High-modulus solid electrolyte interphase layer with gradient composition enables long-cycle all-solid-state lithium-sulfur batteries

All-solid-state lithium-sulfur batteries(ASSLSBs) have become one of the most potential candidates for the next-generation high-energy systems due to their intrinsic safety and high theoretical energy density.However, PEO-based ASSLSBs face the dilemma of insufficient Coulombic efficiency and long-term stability caused by the coupling problems of dendrite growth of anode and polysulfide shuttle of cathode. In this work, 1,3,5-trioxane(TOX) is used as a functional additive to design a PEO-based composite solidstate electrolyte(denoted as TOX-CSE), which realizes the stable long-term cycle of an ASSLSB. The results show that TOX can in-situ decompose on the anode to form a composite solid electrolyte interphase(SEI) layer with rich-organic component. It yields a high average modulus of 5.0 GPa, greatly improving the mechanical stability of the SEI layer and thus inhibiting the growth of dendrites. Also,the robust SEI layer can act as a barrier to block the side reaction between polysulfides and lithium metal.As a result, a Li-Li symmetric cell assembled with a TOX-CSE exhibits prolonged cycling stability over 2000 h at 0.2 m A cm^(-2). The ASSLSB also shows a stable cycling performance of 500 cycles at 0.5 C.This work reveals the structure–activity relationship between the mechanical property of interface layer and the battery's cycling stability.

Status and prospect of garnet/polymer solid composite electrolytes for all-solid-state lithium batteries

Solid polymer electrolytes(SPEs), such as polyethylene oxide(PEO), are characteristic of good flexibility and excellent processability, but they suffer from low ionic conductivity and small Li+transference number at ambient temperature. Inorganic solid electrolytes(ISEs), garnet-type Li7La3Zr2O12 and its derivatives(LLZO-based) in particular, possess high ionic conductivity at room temperature, wide electrochemical stability window, large Li+transference number as well as good stability against Li metal anode.Nevertheless, lithium dendrites growth, interfacial contact issue and brittle nature of LLZO-based ceramic electrolytes prevent their practical applications. In response to these shortcomings, LLZO-based/polymer solid composite electrolytes(SCEs), taking complementary advantages of two kinds of electrolytes, and thus simultaneously improving the electrode wettability, ionic conductivity and mechanical strength, have been made to develop high-performance SCEs in recent years. Herein, the intrinsic properties and research progress of LLZO-based/polymer SCEs, including LLZO-based/PEO SCEs(LLZO-based/PEO SCEs with uniform dispersion of LLZO-based fillers and LLZO-based/PEO layered SCEs) and LLZO-based/novel polymers SCEs, are summarized. Besides, comprehensive updates on their applications in solid-state batteries are also presented. Finally, challenges and perspectives of LLZO-based/polymer SCEs for advanced allsolid-state lithium batteries(ASSLBs) are suggested. This review paper aims to provide systematic research progress of LLZO-based/polymer SCEs, to allow for more efficient and target-oriented research on improving LLZO-based/polymer SCEs.

LiF and LiNO_(3) as synergistic additives for PEO-PVDF/LLZTO-based composite electrolyte towards high-voltage lithium batteries with dualinterfaces stability

Solid electrolytes with desirable properties such as high ionic conductivity,wide electrochemical stable window,and suitable mechanical strength,and stable electrode-electrolyte interfaces on both cathode and anode side are essential for high-voltage all-solid-state lithium batteries(ASSLBs)to achieve excellent cycle stability.In this work,a novel strategy of using LiF and LiNO_(3) as synergistic additives to boost the performance of PEO-PVDF/LLZTO-based composite solid electrolytes(CSEs)is developed,which also promotes the assembled high-voltage ASSLBs with dual-interfaces stability characteristic.Specifically,LiF as an inactive additive can increase the electrochemical stability of the CSE under high cut-off voltage,and improve the high-voltage compatibility between cathode and CSE,thus leading to a stable cathode/CSE interface.LiNO_(3) as an active additive can lead to an enhanced ionic conductivity of CSE due to the increased free-mobile Li+and ensure a stable CSE/Li interface by forming stable solid electrolyte interphase(SEI)on Li anode surface.Benefiting from the improved performance of CSE and stable dualinterfaces,the assembled NCM622/9[PEO_(15)-LiTFSI]-PVDF-15 LLZTO-2 LiF-3 LiNO_(3)/Li cell delivers a high rate capacity of 102.1 mAh g^(-1) at 1.0 C and a high capacity retention of 77.4%after 200 cycles at 0.5 C,which are much higher than those of the ASSLB assembled with additive-free CSE,with only 60.0 mAh g^(-1) and 52.0%,respectively.Furthermore,novel cycle test modes of resting for 5 h at different charge states after every 5 cycles are designed to investigate the high-voltage compatibility between cathode and CSE,and the results suggest that LiF additive can actually improve the high-voltage compatibility of cathode and CSE.All the obtained results confirm that the strategy of using synergistic additives in CSE is an effective way to achieve high-voltage ASSLBs with dual-interfaces stability.

Hybrid classification of coal and biomass by laser-induced breakdown spectroscopy combined with K-means and SVM

Laser-induced breakdown spectroscopy(LIBS) is a new technology suitable for classification of various materials. This paper proposes a hybrid classification scheme for coal, municipal sludge and biomass by using LIBS combined with K-means and support vector machine(SVM)algorithm. In the study, 10 samples were classified in 3 groups without supervision by K-means clustering, then a further supervised classification of 6 kinds of biomass samples by SVM was carried out. The results show that the comprehensive accuracy of the hybrid classification model is over 98%. In comparison with the single SVM classification model, the hybrid classification model can save 58.92% of operation time while guaranteeing the accuracy. The results demonstrate that the hybrid classification model is able to make an efficient, fast and accurate classification of coal, municipal sludge and biomass, furthermore, it is precise for the detection of various kinds of biomass fuel.

Preface

This is a Special Issue selected from the papers presented at the 6th Global Chinese Symposium of Chemical Engineering,held on campus of the Hong Kong University of Science and Technology,16-19 July 2014.Nearly 100 participants from eight countries and regions participated the symposium including accomplished Chinese scholars from US,UK,Canada,Australia,Singapore,China's Mainland,Taiwan and HK.The first symposium was held in Canada Chaired by Jesse Zhu of

Competing reduction induced homogeneous oxygen doping to unlock MoS_(2)basal planes for faster polysulfides conversion

The parasitic polysulfides shuttle effect greatly hinders the practical application of lithium sulfur batteries,and this issue can be addressed by promoting polysulfides conversion with catalytic materials such as Mo S_(2).However,the catalytic activity of Mo S_(2)mainly relies on edge sites,but is limited by inert basal planes.We herein report a novel,facile,ethylene glycol enabled competing reduction strategy to dope Mo S_(2)homogeneously with oxygen atoms so that its inert basal planes can be unlocked.Ethylene glycol works as a reducing agent and competes with thiourea to react with ammonium molybdate,leading to insufficient sulfuration of Mo,and consequent formation of O-Mo S_(2).Our theoretical and experimental investigations indicate that the homogeneously distributed O dopants can create abundant adsorption/-catalytic sites in the Mo S_(2)basal planes,enlarge the inter-plane distance to promote ion transport,and thus enhance the catalytic conversion of polysulfides.The oxygen doped Mo S_(2)(O-Mo S_(2))is supported on carbon nanosheets(CNS)and the composite(O-Mo S_(2)/CNS)is employed to modify the separator of Li-S battery.It gives the battery an initial discharge capacity of 1537 m Ah g-1at 0.2 C,and the battery retains a discharge capacity of 545 m Ah g-1after ultra-long 2000 cycles at 1 C,corresponding to a very small cyclic decay rate of 0.0237%.Even under a raising sulfur loading of 8.2 mg cm^(-2),the Li-S battery also delivers a high discharge capacity(554 m Ah g^(-1))with outstanding cycle stability(84.6%capacity retention)after 100 cycles at 0.5 C.Our work provides a novel,facile approach to fabricate highly catalytically active oxygen-doped Mo S_(2)for advanced Li-S batteries.

Numerical investigation on freeze-drying of aqueous material frozen with pre-built pores

Freeze-drying of the initially porous frozen material with pre-built pores from liquid material was found experimentally to save drying time by over 30% with an initial saturation being 0.28 compared with the conventional operation with the initial saturation being 1, using mannitol as the solid material. In order to understand the mass and heat transfer phenomena of this novel process, a two-dimensional mathematical model of coupled mass and heat transfer was derived with reference to the cylindrical coordinate system. Three adsorption–desorption equilibrium relationships between the vapour pressure and saturation value namely, power-law, Redhead's style and Kelvin's style equation, were tested. Kelvin's style in exponential form of adsorption equilibrium relation gave an excellent agreement between the model prediction and experimental measurement when the equation parameter, γ, of 5000 was applied. Analyses of temperature and ice saturation profiles show that additional heat needs to be supplied to increase the sample temperature in order to promote the desorption process. Simulation also shows that there is a threshold initial porosity after which the drying time decreased with the increase in the initial porosity. Enhanced freeze-drying is expected to be achieved by simultaneously enhancing mass and heat transfer of the process.

A Preliminary Study on Fertilization Biology between Epinephelus coioides(♀) and Epinephelus lanceolatus(♂)

Crossbreeding between Epinephelas coioides （ ♀ ） and Epinephelus lanceolatus （♂） was conducted by artificial insemination. Fertilized eggs were col- lected at 0, 30, 90 s, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 min post-insemination respectively, which were fixed by Smith＇s solution, embedded by paraffins and stained by H.E. According to the characteristics of Epinephelus coioides eggs, tissue section method was modified. The results showed that the sperms of Epinephelus lanceolatus rapidly entered the eggs of Epinephelus coioides at 30 s - 1 rain post-insemination. Observation results of tissue sections showed that mature eggs of Epinephelus coioides remained at metaphase of secondary maturation division. The eggs were activated after sperm penetration into the egg. With the develop- ment of secondary maturation division, at 2 rain post-insemination, eggs reached the metaphase of secondary maturation division ; at 3 - 6 rain post-insemination, sperm asters appeared; at 5 min post-insemination, eggs extruded secondary polar body; at 7 -15 rain post-insemination, male pronucleus and female pronucleus moved closer to each other and fused finally, forming a clear junction line; subsequently, zygote nucleus formed and karyotheca became faint; at 15 min pest-insem- ination, first karvokinetic division was develoued.

Commercially Viable Hybrid Li-Ion/Metal Batteries with High Energy Density Realized by Symbiotic Anode and Prelithiated Cathode

The energy density of commercial lithium(Li)ion batteries with graphite anode is reaching the limit.It is believed that directly utilizing Li metal as anode without a host could enhance the battery’s energy density to the maximum extent.However,the poor reversibility and infinite volume change of Li metal hinder the realistic implementation of Li metal in battery community.Herein,a commercially viable hybrid Li-ion/metal battery is realized by a coordinated strategy of symbiotic anode and prelithiated cathode.To be specific,a scalable template-removal method is developed to fabricate the porous graphite layer(PGL),which acts as a symbiotic host for Li ion intercalation and subsequent Li metal deposition due to the enhanced lithiophilicity and sufficient ion-conducting pathways.A continuous dissolution-deintercalation mechanism during delithiation process further ensures the elimination of dead Li.As a result,when the excess plating Li reaches 30%,the PGL could deliver an ultrahigh average Coulombic efficiency of 99.5% for 180 cycles with a capacity of 2.48 m Ah cm^(-2) in traditional carbonate electrolyte.Meanwhile,an air-stable recrystallized lithium oxalate with high specific capacity(514.3 m Ah g^(-1))and moderate operating potential(4.7-5.0 V)is introduced as a sacrificial cathode to compensate the initial loss and provide Li source for subsequent cycles.Based on the prelithiated cathode and initial Li-free symbiotic anode,under a practical-level3 m Ah capacity,the assembled hybrid Li-ion/metal full cell with a P/N ratio(capacity ratio of Li Ni_(0.8)Co_(0.1)Mn_(0.1)O_(2) to graphite)of 1.3exhibits significantly improved capacity retention after 300 cycles,indicating its great potential for high-energy-density Li batteries.

纺织废水的处理:均相催化湿气氧化

我们进行了一系列的试验，并找到了在一定温度和压力下能提高纺织废水湿空气氧化反应速率的催化剂。废水的种类包括天然纤维脱浆废水、合成纤维脱浆废水和印染废水。实验结果表明：所有被试验的催化剂均能显著提高化学需氧量(COD)和总有机碳(TOC)去除率及总COD和TOC去除量。在所有测试的催化剂中，铜盐的效果最好。盐溶液中的阴离子在催化过程中起着十分重要的作用。硝酸根离子的催化效果比硫酸根离子要强。同样地，硝酸铜的催化性能比硫酸铜要强。不同金属盐的混合物的催化性能要强于单盐的催化性能。

Variation of resistance and infectivity between Pseudomonas fluorescens SBW25 and bacteriophage Ф2 and its therapeutic implications

Dear Editor,Studies of the coevolutionary dynamics between Pseudomonas fluorescens SBW25 and bacteriophageФ2 can explore host resistance and parasite infectivity with applications in the ecological and therapeutic fields.Coevolutionary dynamics determine the efficacy of phage-based therapy.In the study described here,bacterial resistance and phage infectivity fluctuated with culture

Flag-Transitive 6-(v, k, 2) Designs

The automorphism group of a flag-transitive 6–(v, k, 2) design is a 3-homogeneous permutation group. Therefore, using the classification theorem of 3–homogeneous permutation groups, the classification of flag-transitive 6-(v, k,2) designs can be discussed. In this paper, by analyzing the combination quantity relation of 6–(v, k, 2) design and the characteristics of 3-homogeneous permutation groups, it is proved that: there are no 6–(v, k, 2) designs D admitting a flag transitive group G ≤ Aut (D) of automorphisms.

Pricing European Call Currency Option Based on Fuzzy Estimators

In this paper we present an application of fuzzy estimators method to price European call currency option. We make use of fuzzy estimators for the volatility of exchange rate which based on statistical data to obtain the fuzzy pattern of G-K model. A numerical example is presented to get the -level closed intervals of the European call currency option fuzzy price.

Exfoliation of bulk 2H-MoS_(2)into bilayer 1T-phase nanosheets via ether-induced superlattices

The exfoliation of bulk 2H-molybdenum disulfide(2H-MoS_(2))into few-layer nanosheets with 1T-phase and controlled layers represents a daunting challenge towards the device applications of MoS_(2).Conventional ion intercalation assisted exfoliation needs the use of hazardous n-butyllithium and/or elaborate control of the intercalation potential to avoid the decomposition of the MoS_(2).This work reports a facile strategy by intercalating Li ions electrochemically with ether-based electrolyte into the van der Waals(vdW)channels of MoS_(2),which successfully avoids the decomposition of MoS_(2)at low potentials.The co-intercalation of Li+and the ether solvent into MoS_(2)makes a first-order phase transformation,forming a superlattice phase,which preserves the layered structure and hence enables the exfoliation of bulk 2H-MoS_(2)into bilayer nanosheets with 1T-phase.Compared with the pristine 2H-MoS_(2),the bilayer 1T-MoS_(2)nanosheets exhibit better electrocatalytic performance for the hydrogen evolution reaction(HER).This facile method should be easily extended to the exfoliation of various transition metal dichalcogenides(TMDs).

Titanium-containing high entropy oxide(Ti-HEO):A redox expediting electrocatalyst towards lithium polysulfides for high performance Li-S batteries

Since lithium sulfur(Li-S)energy storage devices are anticipated to power portable gadgets and electric vehicles owing to their high energy density(2600 Wh·kg^(-1));nevertheless,their usefulness is constrained by sluggish sulfur reaction kinetics and soluble lithium polysulfide(LPS)shuttling effects.High electrically conductive bifunctional electrocatalysts are urgently needed for Li-S batteries,and high-entropy oxide(HEO)is one of the most promising electrocatalysts.In this work,we synthesize titanium-containing high entropy oxide(Ti-HEO)(TiFeNiCoMg)O with enhanced electrical conductivity through calcining metal-organic frameworks(MOF)templates at modest temperatures.The resulting single-phase Ti-HEO with high conductivity could facilitate chemical immobilization and rapid bidirectional conversion of LPS.As a result,the Ti-HEO/S/KB cathode(with 70 wt.%of sulfur)achieves an initial discharge capacity as high as~1375 mAh·g^(-1)at 0.1 C,and a low-capacity fade rate of 0.056%per cycle over 1000 cycles at 0.5 C.With increased sulfur loading(~5.0 mg·cm^(-2)),the typical Li-S cell delivered a high initial discharge capacity of~607 mAh·g^(-1)at 0.2 C and showcased good cycling stability.This work provides better insight into the synthesis of catalytic Ti-containing HEOs with enhanced electrical conductivity,which are effective in simultaneously enhancing the LPS-conversion kinetics and reducing the LPS shuttling effect.

Chinese herbal medicine reduces mortality in patients with severe and critical coronavirus disease 2019: a retrospective cohort study

This study aimed to evaluate the efficacy of Chinese herbal medicine(CHM)in patients with severe/critical coronavirus disease 2019(COVID-19).In this retrospective study,data were collected from 662 patients with severe/critical COVID-19 who were admitted to a designated hospital to treat patients with severe COVID-19 in Wuhan before March 20,2020.All patients were divided into an exposed group(CHM users)and a control group(non-users).After propensity score matching in a 1:1 ratio,156 CHM users were matched by propensity score to 156 non-users.No significant differences in seven baseline clinical variables were found between the two groups of patients.All-cause mortality was reported in 13 CHM users who died and 36 non-users who died.After multivariate adjustment,the mortality risk of CHM users was reduced by 82.2%(odds ratio 0.178,95%CI 0.076–0.418;P<0.001)compared with the non-users.Secondly,age(odds ratio 1.053,95%CI 1.023–1.084;P<0.001)and the proportion of severe/critical patients(odds ratio 0.063,95%CI 0.028–0.143;P<0.001)were the risk factors of mortality.These results show that the use of CHM may reduce the mortality of patients with severe/critical COVID-19.

Whole genome sequencing of 10K patients with acute ischaemic stroke or transient ischaemic attack: design, methods and baseline patient characteristics

Background and purpose Stroke is the second leading cause of death worldwide and the leading cause of mortality and long-term disability in China,but its underlying risk genes and pathways are far from being comprehensively understood.We here describe the design and methods of whole genome sequencing(WGS)for 10914 patients with acute ischaemic stroke or transient ischaemic attack from the Third China National Stroke Registry(CNSR-III).Methods Baseline clinical characteristics of the included patients in this study were reported.DNA was extracted from white blood cells of participants.Libraries are constructed using qualified DNA,and WGS is conducted on BGISEQ-500 platform.The average depth is intended to be greater than 30×for each subject.Afterwards,Sentieon software is applied to process the sequencing data under the Genome Analysis Toolkit best practice guidance to call genotypes of single nucleotide variants(SNVs)and insertion-deletions.For each included subject,21 fingerprint SNVs are genotyped by MassARRAY assays to verify that DNA sample and sequencing data originate from the same individual.The copy number variations and structural variations are also called for each patient.All of the genetic variants are annotated and predicted by bioinformatics software or by reviewing public databases.Results The average age of the included 10914 patients was 62.2±11.3 years,and 31.4%patients were women.Most of the baseline clinical characteristics of the 10914 and the excluded patients were balanced.Conclusions The WGS data together with abundant clinical and imaging data of CNSR-III could provide opportunity to elucidate the molecular mechanisms and discover novel therapeutic targets for stroke.

Sodium-rich NASICON-structured cathodes for boosting the energy density and lifespan of sodium-free-anode sodium metal batteries

Rechargeable sodium metal batteries(SMBs)have emerged as promising alternatives to commercial Li-ion batteries because of the natural abundance and low cost of sodium resources.However,the overuse of metallic sodium in conventional SMBs limits their energy densities and leads to severe safety concerns.Herein,we propose a sodium-free-anode SMB(SFA-SMB)configuration consisting of a sodium-rich Na superionic conductor-structured cathode and a bare Al/C current collector to address the above challenges.Sodiated Na_(3)V_(2)(PO_(4))_(3)in the form of Na_(5)V_(2)(PO_(4))_(3)was investigated as a cathode to provide a stable and controllable sodium source in the SFA-SMB.It provides not only remarkable Coulombic efficiencies of Na plating/stripping cycles but also a highly reversible three-electron redox reaction within 1.0–3.8 V versus Na/Na+confirmed by structural/electrochemical measurements.Consequently,an ultrahigh energy density of 400 Wh kg^(-1)was achieved for the SFA-SMB with fast Na storage kinetics and impressive capacity retention of 93%after 130 cycles.A narrowed voltage window(3.0–3.8 V vs.Na/Na+)further increased the lifespan to over 300 cycles with a high retained specific energy of 320 Wh kg^(-1).Therefore,the proposed SFA-SMB configuration opens a new avenue for fabricating next-generation batteries with high energy densities and long lifetimes.

Dendrite-free and anti-corrosion Zn metal anode enabled by an artificial layer for high-performance Zn ion capacitor

Aqueous zinc energy storage devices,holding various merits such as high specific capacity and low costs,have attracted extensive attention in recent years.Nevertheless,Zn metal anodes still suffer from a short lifespan and low Coulombic efficiency due to corrosion and side reactions in aqueous electrolytes.In this paper,we construct an artificial Sn inorganic layer on Zn metal anode through a facile strategy of atom exchange.The Sn layer suppresses Zn dendrite growth by facilitating homogeneous Zn plating and stripping during charge and discharge processes.Meanwhile,the Sn protective layer also serves as a physical barrier to decrease Zn corrosion and hydrogen generation.As a result,The Sn-coated anode(Sn|Zn)exhibits a low polarization voltage(~34 mV at 0.5 mAh/cm^(2))after 800 testing hours and displays a smooth and an even surface without corrosion.Moreover,the zinc ion capacitor(Sn|Zn‖activated carbon)is assembled with an enhanced capacity of 42 mAh/g and a capacity retention of 95%after 10,000 cycles at 5 A/g.This work demonstrates a feasible approach for the commercialization of aqueous Zn-based energy storage devices.

Effects of thermal and electrical histories on structure and dielectric behaviors of(Li_(0.5)Nd_(0.5))^(2+)-modified(Bi_(0.5)Na_(0.5))TiO_(3)-BaTiO_(3) ceramics

The effect of thermal and electrical histories on structure and dielectric behaviors is studied using 0.95(Bi_(0.5)Na_(0.5))_(0.97)(Li_(0.5)Nd_(0.5))_(0.03)TiO_(3)-0.05BaTiO_(3)(abbreviated as BNTLN0.03-BT5)ceramic as a selected system.Subtle structure change caused by annealing treatment,and pronounced phase transition and domain switching by electrical poling,are observed to occur,respectively.The dielectric constant and its strong frequency dispersion in unpoled samples decrease evidently by electrical poling due to electric field-induced ordered domain.The high temperature Maxwell-Wagner relaxor behavior vanishes by annealing treatment due to the loss of electrical inhomogeneity with interface charging effects.Piezoelectric properties are improved evidently by annealing treatment at 900℃,implying a new appropriate method to improve piezoelectric properties.