A low-cost bromine-fixed additive enables a high capacity retention zinc-bromine batteries

In recent years,more and more efforts are devoting to clean energy,renewable energies in particular to achieving net zero carbon dioxide emissions[1].However,renewable energies,like solar power and wind power,are generally intermittent and random,hindering their wide application[2,3].To address this problem,there is an urgent need in effective and reliable energy storage device.

Unraveling the hydraulic properties of loess for landslide prediction:A study on variations in loess landslides in Lanzhou,Dingxi,and Tianshui,China

Loess has distinctive characteristics,leading to frequent landslide disasters and posing serious threats to the lives and properties of local re sidents.The involvement of water repre sents a critical factor in inducing loess landslides.This study focuses on three neighboring cities sequentially situated on the Loess Plateau along the direction of aeolian deposition of loess,namely Lanzhou,Dingxi,and Tianshui,which are densely populated and prone to landslide disasters.The variations in hydraulic properties,including water retention capacity and permeability,are investigated through Soil Water Characteristic Curve(SWCC)test and hydraulic conductivity test.The experimental findings revealed that Tianshui loess exhibited the highest water retention capacity,followed by Dingxi loess,while Lanzhou loess demonstrated the lowest water retention capacity.Contrastingly,the results for the saturated permeability coefficient were found to be the opposite:Tianshui loess showed the lowest permeability,whereas Lanzhou loess displayed the highest permeability.These results are supported and analyzed by scanning electron microscopy(SEM)observation.In addition,the water retention capacity is mathematically expressed using the van Genuchten model and extended to predict unsaturated hydraulic properties of loess.The experimental results exhibit a strong accordance with one another and align with the regional distribution patterns of disasters.

Dust Retention Ability of Plants as a Factor Improving Environment Air

It is well known that air in industrial cities contains a significant amount of dust particles, smoke, and toxic gases. The increased number of vehicles has a direct impact on air quality resulting in the emission of exhaust gases, and the increase of dust concentration in air. In this article, we are describing the dust retention ability of plants depending on their leaf structure. Plant species were classified into three groups according to their dust-holding capacities. Dust retaining ability of plant species in conditions of high, average and low dust conditions described.

Pedoecological Regularities of Organic Carbon Retention in Estonian Mineral Soils

Soil organic carbon (SOC) retaining capacities of epipedon (EP), subsoil (SS) and soil cover (SC) as a whole, are soil type specific. Depending on individual and sites characteristics, the generalized humus status indices of soil types (EP and SC thickness and SOC stocks) may vary. Land use and land use change primarily influence the properties and fabric of the EP, but the humus status (SOC concentration and stock, fabric of horizons) of the SS remains practically unchangeable. The mean mineral soils SOC stocks, EP quality and SOC distribution in soil profiles depend mainly on the water regime, mineral composition (texture, calcareousness), development of eluvial processes and the land use peculiarities of soils. The mean area weighted SC SOC stock of Estonian mineral soils is 99.9 Mg ha–1, thereby the mean hydromorphic soils SOC retention capacity considerably exceeds the SOC retention capacity of automorphic soils (means are accordingly 127.5 and 78.9 Mg ha–1). The sustainable management of SOC is based on adequate information about actual SOC stocks and theoretically established or optimal humus status levels of soil types. The aggregate of SOC retained in the mineral soils of Estonia (3,235,100 ha) amounts to 323 ± 46 Tg (1 Tg = 1012 g). Approximately 42% of this is sequestered into stabilized humus, 40% into instable raw-humous material and 18% into forest (grassland) floor and shallow peat layers.

Three-dimensional kagome structures in a PCL/HA-based hydrogel scaffold to lead slow BMP-2 release for effective bone regeneration

Osteoconductive function is remarkably low in bone disease in the absence of bone tissue surrounding the grafting site,or if the bone tissue is in poor condition.Thus,an effective bone graft in terms of both osteoconductivity and osteoinductivity is required for clinical therapy.Recently,the three-dimensional(3D)kagome structure has been shown to be advantageous for bone tissue regeneration due to its mechanical properties.In this study,a polycaprolactone(PCL)kagome-structure scaffold containing a hyaluronic acid(HA)-based hydrogel was fabricated using a 3D printing technique.The retention capacity of the hydrogel in the scaffold was assessed in vivo with a rat calvaria subcutaneous model for 3 weeks,and the results were compared with those obtained with conventional 3D-printed PCL grid-structure scaffolds containing HA-based hydrogel and bulk-type HA-based hydrogel.The retained hydrogel in the kagome-structure scaffold was further evaluated by in vivo imaging system analysis.To further reinforce the osteoinductivity of the kagome-structure scaffold,a PCL kagome-structure scaffold with bone morphogenetic protein-2(BMP-2)containing HA hydrogel was fabricated and implanted in a calvarial defect model of rabbits for 16 weeks.The bone regeneration characteristics were evaluated with hematoxylin and eosin(H&E),Masson’s trichrome staining,and micro-CT image analysis.

Preparation of carbon-based material with high water absorption capacity and its effect on the water retention characteristics of sandy soil

Biochar has the potential to provide a multitude of benefits when used in soil remediation and increasing soil organic matter enrichment.Nevertheless,the intricated,hydrophobic pores and groups weaken its water-holding capacity in dry,sandy soils in arid lands.In order to combat this issue,starch-carbon-based material(SB),sodium alginate-carbon-based material(SAB),and chitosan-carbon-based material(CB)have been successfully synthesized through the graft-polymerization of biochar(BC).A series of soil column simulations were used to scrutinize the microstructure of the carbon-based material and explore its water absorption properties and its effects on sandy soil water infiltration,water retention,and aggregation.The results indicated that SB,SAB,and CB achieved water maximum absorption rates of 155,188,and 172 g g^(−1),respectively.Considering their impact on sandy soils,SB,SAB,and CB lengthened infiltration times by 1920,3330,and 3880 min,respectively,whilst enhancing the water retention capabilities of the soil by 18%,25%,and 23%in comparison to solely adding BC.The utilization of these innovative materials notably encouraged the formation of sandy soil aggregates ranging from 2.0 to 0.25 mm,endowing the aggregates with enhanced structural stability.Findings from potting experiments suggested that all three carbonbased materials were conducive to the growth of soybean seeds.Thus,it is evident that the carbon-based materials have been fabricated with success,and they have great potential not only to significantly augment the water retention capacities and structural robustness of sandy soils in arid areas,but also to bolster the development of soil aggregates and crop growth.These materials possess significant application potential for enhancing the quality of sandy soils in arid and semi-arid regions.

Synthesis, characterization and electrochemical performance of AlF_3-coated Li_(1.2)(Mn_(0.54)Ni_(0.16)Co_(0.08))O_2 as cathode for Li-ion battery

Li-rich layered transitional metal oxide Li1.2(Mn0.54Ni0.16Co0.08)O2 was prepared by sol-gel method and further modified by AlF3 coating via a wet process. The bare and AlF3-coated Li1.2(Mn0.54Ni0.16Co0.08)O2 samples were characterized by X-ray diffraction(XRD), scanning electron microscope(SEM), and high resolution transmission electron microscope(HRTEM). XRD results show that the bare and AlF3-coated samples have typical hexagonal α-Na Fe O2 structure, and AlF3-coated layer does not affect the crystal structure of the bare Li1.2(Mn0.54Ni0.16Co0.08)O2. Morphology measurements present that the AlF3 layer with a thickness of 5-7 nm is coated on the surface of the Li1.2(Mn0.54Ni0.16Co0.08)O2 particles.Galvanostatic charge-discharge tests at various rates show that the AlF3-coated Li1.2(Mn0.54Ni0.16Co0.08)O2 has an enhanced electrochemical performance compared with the bare sample. At 1C rate, it delivers an initial discharge capacity of 208.2 m A·h/g and a capacity retention of 72.4% after 50 cycles, while those of the bare Li1.2(Mn0.54Ni0.16Co0.08)O2 are 191.7 m A·h/g and 51.6 %, respectively.

Influence of graphene oxide on electrochemical performance of Si anode material for lithium-ion batteries

We have developed a Si/graphene oxide electrode synthesized via ultrasonication-stirring method under alkaline condition. Scanning electron microscopy(SEM), transmission electron microscope(TEM), EDS dot-mapping and high-resolution transmission electron microscopy(HRTEM) results show that Si particles are evenly dispersed on the graphene oxide sheets. The electrochemical performance was investigated by galvanostatic charge/discharge tests at room temperature. The results revealed that Si/graphene oxide electrode exhibited a high reversible capacity of 2825 mAh/g with a coulombic efficiency of 94.6%at 100 mA/g after 15 cycles and a capacity retention of 70.8% after 105 cycles at 4000 mA/g. These performance parameters show a great potential in the high-performance batteries application for portable electronics, electric vehicles and renewable energy storage.

Diethyl phenylphosphonite contributing to solid electrolyte interphase and cathode electrolyte interphase for lithium metal batteries

Lithium metal batteries have obtained increasing interest due to their high specific capacity.Nonetheless,the growth of lithium dendrites brings safety risks to batteries and further deteriorates the performance.Herein,we explore diethyl phenylphosphonite(DEPP) as the electrolyte additive to alleviate this problem.DEPP can be preferentially decomposed than carbonate solvents to form the stable interface between electrolyte and lithium anode for inhibiting the dendrite growth.As expected,the symmetrical LiIILi cells could achieve a stable cycling performance with 200 h at 1 mA cm^(-2).Moreover,DEPP can be preferentially oxidized on the surface of lithium cobalt oxides(LiCoO_(2)) to form a dense cathode electrolyte interphase(CEI) film for suppressing the continuous oxidative decomposition of the electrolyte and eliminating the adverse effects of HF on the battery.This endows LiCoO_(2) IILi full battery with the enhanced cycling and rate performance.

Phase Structure and Cycle Stabilities of Mg_2Ni/Mm_(0.3)Ml_(0.7)Ni_(3.55)Co_(0.75)Mn_(0.4)Al_(0.3) Composite Hydrogen Storage Alloys Prepared by Two-step re-melting

Mm0.3Ml0.7Ni3.55Co0.75Mn0.4-Al0.3 alloy has high chemical activity and favorable plateaus pressure. Mg2Ni is in favor of high hydrogen storage capacity and low weight, but it is difficult to be activated. In order to improve the capacity and cycle performances of hydrogen-storage alloy electrodes, Mm0.3Ml0.7Ni3.55Co0.75Mn0.4-Al0.3-x%Mg2Ni(x=0, 5, 10, 30) composite hydrogen storage alloys prepared by two-step re-melting were investigated in this work. The influences of Mg2Ni content on the cycle stabilities were analyzed by electrochemical methods. It was observed by XRD that the main phase of all the alloys is LaNi5 and the crystal lattice parameters of LaNi5 are changed with the increasing of x value, i.e, a-axis and unit cell volume decrease and c-axis decreases nonlinearly. The c-axis of alloy with x=5 is larger than the others. With the increasing of x value, capacity retentions of the composite hydrogen storage alloys rise from 66.21% while x=0 to 82.04% while x=10, but the capacity retention of the composite alloy with 30% Mg2Ni declines because of its decreasing axial ratio. More over, the composite alloy with 5% Mg2Ni shows the best cycle stability and higher discharge capacity, and it is an appropriate candidate for battery materials.

Experimental investigation into temperature effect on hydro-mechanical behaviours of bentonite

The bentonite barrier of underground repositories for high-level radioactive waste will be hydrated by the groundwater while it is subjected to high temperatures due to the radioactive decay of the wastes. These changes of temperature affect the hydraulic and mechanical responses of bentonite, which has important effects on design and performance of repositories. The temperature influence on the hydro-mechanical behaviour of bentonite was studied in this paper by experiments, which were carried out with the Spanish FEBEX bentonite compacted at dry densities expected in the＇ repository （from 1.5 to 1.8 Mg/m^3）. The dependence of the swelling strains of bentonite on the temperature has been measured from 30℃ to 90 ℃. At high temperatures the swelling capacity of clay slightly decreases. Also, a clear decrease of swelling pressure as a function of temperature was observed for the same dry densities. Nevertheless, the deformation of bentonite is more dependent on the stress than the temperature. An increase in the permeability of water saturated bentonite with temperature has also been detected. The water retention curves of bentonite compacted at different dry densities were determined under isochoric conditions and in the range of temperatures from 20 ℃ to 120℃. For a given density and water content, the suction decreases as the temperature increases at a rate, which is larger than the one predicted on the basis of water surface tension changing with temperature. Mechanisms related to the physico-chemical interactions that take place at microscopic level, in particular the transfer of interlayer water to the macropores triggered by temperature, seem to explain qualitatively the experimental observations.

Effect of temperature on soil-water characteristics and hysteresis of compacted Gaomiaozi bentonite

Laboratory tests under different constraint conditions were carried out to obtain the soil-water retention curves(SWRCs) of highly-compacted confined/unconfined Gaomiaozi(GMZ) bentonite at 20,40 and 80 ℃,respectively. The effect of temperature on the soil-water characteristics of the highly-compacted GMZ bentonite was analyzed. The results show that the water retention capacity of the highly-compacted GMZ bentonite decreases as the temperature increases under unconfined and confined conditions. At a certain temperature,the constraint conditions have little influence on the water retention capacity of the compacted bentonite at high suction,but the water retention capacity of the confined specimen is lower than that of the unconfined specimen at low suction. Under unconfined conditions,the hysteretic behaviour of the compacted bentonite decreases with increasing temperature. At high suction(>4 MPa) ,the hysteretic behaviour of the unconfined bentonite tends to increase with the decrease of the suction. In summary,the hysteretic behaviour of the compacted bentonite is not significant.

Changes in soil properties under Eucalyptus relative to Pinus massoniana and natural broadleaved forests in South China

The ecological effects of eucalypt plantations（EPs） have garnered increasing attention.To understand their effect on soil quality at a landscape scale,and to determine whether soil quality parameters differ due to different stand types,we evaluated soil characteristics in twenty-one groups of EPs,Pinus massoniana Lamb.plantations（PMPs） and natural broadleaved forests（NBFs）across Guangdong Province,China.Both the physical characteristics of soil hydrology and the properties of soil nutrients in A and B horizons were determined.Results showed that,compared to NBFs,EPs and PMPs produced a shallower litter layer,reduced canopy density,higher soil bulk density,significantly lower total porosity,non-capillary porosity,total water volume,and hygroscopic water in the A horizon（P〈0.05）.Moreover,total N,available K,and soil organic carbon（SOC） in EPs and PMPs were significantly lower than in NBFs.EPs and PMPs did not differ significantly in N,P or K content,but PMPs had significantly lower SOC and boron in the A horizon than EPs.Low p H and poor capacity to buffer acidification generally occurred in all cover types.Both EPs and PMPs showed a decline in soil properties relative to NBFs,but EPs and PMPs exhibited no significant difference.These results indicate that actions are needed to ameliorate the potential negative effects on soil quality in forestry plantations.

Vinyltrimethylsilane as a novel electrolyte additive for improving interfacial stability of Li-rich cathode working in high voltage

Boosting the interfacial stability between electrolyte and Li-rich cathode material at high operating voltage is vital important to enhance the cycling stability of Li-rich cathode materials for high-performance Li-ion batteries.In this work,vinyltrimethylsilane as a new type of organic silicon electrolyte additive is studied to address the interfacial instability of Li-rich cathode material at high operating voltage.The cells using vinyltrimethylsilane additive shows the high capacity retention of 73.9%after 300 cycles at 1 C,whereas the cells without this kind of additive only have the capacity retention of 58.9%.The improvement of stability is mainly attributed to the additive helping to form a more stable surface film for Li-rich cathode material,thus avoiding direct contact between the electrolyte and the cathode material,slowing down the dissolution of metal ions and the decomposition of the electrolyte under high operating voltage.Our findings in this work shed some light on the design of stable cycling performance of Li-rich cathode toward advanced Li-ion batteries.

Enhanced cyclic stability of partially disordered spinel cathodes through direct fluorination with gaseous fluorine

Spinel-type cathodes are considered an optimal substitute for conventional layered oxide cathodes owing to their use of inexpensive and earth-abundant manganese as the redox-active element.Moreover,the introduction of cation disorder can effectively suppress the detrimental two-phase reaction to realize high capacities in a wide voltage range.However,the continuous capacity decay during cycles has hindered the widespread application of these cathode materials.Inorganic fluorides exhibit excellent electrochemical stability at high voltage;therefore,in this study,the direct F2 gas reaction with a partially disordered spinel cathode(Li_(1.6)Mn_(1.6)O_(3.7)F_(0.3,)LMOF1.6)was initially applied to investigate the impacts of fluorination on the surface structure and electrochemical performances.The inorganic fluorinated layer,mainly containing LiF,was distributed uniformly on the surface of LMOF1.6nanoparticles after fluorination for an appropriate time without the turbulence caused by the valency of manganese cation,which improved the capacity retention and rate capability by the suppression of structural damage,parasitic reaction,and cation dissolution.The LMOF1.6cathode fluorinated for 0.5 h exhibited a capacity of283.6 mAh·g^(-1)at 50 mA·g^(-1)and an enhanced capacity retention of 29.6%after 50 cycles in the voltage range of1.5-4.8 V,as compared to the pristine LMOF1.6 with only27.9%capacity retention.

Effect of Y,Al Co‑Doping on Hydrogen Storage Properties of La–Mg–Ni‑Based Alloys

La–Mg–Ni-based hydrogen storage alloys have excellent hydrogen storage properties.This work reports the hydrogen storage performance of a series of A_(2)B_(7)-type La_(0.96)Mg_(0.04)N_(i3.34)Al_(0.13)alloy and La_(0.96-x)Y_(x)Mg_(0.04)Ni_(3.47–0.6x)Al_(0.6x)(x=0,0.22,0.33,0.44)alloys,and explores the effect of Y and Al element combined substitution on the microstructure and hydrogen storage performance of A_(2)B_(7)-type La–Mg–Ni-based alloys.The alloys are composed of Ce_(2)Ni_(7)phase and LaNi_(5)phase.With the increase of x,the cell volume of Ce_(2)Ni_(7)phase decreases,while that of LaNi_(5)phase increases,indicating that Y atom mainly enters Ce_(2)Ni_(7)phase and Al atom mainly enters LaNi_(5)phase.An appropriate amount of co-substitution increases the hydrogen storage capacity and reduces the hydrogen absorption/desorption plateau pressure hysteresis of the alloy.When x=0.44,the hydrogen storage capacity of the alloy is 1.449 wt%,and the hysteresis coefficient is 0.302.The cell volume of Ce_(2)Ni_(7)phase and LaNi_(5)phase expands to different degrees after 20 absorption/desorption cycles.With the increase of x,the volume expansion rate decreases,and the cycle capacity retention rate also gradually decreases.This is related to the amorphization of Ce_(2)Ni_(7)phase.When x=0.22,the capacity retention rate of the alloy is 91.4%.

Mechanism exploration of enhanced electrochemical performance of single-crystal versus polycrystalline LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)

Single-crystal LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(SC-811),which offers better cycle performance compared to the polycrystalline counterpart,has received great attention.We report herein the synthesis of SC-811 with a grain size of 2-4μm by washing and reheating method,which compares with conventional polycrystalline LiNi_(0.8)-Co_(0.1)Mn_(0.1)O_(2)(PC-811).The discharge capacity of SC-811 reaches 152.1 mAh·g^(-1)after 100 cycles(86.7%capacity retention)at 1.0 C,which is much better than that of PC-811(130.2 mAh·g^(-1),73.8%capacity retention).By using multiscale characterization,the results unveil that SC-811 can not only improve the reversibility of the H2-H3 phase transitions,suppress the generation of micro-cracks and phase transformations,but also mitigate the undesired side reactions between electrode and electrolyte.Besides,the Li-O bond of SC-811 is longer than that of PC-811,which is conducive to the de-intercalation of Li-ions,thereby enhancing the structural stability.This finding provides an impressive strategy to sustain structural stability and improve the cycling life of Ni-rich layered cathodes.

The soil configuration on granite residuals affects Benggang erosion by altering the soil water regime on the slope

A permanent collapsing gully,locally called Benggang,formed on slopes with deep granite red soil and is a type of unique gully erosion widely prevalent in southern China.Three different soil configurations(SC),ie,red-transition-sandy(SC I,the transition is the soil layer between the red soil and the sandy soil layer),transition-sandy(SC II)or sandy(SC III)are usually present in the soil profile of the Benggang slope.However,little attention has been paid to impacts of SCs on the triggering of Benggang erosion.In this study,we aimed to explore the relationships between soil water content(SWC)and triggering of Benggang erosion under different SC conditions.The soil properties of different soil layers were measured and the SWC at depths of 20,40,60,and 80 cm were monitored at 5-min intervals along a typical Benggang(SC I)during 2016-2018.The SWC of Benggang slopes with different SCs were simulated by VADOSE/W model.Results showed that the red soil layer had a higher water retention capacity and shear strength than the sandy soil layer.Even if the SWC is higher(e.g.,0.42 cm^(3)/cm^(3))at red soil layer or transition layer,the corresponding shear strength is greater than that of sandy soil layer with a lower SWC(e.g.,032 cm^(3)/cm^(3)).Relationships between shear strength and SWC of different soil layers indicate that Benggang erosion is triggered by an increase in the SWC in the deep sandy layer.Results also showed that differences exist in the SWC distribution among the different SCs.The SWC is higher in topsoil than in deeper soil in SC I and SC II,while in SC III,the opposite trend is observed.These results revealed that the presence of the red soil or transition layer can reduce the infiltration of rainwater into the deep sandy layer,thus can reduce the possibility of collapse.Our results show that the SC affects the stability of the headwall,and results provide great significances to guide the mitigation of Benggang erosion.

Separation efficiency of liquid-solid undergoing vibration based on breakage of liquid bridge

Vibrating separation is a significant method for liquid-solid separation.A typical example is the vibrating screen to dewater wet granular matter.The properties of granular matter and the vibrating parameters significantly affect the separation efficiency.This study investigates the effect of vibration parameters in separation based on the breakage of large-scale liquid bridge numerically by using a calibrated simulation model.Through analysing the simulation results,the liquid bridge shape and the volume between two sphere particles for various particle sizes and particle distances were studied in the static condition under the effect of gravity.The results show a general reducing trend of liquid bridge volume when the radius ratio of two particles increases,particularly when the ratio increases to 5.Additionally,a set of vibrating motion was applied to the liquid bridge in the simulation model.A group of experiments were also performed to validate the simulation model with vibration.Then,the effect of vibrating peak acceleration,distance between spheres and radius on the separation efficiency which was reflected by the residual water were investigated.It is found that separation efficiency increased obviously with the peak acceleration and the increase slowed down after the peak acceleration over 1 m/s^(2).