Layer Distance Research Articles

Numerical analysis of stress distribution due to upper protective layer mining and its impact on gas extraction

Pressure-relief gas extraction through the floor directional long boreholes is an advanced and effective gas control technology for the upper protective layer of contiguous coal seams. This study systematically analyzed the effects of mining activities on stress distribution in the underlying strata and developed an analytical equation to calculate the permeability distribution of the protected layer under mining-induced conditions. The results indicate that the effective extraction radius of directional long boreholes increased by 186% as the mining distance of the upper protective layer extended from 50 to 150 m. Furthermore, increasing the borehole diameter from 89 to 153 mm led to a 14.8% improvement in gas extraction efficiency, while raising the negative pressure from 15 to 35 kPa resulted in a 19.6% increase in the effective extraction radius. These findings provide valuable guidance for optimizing borehole design parameters and gas extraction efficiency, ensuring safer and more effective gas control in coal mining operations.

Synthesis of {AlMo14O44}-Based Supramolecular Structures with High Proton Conductivity.

Polyoxometalates (POMs) are esteemed for their remarkable stability and exceptionally high proton conductivity, rendering them ripe for extensive exploration owing to their research significance. Herein, we synthesized two bimolybdenum-capped {AlMoVI8MoV6O44} cluster-based coordination polymers through a solvothermal method. Single-crystal X-ray diffraction analysis elucidates that H[(H2bimb)3(AlMoVI8MoV6O44)] [bimb = 1,4-bis(imidazole-1-ylmethyl)benzene, compound 1] is the POMs-organic supramolecular structure. The introduction of zinc ions into the reaction environment facilitated the connection of initially dispersed ligands, which yielded the well-ordered structure H3[Zn2(bimb)4(AlMoVI8MoV6O44)]·4H2O (compound 2) with a layer distance of 11.8 Å. The proton conductivities (σ) of two compounds were measured under conditions of 85 °C and 98% relative humidity (RH), resulting in values of 3.89 × 10-2 and 4.76 × 10-2 S·cm-1, respectively. This study presents a novel approach to fabricating POMs as proton conductors through structural design and manufacturing adjustments.

Exact analytical solution of the equations for a quasiequilibrium two-phase domain: permeability and interdendritic spacing

This study is concerned with the theoretical description of a quasi-stationary process of directional crystallization of binary melts and solutions in the presence of a quasi-equilibrium two-phase region. The quasi-equilibrium process is ensured by the fact that the system supercooling is almost completely compensated by heat released during the phase transformation. Quasi-stationarity of the process determining constancy of the crystallization rate is ensured by given temperature gradients in the solid and liquid phases. The system of heat and mass transfer equations and boundary conditions to them under these assumptions is dependent on a single spatial variable in the reference frame moving with the crystallization rate relative to a laboratory coordinate system. Exact analytical solutions to the formulated problem in parametric form are obtained. The parameter of the solution is the solid phase fraction in a two-phase region. The distributions of temperature and impurity concentration in the solid, liquid and two-phase regions of the crystallizing system, the rate of solidification, and the spatial coordinate in the two-phase region depending on the solid phase fraction in it are found. An algebraic equation for the solid phase fraction at the interface between the solid material and the two-phase region is derived. Exact analytical solutions show that the impurity concentration in the two-phase layer increases as the solid phase fraction increases. Moreover, the solid phase fraction at the interface solid phase — two phase region and its thickness increase as the temperature gradient in the solid phase and the solidification rate increase. The developed theory allows us to determine analytically the permeability of the two-phase region and a characteristic interdendritic spacing in it. Analytical solutions show that the relative permeability in the two-phase region increases from a certain value at the interface with the solid phase to unity at the interface with the liquid phase. The selection theory of stable dendritic growth allows us to determine analytically a characteristic interdendritic distance in the two-phase layer that decreases as the temperature gradient in the solid phase increases. An increase of impurity in the molten phase gives a decrease in the interdendritic spacing within a two-phase region.

Amorphous mesoporous sulfur-rich 1T/2H-MoS2 nanospheres as high-capacity cathode materials for advanced magnesium ion batteries

Two-dimensional layered-structure MoS2 has been explored as the promising cathode materials for magnesium ion batteries benefited by its wide layer distance and satisfactory capacity. However, such strong interaction between Mg2+ and MoS2 brings about the sluggish diffusion kinetics and irreversible electrochemical reaction, leading to a decreased specific capacity and poor rate capability. How to adopt its structure engineering and interface engineering to boost the Mg2+ diffusion kinetics and enhance the electrochemical reversibility of MoS2 is still a huge challenge. Herein, the amorphous sulfur-rich 1T/2H-MoS2 mesoporous nanospheres (a-MoS2+x, 0<x<1) have been developed via a facile one-pot hydrothermal route. Acted as a cathode material for magnesium ion batteries, owing to the cooperate effects of inherent rich active sites, high conductivity and wide layer distance induced by the coexistence of sulfur-rich, 1T phase and nearly amorphous features, the as-prepared a-MoS2+x demonstrates an ultra-high discharge capacity (438.7 mAh g−1 for 50 cycles at 0.1 A g−1), promising rate capability (97.6 mAh g−1 at 1.0 A g−1), and good cyclic stability (110 cycles at 0.5 A g−1), superior to the crystalline MoS2 (c-MoS2) and other previously reported MoS2 counterparts. Besides, the kinetics results indicate that the a-MoS2+x manifests good charge transfer and diffusion kinetics, and its entire charge storage is a combination of surface-controlled capacitance behavior and diffusion-controlled battery behavior. Moreover, some ex-situ Raman, XPS and HRTEM characterization techniques are employed to disclose the Mg2+ storage mechanism. Such remarkable magnesium storage properties of a-MoS2+x demonstrates its promising application as cathode for magnesium ion batteries.

Enhancing Europium Adsorption Effect of Fe on Several Geological Materials by Applying XANES, EXAFS, and Wavelet Transform Techniques.

This study conducted adsorption experiments using Europium (Eu(III)) on geological materials collected from Taiwan. Batch tests on argillite, basalt, granite, and biotite showed that argillite and basalt exhibited strong adsorption reactions with Eu. X-ray diffraction (XRD) analysis also clearly indicated differences before and after adsorption. By combining X-ray absorption near-edge structure (XANES), extended X-ray absorption fine structure (EXAFS), and wavelet transform (WT) analyses, we observed that the Fe2O3 content significantly affects the Eu-Fe distance in the inner-sphere layer during the Eu adsorption process. The wavelet transform analysis for two-dimensional information helps differentiate two distances of Eu-O, which are difficult to analyze, with hydrated outer-sphere Eu-O distances ranging from 2.42 to 2.52 Å and inner-sphere Eu-O distances from 2.27 to 2.32 Å. The EXAFS results for Fe2O3 and SiO2 in argillite and basalt reveal different adsorption mechanisms. Fe2O3 exhibits inner-sphere surface complexation in the order of basalt, argillite, and granite, while SiO2 forms outer-sphere ion exchange with basalt and argillite. Wavelet transform analysis also highlights the differences among these materials.

Low-crystalline 1T/2H-MoSe2 heterostructure as the high-rate and ultra-long-lifespan cathode materials for magnesium ion batteries

Two-dimensional layered-like materials are attracted extensive attention to be the potential cathode materials for magnesium ion batteries because of the wide layer distances and high capacities. Whereas such strong interaction between bivalent Mg2+ and layered cathode materials is prone to cause the slow diffusion kinetics, and irreversible electrochemical reaction, finally bringing about the low specific capacity and inferior rate capability. Meanwhile, limited by the inherent crystal structure of MoSe2 and unsuitable electrolyte, the magnesium storage properties are not ideal. Herein, the low-crystalline 1T/2H-MoSe2 heterostructure (LC-MoSe2) is synthesized via one-step hydrothermal method. Such low-crystalline feature of LC-MoSe2 and MgCl+ in the electrolyte significantly decrease the Mg2+ diffusion barrier, and largely promote the Mg2+ diffusion kinetics. The rich heterogeneous interfaces in the 1T/2H-MoSe2 boost the electron/ion transfer kinetics and endow plentiful active sites for the Mg2+ storage. As expected, the LC-MoSe2 exhibits a high discharge capacity (257.4 mAh g−1/0.5 A g−1/200 cycles) and stable long-span cyclic life of 2000/1000 loops even at 2/5 A g−1, distinctly transcending those of relatively high-crystalline MoSe2 (HC-MoSe2). Such electrode can also surprisingly cycle at an ultra-high rate of 10 A g−1. Meanwhile, the charge transfer/ion diffusion kinetics along with charge storage mechanism of LC-MoSe2 are carried out by various kinetics strategies from experimental and theoretical aspects. The reaction mechanism has also been discussed by some ex-situ characterization techniques. The remarkable Mg2+ storage properties of LC-MoSe2 cathode materials provide new ideas for the long-run development of MIBs.

SURFACE ACTIVITY AND PHASE BEHAVIOUR OF POTASSIUM HEPTYLENE DECYL SUCCINATE / WATER BINARY SYSTEM

The surface activity of potassium heptylene decyl succinate (PHDS) at water-air interface was studied. The obtained results showed a very good correlation between the surface activity of PHDS and concentration of surfactant solutions and temperature of the system. The phase behaviour and structure of aggregates in PHDS)/water binary system were investigated. The phase diagram of the PHDS/water binary system was obtained depending on the concentration of components and temperature of the system. It was established that due to the double hydrocarbon chain of the PHDS molecule, the lamellar liquid crystalline phase exists across a wide range of the phase diagram. It was shown that upon the addition of water, the cross-sectional area of the PHDS molecules in lamellar liquid crystals is changed insignificantly. This result was associated with the invariability of the distance of the lipophilic layers of formed lamellar liquid crystals by PHDS molecules. On the basis of video-enhanced microscopic studies, it was established that in two-phase region of the phase diagram, lamellar liquid crystals coexist with water in the form of vesicles.

On the charge transport mechanism and the dielectric behavior of Fe-doped SnO2/rGO heterostructure

Graphene Oxide (GO) was associated to Fe-doped SnO2 nanoparticles (NPs) through a simple elaboration method to obtain Fe-doped SnO2/reduced graphene oxide (rGO) nanostructure. The effect of GO content on the structural, morphology, transport and dielectric properties of the SnO2/rGO nanocomposite was deeply investigated. X-ray diffraction (XRD) patterns depict the obtention of SnO2 rutile structure and revealed an effect of the NPs size the rGO layer to layer distance. However, transmission electron microscopy (TEM) exploration shows the formation of rGO nanospheres co-present with Fe-doped SnO2 NPs. The electrical properties of the obtained structure were examined through impedance analysis. The conductivity of the SnO2:Fe/rGO nanocomposite obviously increases with the GO amount. The analysis of the relaxation phenomenon shows an abrupt decrease of the relaxation time upon GO addition. A charge carriers transfer is suggested to occur between Fe-doped SnO2 NPs and rGO for high graphene oxide concentrations. Hydrogen bonds are suggested to be established between these NPs and rGO. The functional groups at the NPs/rGO interface were found to considerably contribute to the dielectric response of the heterostructure. Dielectric losses were also evaluated and are suggested to be particularly affected by the rGO functional groups. The explored electric and dielectric properties present the SnO2:Fe/rGO heterostructure as a potential candidate for supercapacitor and electrical battery electrodes.

Electrical conductivity of graphene/copper composites at lattice scale

Graphene/copper composites are potential structure-function integrated materials. Different from previous micro-nano scale composites, graphene/copper lattice-scale composites and their effects on electrical conductivity are investigated in this work. Using the first-principles calculation to explore the effects of different numbers of graphene layers on the properties of graphene/copper composites, it is found that with the increase of graphene layer numbers, the interfacial bonding strength improves, but the electrical properties show a decreasing trend due to the electron scattering and increasing Cu–C layer distance. The single-layer graphene/copper composite has the most excellent electrical properties, with the highest density of states at the Fermi level and the most charge transfer. A series of layered-structural composites at lattice scale are screened, and their electrical properties and dynamic stability are also predicted. These composites rely on metallic bonding to connect copper and carbon atoms, most of which show obvious vertical charge transfer and high conductivity, with short Cu–C layer distance and alternating arrangement of metal layers and hexagonal carbon atoms. CuC2 (derived from MgB2) has the highest average conductivity and dynamic stability and can be considered an ideal lattice-scale composite. The development of new lattice-scale composites is significant for the future research of graphene/copper composites.

High-precision, real-time wavefront sensing via sparse diffractive deep neural networks

As a key component of adaptive optics systems, wavefront sensing technology is an important way to effectively obtain aberrant phases in optical systems for high-capacity optical communications and high-quality imaging in relevant applications ranging from biological imaging to astronomical observation. To enhance the time efficiency of detection, the wavefront sensing with diffraction deep neural network (D2NN) directly calculates the wavefront information in the optical field. However, the compactness of the D2NN structure and the accuracy of wavefront prediction are important bottlenecks, restricting its practical application. Here, we design a multi-layer compact D2NN based on Bayesian optimization, called sparse D2NN (SD2NN), to achieve high-precision, real-time direct wavefront sensing. The experimental results demonstrated a reduction in the root-mean-square error (RMSE) of the SD2NN wavefront sensing of approximately 45.4%, along with a reduction in the axial length of approximately 82% in comparison to the unoptimized fully connected D2NN. This resulted in the attainment of a minimum layer distance of 8.77 mm. In addition, we additionally explored the effects of network depth and neuron size on the wavefront sensing performance of SD2NN and further summarized the general law of diffraction layer distance and neuron size. The proposed method will provide a reliable means of designing miniaturized integrated wavefront sensing chips.

Monitoring process stability in robotic wire-laser directed energy deposition based on multi-modal deep learning

Robotized wire-laser directed energy deposition (DED) is a highly anticipated technology with excellent material utilization and deposition efficiency for fabricating complex-structure metal parts. Nevertheless, the immaturity of the monitoring and control techniques for the deposition process stability are the main challenges in achieving automatic and repeatable manufacturing of metal parts. This study proposes a novel approach to monitor the process stability, i.e., the intersection point between the laser beam and the wire to the top layer distance (IPTD), in robotic wire-laser DED based on a designed multi-modal IPTD estimation model and coaxial visual sensing. The novelty is that directly extracting deposition height features from coaxial molten pool images is attempted based on deep learning. In particular, the designed multi-modal IPTD estimation model, consisting of a convolutional neural network (CNN) part and a fully connected network, combines the features of molten pool images and process parameters to estimate the IPTD state. Six model architectures and three image pixel sizes are used in the IPTD classification tasks to determine the CNN part architecture and the input image pixel size of the multi-modal deep learning model based on classification results. The regression performances of established single-modal and multi-modal IPTD estimation models are studied and discussed. Compared to other model architectures, the ResNet-18 model possesses the highest convergence rate during training and the best classification accuracy of 0.9975 on the testing dataset with the image pixel size of 180 × 105. The fitting accuracy and generalization performance of the multi-modal IPTD estimation model are marked superior to the single-modal IPTD estimation model. Validation experiments reveal the effectiveness of the proposed monitoring approach of process stability. This study will lay a solid foundation for the future control of process stability in robotic wire-laser DED.

Enhancing the electromagnetic interference shielding performance of composite paper with corrugated paper-like structure

The structural design of material significantly influences its electromagnetic interference (EMI) shielding performance, providing an intelligent approach to attain desirable EMI shielding performances. Inspired by the ultra-large distance of the middle layer in corrugated paper, we proposed a novel composite paper with corrugated paper-like structure via the assembling of two pieces of surface-modified filter paper and an aerogel film. Specifically, a conventional filter paper was modified with the conductive hydrogel film consisting of TEMPO-oxidized cellulose nanofibers (TOCNF), cationic starch (CS) and Ti3C2Tx. The TOCNF and CS rapidly formed a composite hydrogel when mixed, due to their electrostatic interactions. The aforementioned aerogel film was produced through the freeze-drying of TOCNF/CS hydrogel, and it enlarged the distance between two conductive hydrogel film modified papers when inserted. The assembled composite papers demonstrated a maximum EMI SE of 71.0 dB, improved by 19.7 % as compared to the control without the aerogel film (59.3 dB). The expansion of the distance between conductive layers likely facilitated the enhancement in the multiple reflections and absorptions of electromagnetic waves. This novel composite paper showed better EMI shielding performance than many previously-reported materials considering the thickness and conductive filler dosage. In addition, the composite paper also showed exceptional infrared stealth capabilities since it effectively shielded the thermal radiation from human body. The composite paper still exhibited good infrared stealth ability at high temperature conditions (up to 120 ℃). Therefore, this research could inspire innovative concepts in designing high-performance and multifunctional EMI shielding materials in an economical way.

Sulfur and Wavy-Stacking Boosted Superior Lithium Storage in 2D Covalent Organic Frameworks.

2D conjugated covalent organic frameworks (c-COFs) provide an attractive foundation as organic electrodes in energy storage devices, but their storage capability is long hindered by limited ion accessibility within densely π-π stacked interlayers. Herein, two kinds of 2D c-COFs based on dioxin and dithiine linkages are reported, which exhibit distinct in-plane configurations-fully planar and undulated layers. X-ray diffraction analysis reveals wavy square-planar networks in dithiine-bridged COF (COF-S), attributed to curved C─S─C bonds in the dithiine linkage, whereas dioxin-bridged COF (COF-O) features densely packed fully planar layers. Theoretical and experimental results elucidate that the undulated stacking within COF-S possesses an expanded layer distance of 3.8 Å and facilitates effective and rapid Li+ storage, yielding a superior specific capacity of 1305 mAh g-1 at 0.5 A g-1, surpassing that of COF-O (1180 mAh g-1 at 0.5 A g-1). COF-S also demonstrates an admirable cycle life with 80.4% capacity retention after 5000 cycles. As determined, self-expanded wavy-stacking geometry, S-enriched dithiine in COF-S enhances the accessibility and redox activity of Li storage, allowing each phthalocyanine core to store 12 Li+ compared to 8 Li+ in COF-O. These findings underscore the elements and stacking modes of 2D c-COFs, enabling tunable layer distance and modulation of accessible ions.

Exploiting the waste heat in a proton exchange membrane fuel cell with a capacitive salinity/heat engine

For fully utilizing the low-grade waste heat (LGWH) of the proton exchange membrane fuel cell (PEMFC), a novel coupled system primarily involving a PEMFC and a capacitive salinity/heat engine (CSHE) is proposed. Based on thermodynamic and electrochemical theories, mathematical formulas of the power output, efficiency, and exergy efficiency are deduced accounting for the significant irreversible losses within the coupled system. The superiority is expounded by contrasting the generic performance characteristics of the sub-systems and the coupled system. In addition, numerical results demonstrate that the maximal power output density and its corresponding efficiency and exergy efficiency of the coupled system enhanced by 11.43%, 12.75%, and 9.96%, respectively, over the PEMFC alone under the same operating conditions. Furthermore, the impacts of some parameters, for instance, proton exchange membrane (PEM) thickness, the PEMFC working temperature and working pressure, electric charge density ratio, charging cut-off voltage, and Stern layer distance, on the coupled system performance are meticulously discussed. The results of the study may supply a reference for the design and operation of such a salinity gradient energy recovery system and create a new pathway for recycling LGWH from PEMFC.

Assessing Intra-Bundle Impregnation in Partially Impregnated Glass Fiber-Reinforced Polypropylene Composites Using a 2D Extended-Field and Multimodal Imaging Approach.

This study evaluates multimodal imaging for characterizing microstructures in partially impregnated thermoplastic matrix composites made of woven glass fiber and polypropylene. The research quantifies the impregnation degree of fiber bundles within composite plates manufactured through a simplified compression resin transfer molding process. For comparison, a reference plate was produced using compression molding of film stacks. An original surface polishing procedure was introduced to minimize surface defects while polishing partially impregnated samples. Extended-field 2D imaging techniques, including polarized light, fluorescence, and scanning electron microscopies, were used to generate images of the same microstructure at fiber-scale resolutions throughout the plate. Post-processing workflows at the macro-scale involved stitching, rigid registration, and pixel classification of FM and SEM images. Meso-scale workflows focused on 0°-oriented fiber bundles extracted from extended-field images to conduct quantitative analyses of glass fiber and porosity area fractions. A one-way ANOVA analysis confirmed the reliability of the statistical data within the 95% confidence interval. Porosity quantification based on the conducted multimodal approach indicated the sensitivity of the impregnation degree according to the layer distance from the pool of melted polypropylene in the context of simplified-CRTM. The findings underscore the potential of multimodal imaging for quantitative analysis in composite material production.

State change of Na clusters in hard carbon electrodes and increased capacity for Na-ion batteries achieved by heteroatom doping

Although heteroatom doping is an effective method to improve the capacity of hard carbon (HC) anodes in Na-ion batteries (NIBs), the complicated structure of HC leads to uncertainty when understanding the effects of heteroatom doping on sodium storage. This study shows the effects of phosphorus and sulfur doping to HC on sodium storage using solid-state NMR to improve the capacity of HC prepared by the carbonization of resorcinol formaldehyde (RF) resin at 1100 °C. Heteroatom doping increased the battery capacity of the HC, especially the plateau capacity, but the interlayer distance of the carbon layers in the HC did not expand considerably. 23Na solid-state NMR revealed that heteroatom doping facilitates the formation of quasi-metallic sodium clusters, thereby contributing to the plateau capacity increase. The metallicity of the sodium clusters in heteroatom-doped HC samples was controlled by the amount of doped-phosphorous. XPS and 31P NMR detected various phosphorus sites such as phosphine and phosphine oxide in the carbon structure.

Research on Gas Control Technology in Goaf Based on the Influence of Mining Speed

To comprehensively understand the influence of mining speed on gas emissions in goaf during coal seam extraction, enhance gas extraction efficiency in goaf, manage gas emissions at the working face, and ensure safety in the mining production process. This study focuses on the No. 3 mining area of Wangjialing Mine, employing numerical simulations to analyze the evolution of mining-induced fractures and the characteristics of gas distribution in the overburden at varying mining speeds. Furthermore, by integrating actual gas emission and extraction data at the production face, this study examines the quantitative relationship between mining speed and gas emissions in the goaf, identifying optimal regions for high-position borehole layouts and conducting borehole optimization design and investigation. The results of this study indicate that the initial caving step distance of the goaf roof increases with the advancement speed of the working face. Conversely, the maximum height of through fractures in the overburden decreases as the mining speed increases, while delamination fractures are minimally affected by the advancement speed. By categorizing and averaging data on goaf mining speed, the impact of initial and periodic pressure on gas emissions can be effectively mitigated, revealing a linear correlation coefficient of 0.94 between goaf gas emissions and mining speed. At varying mining speeds of the working face, the efficient extraction layer and horizontal distance parameters of gas extraction boreholes in the goaf conform to the linear equation y = ax ± b. Based on the research findings, an optimization design for mining face speed and high-level borehole parameters in the goaf was implemented. The average gas extraction rate of high-level directional boreholes reached 68% throughout the extraction period. Gas emissions at the working face were effectively controlled below 10 m3/min, with the maximum gas concentration at the upper corners and return airflow kept below 0.8%. This effectively managed gas emissions at the working face, ensuring safe production in the mine, providing a theoretical basis for identifying gas-rich areas in the mining-induced overburden, and enhancing gas extraction efficiency at the working face.

Bond-Engineered MoSe2 Nanosheets with Expanded Layers and an Enriched 1T Phase for Highly Efficient Na+ Storage.

MoSe2 has attracted significant interest for Na+ storage due to its large interlayer distance, favorable band gap structure, and satisfying theoretical specific capacity. Nevertheless, the poor conductivity and large volume stress/strain always lead to poor cycle stability and limited rate capability. Herein, the P-Se bond and phase engineering strategies are proposed to enhance the stability of MoSe2 with the assistance of carbon compositing. Systematical characterizations confirm that the presence of a strong P-Se bond can ensure the good structural stability and enlarge the layer distance of the MoSe2 anode. 1T phase-enriched composition endows excellent conductivity and thus fast Na+ transport kinetics. Additionally, the combination of carbon contributes to the improvement of electron conductivity, further enhancing the reversible Na+ storage and cyclic stability. Consequently, an ultrastable reversible specific capacity of 347.8 mAh g-1 with a high retention ratio of 99.1% can be maintained after 1000 cycles at 1 A g-1, which is superior to the previous reports of MoSe2 nanosheets. The presented strategy is ingenious, offering an effective guidance to designing advanced electrodes to be applied in rechargeable batteries with a long lifespan.

Exploring threshold of Al-impurities towards high-performance Al-doped Regenerated LiCoO2

Direct regeneration, as the main recycling manner, displays the short-process and high economic value, which has been devoted to considerable attentions. Limited by the existed pre-treatments, there are still some Al-impurities of spent material, resulting in the unstable electrochemical properties of regenerated material, meanwhile the excessive removal of Al-impurities brings the risk of regeneration cost. Thus, exploring the threshold reference of Al-impurities is urgent for regeneration of spent materials. Herein, through the introduction of Al2O3 with different content, spent LiCoO2 were successfully regenerated, displaying the evolution of physical-chemical properties. With suitable Al adding (0.02 wt.%), the broadening layer distance and storage space are found. As a cathode, the as-optimized sample shows a capacity of 172.7 mAh g−1 at 0.2 C, and the capacity retention was 84 % after 500 cycles at 5.0 C, even better than Al-impurity-free regenerated sample. Supported by the detailed kinetic analysis, it could be deduced that, suitable Al-introduction is beneficial for the fast insertion/extraction of ions, meanwhile too excess adding could bring about the blocking of diffusion paths and by-production surface stacking. Given this, this work is expected to shed light on the physical-chemical effect of Al-impurities, meanwhile offering the threshold reference for Al-doping content in practical regenerated industry.

Sedimentary characteristics and model of Cambrian storm in Xuzhou area

The storm deposition types within the Dabeiwang area of Xuzhou City, Jiangsu Province, China, showcase a wide range of diversity and distinctly apparent characteristics. Based on measured sections and thin-section observations, we have studied the typical characteristics of storm deposition in this area, divided the sedimentary sequence, and summarized a comprehensive model of storm deposition. Various rock types such as thick-bedded dolomitic limestone, oolitic limestone, and calcirudite are developed in the study area. The calcirudite exhibits bamboo leaf-like morphology and various distribution forms. Typical storm sedimentary structures such as scour surfaces and mound cross-bedding were identified in the study area. Based on the distance of the gravel layer from the storm center and the depositional environment, the storm sedimentary sequence in the study area can be divided into allopatric-proximal-lagoon facies storm deposit, allopatric-distal-oolitic shoal facies storm deposit, autochthonous-supratidal facies storm deposit, allopatric-distal-interbeach marine storm deposit, sub-allopatric-tide zone facies storm deposit, and autochthonous-tide zone facies storm deposit. We summarize the comprehensive model of Cambrian storm deposition in the Dabeiwang area of Xuzhou, which has enriched the research results of Cambrian storm deposition in Xuzhou and provides support for the construction of a lithofacies paleogeographic pattern.