmetryΓpoint due to the domination of band overlap.Based on the predicted electronic transport properties,it is shown that inversion asymmetry plays an essential character such that the monolayers Ca3SnO and Sr3SnO outperform thermoelectric performance of their bulk counterparts.