Structural Engineering of Anode Materials for Low-Temperature Lithium-Ion Batteries:Mechanisms,Strategies,and Prospects

The severe degradation of electrochemical performance for lithium-ion batteries(LIBs)at low temperatures poses a significant challenge to their practical applications.Consequently,extensive efforts have been contributed to explore novel anode materials with high electronic conductivity and rapid Li^(+)diffusion kinetics for achieving favorable low-temperature performance of LIBs.Herein,we try to review the recent reports on the synthesis and characterizations of low-temperature anode materials.First,we summarize the underlying mechanisms responsible for the performance degradation of anode materials at subzero temperatures.Second,detailed discussions concerning the key pathways(boosting electronic conductivity,enhancing Li^(+)diffusion kinetics,and inhibiting lithium dendrite)for improving the low-temperature performance of anode materials are presented.Third,several commonly used low-temperature anode materials are briefly introduced.Fourth,recent progress in the engineering of these low-temperature anode materials is summarized in terms of structural design,morphology control,surface&interface modifications,and multiphase materials.Finally,the challenges that remain to be solved in the field of low-temperature anode materials are discussed.This review was organized to offer valuable insights and guidance for next-generation LIBs with excellent low-temperature electrochemical performance.

Surface engineering of P2-type cathode material targeting long-cycling and high-rate sodium-ion batteries

The widespread interest in layered P2-type Mn-based cathode materials for sodium-ion batteries(SIBs)stems from their cost-effectiveness and abundant resources.However,the inferior cycle stability and mediocre rate performance impede their further development in practical applications.Herein,we devised a wet chemical precipitation method to deposit an amorphous aluminum phosphate(AlPO_(4),denoted as AP)protective layer onto the surface of P2-type Na_(0.55)Ni_(0.1)Co_(0.7)Mn_(0.8)O_(2)(NCM@AP).The resulting NCM@5AP electrode,with a 5 wt%coating,exhibits extended cycle life(capacity retention of78.4%after 200 cycles at 100 mA g^(-1))and superior rate performance(98 mA h g^(-1)at 500 mA g^(-1))compared to pristine NCM.Moreover,our investigation provides comprehensive insights into the phase stability and active Na^(+)ion kinetics in the NCM@5AP composite electrode,shedding light on the underlying mechanisms responsible for the enhanced performance observed in the coated electrode.

Metal–Organic Gel Leading to Customized Magnetic‑Coupling Engineering in Carbon Aerogels for Excellent Radar Stealth and Thermal Insulation Performances

Metal–organic gel(MOG)derived composites are promising multi-functional materials due to their alterable composition,identifiable chemical homogeneity,tunable shape,and porous structure.Herein,stable metal–organic hydrogels are prepared by regulating the complexation effect,solution polarity and curing speed.Meanwhile,collagen peptide is used to facilitate the fabrication of a porous aerogel with excellent physical properties as well as the homogeneous dispersion of magnetic particles during calcination.Subsequently,two kinds of heterometallic magnetic coupling systems are obtained through the application of Kirkendall effect.FeCo/nitrogen-doped carbon(NC)aerogel demonstrates an ultra-strong microwave absorption of−85 dB at an ultra-low loading of 5%.After reducing the time taken by atom shifting,a FeCo/Fe3O4/NC aerogel containing virus-shaped particles is obtained,which achieves an ultra-broad absorption of 7.44 GHz at an ultra-thin thickness of 1.59 mm due to the coupling effect offered by dual-soft-magnetic particles.Furthermore,both aerogels show excellent thermal insulation property,and their outstanding radar stealth performances in J-20 aircraft are confirmed by computer simulation technology.The formation mechanism of MOG is also discussed along with the thermal insulation and electromagnetic wave absorption mechanism of the aerogels,which will enable the development and application of novel and lightweight stealth coatings.

Study on Physical and Chemical Behaviors of Rare Earths in Preparing Ceramic Tube Supported Palladium Film by Electroless Plating

The rare earths of ytterbium, lanthanum, praseodymium, neodymium and their binary mixtures were respectively added into the traditional electroless plating solution to prepare thin palladium film on the inner surface of porous ceramic tube. The experimental results shows that the addition of rare earths increases palladium deposition rates and the binary mixtures are superior to the single rare earths and the mixture of ytterbium-lanthanum is the most efficient. Adding the mixture of ytterbium-lanthanum can also reduce the plating temperature by 10 ~ 20℃, shrink the metal crystal size and improve the film densification compared to those by traditional electroless plating. A thin palladium film with 5μm was prepared and the film made a highly pure hydrogen with a molar fraction of more than 99.97% from a H2-N2 gas mixture. More attentions were paid to analyze the physical and chemical behaviors of the rare earths in palladium film preparation.

Electrochemical analysis and convection-enhanced mass transfer synergistic effect of MnO_x/Ti membrane electrode for alcohol oxidation

The different electrocatalytic reactors could be constructed for the electrocatalytic oxidation of 2,2,3,3-tetrafluoro-1-propanol(TFP) with two typical MnO_x/Ti electrodes, i.e.the electrocatalytic membrane reactor(ECMR) with the Ti membrane electrode and the electrocatalytic reactor(ECR) with the traditional Ti plate electrode.For the electro-oxidation of TFP, the conversion with membrane electrode(70.1%) in the ECMR was 3.3 and 1.7 times higher than that of the membrane electrode without permeate flow(40.8%) in the ECMR and the plate electrode(21.5%) in the ECR, respectively.Obviously, the pore structure of membrane and convection-enhanced mass transfer in the ECMR dramatically improved the catalytic activity towards the electro-oxidation of TFP.The specific surface area of porous electrode was 2.22 m^2·g^(-1).The surface area of plate electrode was 2.26 cm^2(1.13 cm^2× 2).In addition, the electrochemical results showed that the mass diffusion coefficient of the MnO_x/Ti membrane electrode(1.80 × 10^(-6) cm^2·s^(-1)) could be increased to 6.87 × 10^(-6) cm^2·s^(-1) at the certain flow rate with pump, confirming the lower resistance of mass transfer due to the convection-enhanced mass transfer during the operation of the ECMR.Hence, the porous structure and convection-enhanced mass transfer would improve the electrochemical property of the membrane electrode and the catalytic performance of the ECMR,which could give guideline for the design and application of the porous electrode and electrochemical reactor.

Green synthesis of ZSM-5 using silica fume and catalytic co-cracking of lignin and plastics for production of monocyclic aromatics

ZSM-5 with hierarchical pore structure was synthesized by a simple two-step hydrothermal crystallization from silica fume without using any organic ammonium templates.The synthesized ZSM-5 were oval shaped particles with a particle size about 2.0 μm and weak acid-dominated with proper Brønsted(B)and Lewis(L)acid sites.The ZSM-5 was used for catalytic co-cracking of n-octane and guaiacol,lowdensity polyethylene(LDPE)and alkali lignin(AL)to enhance the production of benzene,toluene,ethylbenzene and xylene(BTEX).The most significant synergistic effect occurred at n-octane/guaiacol at 1:1 and LDPE/AL at 1:3,under the condition,the achieved BTEX selectivity were 24%and 33%(mass)higher than the calculated values(weighted average).The highest BTEX selectivity reached 88.5%,which was 3.7%and 54.2%higher than those from individual cracking LDPE and AL.The synthesized ZSM-5 exhibited superior catalytic performance compared to the commercial ZSM-5,indicating potential application prospect.

Effects of river damming on biogenic silica turnover:implications for biogeochemical carbon and nutrient cycles

Rivers link terrestrial ecosystems and marine ecosystems, and they transport large amounts of substances into oceans each year, including several forms of silicon(Si), carbon(C), and other nutrients. However, river damming affects the water flow and biogeochemical cycles of Si, C, and other nutrients through biogeochemical interacting processes. In this review, we first summarize the current understanding of the effects of river damming on the processes of biogeochemical Si cycle, especially the source, composition, and recycling process of biogenic silica(BSi). Then, we introduce dam impacts on the cycles of C and some other nutrients. Dissolved silicon in rivers is mainly released from phytolith dissolution and silicate weathering. BSi in suspended matter or sediments in most rivers mainly consists of phytoliths and mainly originates from soil erosion. However, diatom growth and deposition in many reservoirs formed by river interception may significantly increase the contribution of diatom Si to total BSi, and thus significantly influence the biogeochemical Si,C, and nutrient cycles. Yet the turnover of phytoliths and diatoms in different rivers formed by river damming is still poorly quantified. Thus, they should be further investigated to enhance our understanding about the effects of river damming on global biogeochemical Si, C and nutrient cycles.

Electrochemical Carbon Dioxide Reduction to Ethylene:From Mechanistic Understanding to Catalyst Surface Engineering

Electrochemical carbon dioxide reduction reaction(CO_(2)RR)provides a promising way to convert CO_(2)to chemicals.The multicarbon(C_(2+))products,especially ethylene,are of great interest due to their versatile industrial applications.However,selectively reducing CO_(2)to ethylene is still challenging as the additional energy required for the C–C coupling step results in large overpotential and many competing products.Nonetheless,mechanistic understanding of the key steps and preferred reaction pathways/conditions,as well as rational design of novel catalysts for ethylene production have been regarded as promising approaches to achieving the highly efficient and selective CO_(2)RR.In this review,we first illustrate the key steps for CO_(2)RR to ethylene(e.g.,CO_(2)adsorption/activation,formation of~*CO intermediate,C–C coupling step),offering mechanistic understanding of CO_(2)RR conversion to ethylene.Then the alternative reaction pathways and conditions for the formation of ethylene and competitive products(C_1 and other C_(2+)products)are investigated,guiding the further design and development of preferred conditions for ethylene generation.Engineering strategies of Cu-based catalysts for CO_(2)RR-ethylene are further summarized,and the correlations of reaction mechanism/pathways,engineering strategies and selectivity are elaborated.Finally,major challenges and perspectives in the research area of CO_(2)RR are proposed for future development and practical applications.

Synthesis and electrochemical performance of La-doped Li_3V_(2-x)La_x(PO_4)_3 cathode materials for lithium batteries

La-doped Li3V2-xLax（PO4）3 （ x = 0.01, 0.02, and 0.03） cathode materials for lithium ion batteries were synthesized by the microwave-assisted carbothermal reduction method （MW-CTR）. The structures and properties of the prepared samples were investigated by X-ray diffraction （XRD） and electrochemical measurements. The results showed that all the three Li3V2-xLax（PO4）3 samples had the same monocfinic structures and sharper diffraction peaks of the crystal plane compared with those of the undoped Li3V2（PO4）3. The initial charge/discharge specific capacity, coulomb efficiency, and discharge decay rate of all the three Li3V2-xLax（PO4）3 samples were superior to those of the undoped Li3V2（PO4）3 sample, and the Li3V1.98La0.02（PO4）3 sample exhibited the best features among the three La-doped Li3V2-xLax（PO4）3 samples. Electrochemical impedance spectroscopy （EIS） demonstrated that the Li3V1.98Lao.02（PO4）3 sample had a lower charge transfer resistance and a higher Li ion diffusion coefficient compared with the undoped Li3V2 （PO4）3 sample.

Nano-Au-decorated hierarchical porous cobalt sulfide derived from ZIF-67 toward optimized oxygen evolution catalysis:Important roles of microstructures and electronic modulation

Enhancing both the number of active sites available and the intrinsic activity of Co-based electrocatalysts simultaneously is a desirable goal.Herein,a ZIF-67-derived hierarchical porous cobalt sulfide decorated by Au nanoparticles(NPs)(denoted as HP-Au@CoxSy@ZIF-67)hybrid is synthesized by low-temperature sulfuration treatment.The well-defined macroporous-mesoporous-microporous structure is obtained based on the combination of polystyrene spheres,as-formed CoxSy nanosheets,and ZIF-67 frameworks.This novel three-dimensional hierarchical structure significantly enlarges the three-phase interfaces,accelerating the mass transfer and exposing the active centers for oxygen evolution reaction.The electronic structure of Co is modulated by Au through charge transfer,and a series of experiments,together with theoretical analysis,is performed to ascertain the electronic modulation of Co by Au.Meanwhile,HP-Au@CoxSy@ZIF-67 catalysts with different amounts of Au were synthesized,wherein Au and NaBH4 reductant result in an interesting“competition effect”to regulate the relative ratio of Co^(2+)/Co^(3+),and moderate Au assists the electrochemical performance to reach the highest value.Consequently,the optimized HP-Au@CoxSy@ZIF-67 exhibits a low overpotential of 340 mV at 10 mA cm^(-2)and a Tafel slope of 42 mV dec-1 for OER in 0.1 M aqueous KOH,enabling efficient water splitting and Zn-air battery performance.The work here highlights the pivotal roles of both microstructural and electronic modulation in enhancing electrocatalytic activity and presents a feasible strategy for designing and optimizing advanced electrocatalysts.

Discrimination of polysorbate 20 by high-performance liquid chromatography-charged aerosol detection and characterization for components by expanding compound database and library

Analyzing polysorbate 20(PS20)composition and the impact of each component on stability and safety is crucial due to formulation variations and individual tolerance.The similar structures and polarities of PS20 components make accurate separation,identification,and quantification challenging.In this work,a high-resolution quantitative method was developed using single-dimensional high-performance liquid chromatography(HPLC)with charged aerosol detection(CAD)to separate 18 key components with multiple esters.The separated components were characterized by ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UHPLC-Q-TOF-MS)with an identical gradient as the HPLC-CAD analysis.The polysorbate compound database and library were expanded over 7-time compared to the commercial database.The method investigated differences in PS20 samples from various origins and grades for different dosage forms to evaluate the composition-process relationship.UHPLC-Q-TOF-MS identified 1329 to 1511 compounds in 4 batches of PS20 from different sources.The method observed the impact of 4 degradation conditions on peak components,identifying stable components and their tendencies to change.HPLC-CAD and UHPLC-Q-TOF-MS results provided insights into fingerprint differences,distinguishing quasi products.

Recent progress and future prospects of high-entropy materials for battery applications

Due to the energy crisis caused by limited fossil fuel reserves,extensive use of the renewable energy sources such as wind or solar energy is deemed to replace the use of traditional fossil fuels in the future^([1−3]).However,most renewable energy sources face the same problem,which is the intermittency of energy.For example,solar energy cannot be utilized at night.That means the continuous energy demand required for large-scale power grids can’t be satisfied by a single solar panel model.

Research Progress on Distribution,Sources and Ecological Effects of Phthalate in Soil

Phthalate esters(PAEs)are widely used as main plasticizers in plastic products,agricultural regulators,toys,and other fields.This paper reviewed the research progress on the distribution,sources,and ecological effects of PAEs.The effects of PAEs on soil microorganisms,animals,plants and soil properties were explored in sequence,providing effective theoretical basis for future research on PAEs.

Pathway and Countermeasure of Farmers' Livelihood Transformation in the Ecological Development Area of Northern Guangdong Province from the Perspective of Ecological Protection

[Objectives]To explore pathways and countermeasures for transforming farmers livelihoods in the way of reducing their dependence on land while promoting sustainable development and alleviating ecological degradation.[Methods]A combination of field research,literature review,and policy analysis was employed to identify key factors affecting farmers livelihoods and potential strategies for transformation.[Results]The study found that developing ecological agriculture and modern agriculture,promoting agricultural transformation and upgrading,cultivating alternative industries,strengthening ecological engineering construction,and establishing diversified ecological compensation methods and supporting policies are effective strategies for transforming farmers livelihoods.[Conclusions]Implementing these strategies can help alleviate the contradiction between ecological protection and farmers livelihood development,promoting coordinated development of both.This approach not only benefits farmers but also contributes to sustainable environmental management and biodiversity conservation.

Non-target Screening and Quantitation of Organic Chlorides in Oilfield Chemicals with Comprehensive Two Dimensional Gas Chromatography Coupled with Time of Flight Mass Spectrometry

Advanced analytical methodology based on comprehensive two-dimensional gas chromatography-time of flight mass spectrometry(GC×GC-TOFMS) is proposed for investigation of organic chlorides in different oilfield chemicals.The target screening was initially carried out on 8 suspected organic chlorides by evaluating the capability of the enhanced separation and reliable identification at a trace concentration. GC×GC-TOFMS allowed for the fast and automated analysis of organic chlorides at a level of 200 μg/L. This method was subsequently applied for non-target screening of organic chlorides in different oilfield chemicals at various locations across China. 22 organic chlorides were identified and verified by comparison with pure standards in the mixed sample. Finally, this method was used to determine the content of the organic chlorides in individual samples. The result showed that the organic chloride levels in 19 of the 39 tested oilfield chemicals were above the threshold limit of 1.0 mg/L.

Screening of Polyphosphate Accumulating Organisms and Their Phosphorus Removal Performance

[Objectives]To study the phosphorus removal performance of phosphate accumulating organisms(PAOs).[Methods]Activated sludge from domestic sewage treatment plant was used as the strain source,and phosphate accumulating organisms were screened by plate streaking method and dilution coating plate method.Six kinds of excellent phosphate accumulating organisms were obtained by metachromatic granule staining experiment,total phosphorus experiment and simulated sewage phosphorus removal experiment to assist the observation of bac-terial morphology and experiment of phosphorus removal capacity.In addition,the influencing factors of phosphorus removal capacity(nitrogen source,trace metal ions)were analyzed.[Results]In the case of simulated sewage,the phosphorus removal rate of strain b was the highest,reaching 66.25%,while the phosphorus removal rate of strain e and f was about 10%lower than that of the phosphorus uptake experiment.[Conclusions]This study is expected to provide a theoretical reference for the gradual optimization of the screening method of phosphorus re-moval bacteria in domestic sewage treatment.

Designing Electronic Structures of Multiscale Helical Converters for Tailored Ultrabroad Electromagnetic Absorption

Atomic-scale doping strategies and structure design play pivotal roles in tailoring the electronic structure and physicochemical property of electromagnetic wave absorption(EMWA)materials.However,the relationship between configuration and electromagnetic(EM)loss mechanism has remained elusive.Herein,drawing inspiration from the DNA transcription process,we report the successful synthesis of novel in situ Mn/N co-doped helical carbon nanotubes with ultrabroad EMWA capability.Theoretical calculation and EM simulation confirm that the orbital coupling and spin polarization of the Mn–N4–C configuration,along with cross polarization generated by the helical structure,endow the helical converters with enhanced EM loss.As a result,HMC-8 demonstrates outstanding EMWA performance,achieving a minimum reflection loss of−63.13 dB at an ultralow thickness of 1.29 mm.Through precise tuning of the graphite domain size,HMC-7 achieves an effective absorption bandwidth(EAB)of 6.08 GHz at 2.02 mm thickness.Furthermore,constructing macroscale gradient metamaterials enables an ultrabroadband EAB of 12.16 GHz at a thickness of only 5.00 mm,with the maximum radar cross section reduction value reaching 36.4 dB m2.This innovative approach not only advances the understanding of metal–nonmetal co-doping but also realizes broadband EMWA,thus contributing to the development of EMWA mechanisms and applications.

A Study on the Theory and Approach of Environmental Impact Assessment in General Land Use Planning

In this paper,the theory and approach of environmental impact assessment in general land use planning are studied from different aspects.First,starting from the content and concept of general land use planning,the necessity of environmental impact assessment in general land use planning is illustrated.On the basis of its evaluation theories and methodologies,it attempts to establish index system of environmental impact assessment in general land use planning,and point outs that current general land use planning requires public participation.

Some Thoughts on Network Teaching of the Environmental Hydrology in Common Colleges and Universities

In the second term of 2019-2020,colleges and universities have launched a network teaching mode due to"novel coronavirus pneumonia"epidemic.The courses in colleges and universities are diversified due to the difference of majors.For the Environmental Hydrology,students often show different degrees of interest in learning this course.Of course,each student s own situation is different.Teachers should consider a variety of factors in online classroom,pay more attention to students performance,and give appropriate guidance in time.

Recent progress and future prospects of oil-absorbing materials

Oil and organic solvent contamination, derived from oil spills and organic solvent leakage, has been recognized as one of the major environmental issues imposing a serious threat to both human and ecosystem health. Among the various presented technologies applied for oil/water separation, oil absorption process has been explored widely and offers satisfactory results especially with surface modified oil-absorbing material and/or hybrid absorbents. In this review, we summarize the recent research activities involved in the designing strategies of oil-absorbing absorbents and their application in oil absorption. Then, an extensive list of various oil-absorbing materials from literature, including polymer materials, porous inorganic materials and biomass materials, has been compiled and the oil adsorption capacities toward various types of oils and organic solvents as available in the literature are presented along with highlighting and discussing the various factors involved in the designing of oil-absorbing absorbents tested so far for oil/water separation. Finally, some future trends and perspectives in oil-absorbing material are outlined.