Lithium sulfur batteries have attracted much attention due to their high theoretical specific energy and environmental friendliness.However,the practical application is severely plagued by the cycling life issues resu...Lithium sulfur batteries have attracted much attention due to their high theoretical specific energy and environmental friendliness.However,the practical application is severely plagued by the cycling life issues resulting from the uncontrollable generation and growth of Li dendrites.Herein,an innovative 3D flexible self-supporting Li anode protection layer of P-Mn_(3)O_(4-x)is constructed via a facile solvothermal method followed by an annealing process.Benefiting from the rich oxygen vacancies coupled with the 3D flexible self-supporting skeleton,abundant lithiophilic sites and high ionic conductivity are obtained,which succeed in guiding Li+homogeneous adsorption and redistribution,accelerating Li+diffusion rate,inducing Li+uniform deposition and nucleation.DFT calculations and experimental results conclusively demonstrate such a protection mechanism.Meanwhile,the effective anchoring and catalytic nature of polar P-Mn_(3)O_(4-x)can also be applied as an immobilization-diffusion-conversion host to improve polysulfides redox.Taking advantage of these merits,super-stable functions for Li symmetric cell matched with P-Mn_(3)O_(4-x)layer are achieved,which exhibits an ultralong lifespan of>5000 h with an ultralow overpotential of 20 m V,far lower than that of bare Li symmetric cell(overpotential of 800 m V only after 250 h)at high current densities of 5 m A cm^(-2)and high plating/stripping capacity of 10 m A h cm^(-2).Even in Li|P-Mn_(3)O_(4-x)||S full cell at 1 C,a high initial discharge specific capacity of 843.1 m A h g^(-1)is still delivered with ultralow capacity fading rate of 0.07%per cycle after 250 cycles,further confirming the synergistic regulation of P-Mn_(3)O_(4-x)for Li nucleation behavior.This work illustrates a sufficient guarantee of 3D protection layer coupled with oxygen vacancies in guiding Li diffusion and nucleation behavior and provides new guidance for promoting the development of advanced Li-S batteries.展开更多
We have realized robust quantum anomalous Hall samples by protecting Cr-doped（Bi,Sb）2Te3 topological insulator films with a combination of LiF and A1Ox capping layers.The AlOx/LiF composite capping layer well keeps ...We have realized robust quantum anomalous Hall samples by protecting Cr-doped（Bi,Sb）2Te3 topological insulator films with a combination of LiF and A1Ox capping layers.The AlOx/LiF composite capping layer well keeps the quantum anomalous Hall states of Cr-doped（Bi,Sb）2Te3 films and effectively prevent them from degradation induced by ambient conditions.The progress is a key step towards the realization of the quantum phenomena in heterostructures and devices based on quantum anomalous Hall system.展开更多
The thermodynamic instability of zinc anodes in aqueous electrolytes leads to issues such as corrosion,hydrogen evolution reactions(HER), and dendrite growth, severely hindering the practical application of zinc-based...The thermodynamic instability of zinc anodes in aqueous electrolytes leads to issues such as corrosion,hydrogen evolution reactions(HER), and dendrite growth, severely hindering the practical application of zinc-based aqueous energy storage devices. To address these challenges, this work proposes a dualfunction zinc anode protective layer, composed of Zn-Al-In layered double oxides(ILDO) by rationally designing Zn-Al layered double hydroxides(Zn-Al LDHs) for the first time. Differing from previous works on the LDHs coatings, firstly, the ILDO layer accelerates zinc-ion desolvation and also captures and anchors SO_(4)^(2-). Secondly, the in-situ formation of the Zn-In alloy phase effectively lowers the nucleation energy barrier, thereby regulating zinc nucleation. Consequently, the zinc anode with the ILDO protective layer demonstrates long-term stability exceeding 1900 h and low voltage hysteresis of 7.5 m V at 0.5 m A cm^(-2) and 0.5 m A h cm^(-2). Additionally, it significantly enhances the rate capability and cycling performance of Zn@ILDO//MnO_(2) full batteries and Zn@ILDO//activated carbon zinc-ion hybrid capacitors.This simple and effective dual-function protective layer strategy offers a promising approach for achieving high-performance zinc-ion batteries.展开更多
Over the years,zinc-ion batteries(ZIBs)have attracted attention as a promising next-generation energy storage technology because of their excellent safety,long cycling performance,eco-friendliness,and high-power densi...Over the years,zinc-ion batteries(ZIBs)have attracted attention as a promising next-generation energy storage technology because of their excellent safety,long cycling performance,eco-friendliness,and high-power density.However,issues,such as the corrosion and dissolution of the Zn anode,limited wet-tability,and lack of sufficient nucleation sites for Zn plating,have limited their practical application.The introduction of a protective layer comprising of tellurium(Te)nanobelts onto the surface of Zn anode has emerged as a promising approach to overcome these limitations and improve the electrochemical behav-ior by enhancing the safety and wettability of ZIBs,as well as providing numerous nucleation sites for Zn plating.In the presence of a Te-based protective layer,the energy power density of the surface-engineered Zn anode improved significantly(ranging from 310 to 144 W h kg^(-1),over a power density range of 270 to 1,800 W kg^(-1)),and the lifespan capability was extended.These results demonstrate that the proposed strategy of employing Te nanobelts as a protective layer holds great promise for enhancing the energy storage performance of zIBs,making them even more attractive as a viable energy storage solution forthefuture.展开更多
Aqueous zinc-ion batteries possess substantial potential for energy storage applications;however,they are hampered by challenges such as dendrite formation and uncontrolled side reactions occurring at the zinc anode.I...Aqueous zinc-ion batteries possess substantial potential for energy storage applications;however,they are hampered by challenges such as dendrite formation and uncontrolled side reactions occurring at the zinc anode.In our investigation,we sought to mitigate these issues through the utilization of in situ zinc complex formation reactions to engineer hydrophobic protective layers on the zinc anode surface.These robust interfacial layers serve as effective barriers,isolating the zinc anode from the electrolyte and active water molecules and thereby preventing hydrogen evolution and the generation of undesirable byproducts.Additionally,the presence of numerous zincophilic sites within these protective layers facilitates uniform zinc deposition while concurrently inhibiting dendrite growth.Through comprehensive evaluation of functional anodes featuring diverse functional groups and alkyl chain lengths,we meticulously scrutinized the underlying mechanisms influencing performance variations.This analysis involved precise modulation of interfacial hydrophobicity,rapid Zn^(2+)ion transport,and ordered deposition of Zn^(2+)ions.Notably,the optimized anode,fabricated with octadecylphosphate(OPA),demonstrated exceptional performance characteristics.The Zn//Zn symmetric cell exhibited remarkable longevity,exceeding 4000 h under a current density of 2 mA cm^(-2)and a capacity density of 2 mA h cm^(-2),Furthermore,when integrated with a VOH cathode,the complete cell exhibited superior capacity retention compared to anodes modified with alternative organic molecules.展开更多
Cake layer formation is inevitable over time for ultrafiltration(UF)membrane-based drinking water treatment.Although the cake layer is always considered to cause membrane fouling,it can also act as a"dynamic prot...Cake layer formation is inevitable over time for ultrafiltration(UF)membrane-based drinking water treatment.Although the cake layer is always considered to cause membrane fouling,it can also act as a"dynamic protection layer",as it further adsorbs pollutants and dramatically reduces their chance of getting to the membrane surface.Here,the UF membrane fouling performance was investigated with pre-deposited loose flocs in the presence of humic acid(HA).The results showed that the floc dynamic protection layer played an important role in removing HA.The higher the solution pH,the more negative the floc charge,resulting in lower HA removal efficiency due to the electrostatic repulsion and large pore size of the floc layer.With decreasing solution pH,a positively charged floc dynamic protection layer was formed,and more HA molecules were adsorbed.The potential reasons were ascribed to the smaller floc size,greater positive charge,and higher roughness of the floc layer.However,similar membrane fouling performance was also observed for the negative and positive floc dynamic protection layers due to their strong looseness characteristics.In addition,the molecular weight(MW)distribution of HA also played an important role in UF membrane fouling behavior.For the small MW HA molecules,the chance of forming a loose cake layer was high with a negatively charged floc dynamic protection layer,while for the large MW HA molecules it was high with a positively charged floc dynamic protection layer.As a result,slight UF membrane fouling was induced.展开更多
ZrCoCe getter films with thickness of ~2.3 lm were deposited on Si(100) wafers by direct current(DC)magnetron sputtering process. A 400-nm-thick Pd protection layer was then deposited on the as-deposited ZrCoCe film w...ZrCoCe getter films with thickness of ~2.3 lm were deposited on Si(100) wafers by direct current(DC)magnetron sputtering process. A 400-nm-thick Pd protection layer was then deposited on the as-deposited ZrCoCe film without exposure to atmosphere. Microstructure, surface morphology and surface chemical state of the films were analyzed. Moreover, hydrogen sorption properties were determined. The results show that the ZrCoCe film displays a cauliflower-like morphology and a porous columnar-like structure which is composed of nanocrystal grains. The Pd protection layer tightly adheres to the surface of the ZrCoCe film and efficiently prevents the oxidation of Zr under exposure to atmosphere. We find that the hydrogen sorption properties of the Pd-ZrCoCe film are significantly improved,in comparison with those of the as-deposited ZrCoCe film.展开更多
Aiming at the limitation of the traditional method for determination of protection region, combined with the actual situation of a mine, a new method for determination of protection region was put forward （including ...Aiming at the limitation of the traditional method for determination of protection region, combined with the actual situation of a mine, a new method for determination of protection region was put forward （including the protection of working face layout and development direction）, that is, gas flow observation analysis on the spot and gas content contrast method. The protection region was determined by gas flow observation analysis, gas content contrast, and computer numerical simulation combined with engineering practice. In the process of gas content test, the fixed sampling method ＂big hole drill reaming, small orifice drill rod connected with core tube＂ was employed. The results show that the determined protection region is in accordance with the actual site situation. The fixed sampling method ensures the accuracy of gas measurement of gas content.展开更多
The concentration difference in the near-surface region of lithium metal is the main cause of lithium dendrite growth.Resolving this issue will be key to achieving high-performance lithium metal batteries(LMBs).Herein...The concentration difference in the near-surface region of lithium metal is the main cause of lithium dendrite growth.Resolving this issue will be key to achieving high-performance lithium metal batteries(LMBs).Herein,we construct a lithium nitrate(LiNO_(3))-implanted electroactiveβphase polyvinylidene fluoride-co-hexafluoropropylene(PVDF-HFP)crystalline polymorph layer(PHL).The electronegatively charged polymer chains attain lithium ions on the surface to form lithium-ion charged channels.These channels act as reservoirs to sustainably release Li ions to recompense the ionic flux of electrolytes,decreasing the growth of lithium dendrites.The stretched molecular channels can also accelerate the transport of Li ions.The combined effects enable a high Coulombic efficiency of 97.0%for 250 cycles in lithium(Li)||copper(Cu)cell and a stable symmetric plating/stripping behavior over 2000 h at 3 mA cm^(-2)with ultrahigh Li utilization of 50%.Furthermore,the full cell coupled with PHL-Cu@Li anode and Li Fe PO_(4) cathode exhibits long-term cycle stability with high-capacity retention of 95.9%after 900 cycles.Impressively,the full cell paired with LiNi_(0.87)Co_(0.1)Mn_(0.03)O_(2)maintains a discharge capacity of 170.0 mAh g^(-1)with a capacity retention of 84.3%after 100 cycles even under harsh condition of ultralow N/P ratio of 0.83.This facile strategy will widen the potential application of LiNO_(3)in ester-based electrolyte for practical high-voltage LMBs.展开更多
The differential cubature solution to the problem of a Mindlin plate lying on the Winkler foundation with two simply supported edges and two clamped edges was derived.Discrete numerical technology and shape functions ...The differential cubature solution to the problem of a Mindlin plate lying on the Winkler foundation with two simply supported edges and two clamped edges was derived.Discrete numerical technology and shape functions were used to ensure that the solution is suitable to irregular shaped plates.Then,the mechanical model and the solution were employed to model the protection layer that isolates the mining stopes from sea water in Sanshandao gold mine,which is the first subsea mine of China.Furthermore,thickness optimizations for the protection layers above each stope were conducted based on the maximum principle stress criterion,and the linear relations between the best protection layer thickness and the stope area under different safety factors were regressed to guide the isolation design.The method presented in this work provides a practical way to quickly design the isolation layer thickness in subsea mining.展开更多
With the large-scale service of lithium-ion batteries(LIBs),their failures have attracted significant attentions.While the decay of active materials is the primary cause for LIB failures,the degradation of auxiliary m...With the large-scale service of lithium-ion batteries(LIBs),their failures have attracted significant attentions.While the decay of active materials is the primary cause for LIB failures,the degradation of auxiliary materials,such as current collector corrosion,should not be disregarded.Therefore,it is necessary to conduct a comprehensive review in this field.In this review,from the perspectives of electrochemistry and materials,we systematically summarize the corrosion behavior of aluminum cathode current collector and propose corresponding countermeasures.Firstly,the corrosion type is clarified based on the properties of passivation layers in different organic electrolyte components.Furthermore,a thoroughgoing analysis is presented to examine the impact of various factors on aluminum corrosion,including lithium salts,organic solvents,water impurities,and operating conditions.Subsequently,strategies for electrolyte and protection layer employed to suppress corrosion are discussed in detail.Lastly and most importantly,we provide insights and recommendations to prevent corrosion of current collectors,facilitate the development of advanced current collectors and the implementation of next-generation high-voltage stable LIBs.展开更多
Accurate simulation of the cracking process caused by rust expansion of reinforced concrete(RC)structures plays an intuitive role in revealing the corrosion-induced failure mechanism.Considering the quasi-brittle frac...Accurate simulation of the cracking process caused by rust expansion of reinforced concrete(RC)structures plays an intuitive role in revealing the corrosion-induced failure mechanism.Considering the quasi-brittle fracture of concrete,the fracture phase field driven by the compressive-shear term is constructed and added to the traditional brittle fracture phase field model.The rationality of the proposed model is verified by a mixed fracture example under a shear displacement load.Then,the extended fracture phase model is applied to simulate the corrosion-induced cracking process of RC.The cracking patterns caused by non-uniform corrosion expansion are discussed for RC specimens with homogeneous macroscopically or heterogeneous with different polygonal aggregate distributions at the mesoscopic scale.Then,the effects of the protective layer on the crack propagation trajectory and cracking resistance are investigated,illustrating that the cracking angle and cracking resistance increase with the increase of the protective layer thickness,consistent with the experimental observation.Finally,the corrosion-induced cracking process of concrete specimens with large and small spacing rebars is simulated,and the interaction of multiple corrosion cracking is easily influenced by the reinforcement spacing,which increases with the decrease of the steel bar interval.These conclusions play an important role in the design of engineering anti-corrosion measures.The fracture phase field model can provide strong support for the life assessment of RC structures.展开更多
A variety of techniques, such as chemical analysis, scanning electron microscopy-energy dispersive spectroscopy, and X-ray diffraction, were applied to characterize the adhesion protective layer formed below the blast...A variety of techniques, such as chemical analysis, scanning electron microscopy-energy dispersive spectroscopy, and X-ray diffraction, were applied to characterize the adhesion protective layer formed below the blast furnace taphole level when a certain amount of titanium-bearing burden was used. Samples of the protective layer were extracted to identify the chemical composition, phase assemblage, andistribution. Furthermore, the formation mechanism of the protective layer was determined after clarifying the source of each componenFinally, a technical strategy was proposed for achieving a stable protective layer in the hearth. The results show that the protective layemainly exists in a bilayer form in the sidewall, namely, a titanium-bearing layer and a graphite layer. Both the layers contain the slag phaswhose major crystalline phase is magnesium melilite（Ca2Mg Si2O7） and the main source of the slag phase is coke ash. It is clearly determinethat solid particles such as graphite, Ti（C,N） and Mg Al2O4play an important role in the formation of the protective layer, and the key factofor promoting the formation of a stable protective layer is reasonable control of the evolution behavior of coke.展开更多
A long campaign life of blast furnaces is heavily linked to the existence of a protective layer in their hearths. In this work, we conducted dissection studies and investigated damage in blast furnace hearths to estim...A long campaign life of blast furnaces is heavily linked to the existence of a protective layer in their hearths. In this work, we conducted dissection studies and investigated damage in blast furnace hearths to estimate the formation mechanism of the protective layer. The results illustrate that a significant amount of graphite phase was trapped within the hearth protective layer. Furthermore, on the basis of the thermodynamic and kinetic calculations of the graphite precipitation process, a precipitation potential index related to the formation of the graphite-rich protective layer was proposed to characterize the formation ability of this layer. We determined that, under normal operating conditions, the precipitation of graphite phase ~om hot metal was thermodynamically possible. Among elements that exist in hot metal, C, Si, and P favor graphite precipitation, whereas Mn and Cr inhibit this process. Moreover, at the same hot-face temperature, an increase of carbon concentration in hot metal can shorten the precipitation time. Finally, the results suggest that measures such as reducing the hot-face tem- perature and increasing the degree of carbon saturation in hot metal are critically important to improve the precipitation potential index.展开更多
Lithium(Li)metal anodes with the high theoretical specific capacity(3860 mAh g^(-1))and most negative reduction potential(-3.04 V vs.standard hydrogen electrode)have been considered as an ultimate choice for energy st...Lithium(Li)metal anodes with the high theoretical specific capacity(3860 mAh g^(-1))and most negative reduction potential(-3.04 V vs.standard hydrogen electrode)have been considered as an ultimate choice for energy storage devices with high energy density[1-4].However,the practical applications of Li metalbased batteries(LMBs)are confronted with two tough issues:Li dendrite growth induced by uneven Li depositions and unstable solid electrolyte interphase(SEI)(Fig.1a)[5,6].展开更多
The intrinsically safe Zn||I_(2) battery,one of the leading candidates aiming to replace traditional Pb-acid batteries,is still seriously suffering from short shelf and cycling lifespan,due to the uncontrolled I_(3)^(...The intrinsically safe Zn||I_(2) battery,one of the leading candidates aiming to replace traditional Pb-acid batteries,is still seriously suffering from short shelf and cycling lifespan,due to the uncontrolled I_(3)^(−)-shuttling and dynamic parasitic reactions on Zn anodes.Considering the fact that almost all these detrimental processes terminate on the surfaces of Zn anodes,modifying Zn anodes’surface with protecting layers should be one of the most straightforward and thorough approaches to restrain these processes.Herein,a facile zeolite-based cation-exchange protecting layer is designed to comprehensively suppress the unfavored parasitic reactions on the Zn anodes.The negatively-charged cavities in the zeolite lattice provide highly accessible migration channels for Zn^(2+),while blocking anions and electrolyte from passing through.This low-cost cation-exchange protecting layer can simultaneously suppress self-discharge,anode corrosion/passivation,and Zn dendrite growth,awarding the Zn||I_(2) batteries with ultra-long cycle life(91.92%capacity retention after 5600 cycles at 2 A g^(−1)),high coulombic efficiencies(99.76%in average)and large capacity(203–196 mAh g^(−1) at 0.2 A g^(−1)).This work provides a highly affordable approach for the construction of high-performance Zn-I_(2) aqueous batteries.展开更多
Silicon(Si)has been attracting extensive attention for rechargeable lithium(Li)‐ion batteries due to its high theoretical capacity and low potential vs Li/Li+.However,it remains challenging and problematic to stabili...Silicon(Si)has been attracting extensive attention for rechargeable lithium(Li)‐ion batteries due to its high theoretical capacity and low potential vs Li/Li+.However,it remains challenging and problematic to stabilize the Si materials during electrochemical cycling because of the huge volume expansion,which results in losing electric contact and pulverization of Si particles.Consequently,the Si anode materials generally suffer from poor cycling,poor rate performance,and low coulomb efficiency,preventing them from practical applications.Up‐to‐date,there are numerous reports on the engineering of Si anode materials at microscale and nanoscale with significantly improved electrochemical performances.In this review,we will concentrate on various precisely designed protective layers for silicon‐based materials,including carbon layers,inorganic layers,and conductive polymer protective layer.First,we briefly introduced the alloying and failure mechanism of Si as anode materials upon electrochemical reactions.Following that,representative cases have been introduced and summarized to illustrate the purpose and advancement of protective coating layers,for instance,to alleviate pulverization and improve conductivity caused by volume expansion of Si particles during charge/discharge process,and maintain the surface stability of Si particles to form a stable solid‐electrolyte interphase layer.At last,possible strategies on the protective coating layer for stabilizing silicon anode materials that can be applied in the future have been indicated.展开更多
In order to solve coal and gas outbursts during mining coal seam,studying on related problems were carried out. According to the theories of mining upper protective layer,proper mining plan were designed and performed...In order to solve coal and gas outbursts during mining coal seam,studying on related problems were carried out. According to the theories of mining upper protective layer,proper mining plan were designed and performed through field experiment. By means of examining several parameters obtained from the field experiment,the protective effects were evaluated and the protective scope and related parameters were determined. The results of field experiment show that the danger of outbursts was evidently eliminated and the method of mining protective layers is effective and the safety and economic benefits are remarkable. The research has really applied worth and will give beneficial references to mining area with analogous conditions.展开更多
Based on the occurrence features of Group B coal-seams at a coal mine in the Huainan coal mining area, the elasto-plastic mechanical damage constitutive functions and numerical model for the protective layer excavatio...Based on the occurrence features of Group B coal-seams at a coal mine in the Huainan coal mining area, the elasto-plastic mechanical damage constitutive functions and numerical model for the protective layer excavation were established. With the UDEC2D computer program, after the upper protective layer was mined, the stress field change trends, crack development, and expansion deformation trends of underlying coal rock seams in the floor of the working face were simulated and analyzed. The simulation results show the stress changes in coal rock seams, the evolution process of pre-cracks during the process of upper protective layer mining, the caved zone and fractured zone of the underlying coal rock seams. At the same time, the results from the actual investigation and analysis of protected layer deformation match the simulation values, which verifies the validity and accuracy of numerical simulation results. The study results have an important guiding significance for gas management in low permeability and high gas coal seams with similar mining conditions.展开更多
In order to understand the effect of mining height and floor lithology at the upper protective layer face on the pressure relief of protected coal seams, this paper uses a numerical simulation method to model the pres...In order to understand the effect of mining height and floor lithology at the upper protective layer face on the pressure relief of protected coal seams, this paper uses a numerical simulation method to model the pressure changes at protected coal seam during mining upper protective layer. The results show that the taller the mining height at the upper protective layer face, the greater the protection on protected coal seam due to the higher level of pressure release; the upper protective layer face with hard rock floor impedes the pressure release at the protected coal seam, which affects the overall effect of the pressure release at protected coal seam using the protective layer mining method.展开更多
基金supported by the Natural Science Foundation of Shandong Province(ZR2021MB101,ZR2021ME113,ZR2021ME177,and ZR2021QE096)。
文摘Lithium sulfur batteries have attracted much attention due to their high theoretical specific energy and environmental friendliness.However,the practical application is severely plagued by the cycling life issues resulting from the uncontrollable generation and growth of Li dendrites.Herein,an innovative 3D flexible self-supporting Li anode protection layer of P-Mn_(3)O_(4-x)is constructed via a facile solvothermal method followed by an annealing process.Benefiting from the rich oxygen vacancies coupled with the 3D flexible self-supporting skeleton,abundant lithiophilic sites and high ionic conductivity are obtained,which succeed in guiding Li+homogeneous adsorption and redistribution,accelerating Li+diffusion rate,inducing Li+uniform deposition and nucleation.DFT calculations and experimental results conclusively demonstrate such a protection mechanism.Meanwhile,the effective anchoring and catalytic nature of polar P-Mn_(3)O_(4-x)can also be applied as an immobilization-diffusion-conversion host to improve polysulfides redox.Taking advantage of these merits,super-stable functions for Li symmetric cell matched with P-Mn_(3)O_(4-x)layer are achieved,which exhibits an ultralong lifespan of>5000 h with an ultralow overpotential of 20 m V,far lower than that of bare Li symmetric cell(overpotential of 800 m V only after 250 h)at high current densities of 5 m A cm^(-2)and high plating/stripping capacity of 10 m A h cm^(-2).Even in Li|P-Mn_(3)O_(4-x)||S full cell at 1 C,a high initial discharge specific capacity of 843.1 m A h g^(-1)is still delivered with ultralow capacity fading rate of 0.07%per cycle after 250 cycles,further confirming the synergistic regulation of P-Mn_(3)O_(4-x)for Li nucleation behavior.This work illustrates a sufficient guarantee of 3D protection layer coupled with oxygen vacancies in guiding Li diffusion and nucleation behavior and provides new guidance for promoting the development of advanced Li-S batteries.
基金supported by the National Natural Science Foundation of China(Grant No.11325421)
文摘We have realized robust quantum anomalous Hall samples by protecting Cr-doped（Bi,Sb）2Te3 topological insulator films with a combination of LiF and A1Ox capping layers.The AlOx/LiF composite capping layer well keeps the quantum anomalous Hall states of Cr-doped（Bi,Sb）2Te3 films and effectively prevent them from degradation induced by ambient conditions.The progress is a key step towards the realization of the quantum phenomena in heterostructures and devices based on quantum anomalous Hall system.
基金Natural Science Foundation of Hunan Province (No.2020JJ4734)High Performance Computing Center of Central South University。
文摘The thermodynamic instability of zinc anodes in aqueous electrolytes leads to issues such as corrosion,hydrogen evolution reactions(HER), and dendrite growth, severely hindering the practical application of zinc-based aqueous energy storage devices. To address these challenges, this work proposes a dualfunction zinc anode protective layer, composed of Zn-Al-In layered double oxides(ILDO) by rationally designing Zn-Al layered double hydroxides(Zn-Al LDHs) for the first time. Differing from previous works on the LDHs coatings, firstly, the ILDO layer accelerates zinc-ion desolvation and also captures and anchors SO_(4)^(2-). Secondly, the in-situ formation of the Zn-In alloy phase effectively lowers the nucleation energy barrier, thereby regulating zinc nucleation. Consequently, the zinc anode with the ILDO protective layer demonstrates long-term stability exceeding 1900 h and low voltage hysteresis of 7.5 m V at 0.5 m A cm^(-2) and 0.5 m A h cm^(-2). Additionally, it significantly enhances the rate capability and cycling performance of Zn@ILDO//MnO_(2) full batteries and Zn@ILDO//activated carbon zinc-ion hybrid capacitors.This simple and effective dual-function protective layer strategy offers a promising approach for achieving high-performance zinc-ion batteries.
基金supported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)grant funded by the Korea government(MOTIE)(RS-2023-00303581,Multiscale Simulation-Driven Development of Cost-Effective and Stable Aqueous Zn Ion Battery with Energy Density of 110 Wh/L for Energy Storage Systems:A Korea-USA Collaboration)。
文摘Over the years,zinc-ion batteries(ZIBs)have attracted attention as a promising next-generation energy storage technology because of their excellent safety,long cycling performance,eco-friendliness,and high-power density.However,issues,such as the corrosion and dissolution of the Zn anode,limited wet-tability,and lack of sufficient nucleation sites for Zn plating,have limited their practical application.The introduction of a protective layer comprising of tellurium(Te)nanobelts onto the surface of Zn anode has emerged as a promising approach to overcome these limitations and improve the electrochemical behav-ior by enhancing the safety and wettability of ZIBs,as well as providing numerous nucleation sites for Zn plating.In the presence of a Te-based protective layer,the energy power density of the surface-engineered Zn anode improved significantly(ranging from 310 to 144 W h kg^(-1),over a power density range of 270 to 1,800 W kg^(-1)),and the lifespan capability was extended.These results demonstrate that the proposed strategy of employing Te nanobelts as a protective layer holds great promise for enhancing the energy storage performance of zIBs,making them even more attractive as a viable energy storage solution forthefuture.
基金financially supported by the Jiangsu Distinguished Professors Project (No.1711510024)the Funding for Scientific Research Startup of Jiangsu University (No.4111510015,19JDG044)+5 种基金the Jiangsu Provincial Program for High-Level Innovative and Entrepreneurial Talents Introductionthe National Natural Science Foundation of China (No.22008091)the Jiangsu Agriculture Science and Technology Innovation Fund (No.CX (21)1007)the Natural Science Foundation of Guangdong Province (2023A1515010894)the Open Project of Luzhou Key Laboratory of Fine Chemical Application Technology (HYJH-2302-A)the National Institute of Education,Singapore,under its Academic Research Fund (RI 1/21 EAH)。
文摘Aqueous zinc-ion batteries possess substantial potential for energy storage applications;however,they are hampered by challenges such as dendrite formation and uncontrolled side reactions occurring at the zinc anode.In our investigation,we sought to mitigate these issues through the utilization of in situ zinc complex formation reactions to engineer hydrophobic protective layers on the zinc anode surface.These robust interfacial layers serve as effective barriers,isolating the zinc anode from the electrolyte and active water molecules and thereby preventing hydrogen evolution and the generation of undesirable byproducts.Additionally,the presence of numerous zincophilic sites within these protective layers facilitates uniform zinc deposition while concurrently inhibiting dendrite growth.Through comprehensive evaluation of functional anodes featuring diverse functional groups and alkyl chain lengths,we meticulously scrutinized the underlying mechanisms influencing performance variations.This analysis involved precise modulation of interfacial hydrophobicity,rapid Zn^(2+)ion transport,and ordered deposition of Zn^(2+)ions.Notably,the optimized anode,fabricated with octadecylphosphate(OPA),demonstrated exceptional performance characteristics.The Zn//Zn symmetric cell exhibited remarkable longevity,exceeding 4000 h under a current density of 2 mA cm^(-2)and a capacity density of 2 mA h cm^(-2),Furthermore,when integrated with a VOH cathode,the complete cell exhibited superior capacity retention compared to anodes modified with alternative organic molecules.
基金supported by the National Natural Science Foundation for Young Scientists of China(No.51608514)the Funds for International Cooperation and Exchange of the National Natural Science Foundation of China(No.51820105011)+1 种基金the National Key R&D Program of China(No.2016YFC0400802)the Program of the Youth Innovation Promotion Association of Chinese Academy of Sciences
文摘Cake layer formation is inevitable over time for ultrafiltration(UF)membrane-based drinking water treatment.Although the cake layer is always considered to cause membrane fouling,it can also act as a"dynamic protection layer",as it further adsorbs pollutants and dramatically reduces their chance of getting to the membrane surface.Here,the UF membrane fouling performance was investigated with pre-deposited loose flocs in the presence of humic acid(HA).The results showed that the floc dynamic protection layer played an important role in removing HA.The higher the solution pH,the more negative the floc charge,resulting in lower HA removal efficiency due to the electrostatic repulsion and large pore size of the floc layer.With decreasing solution pH,a positively charged floc dynamic protection layer was formed,and more HA molecules were adsorbed.The potential reasons were ascribed to the smaller floc size,greater positive charge,and higher roughness of the floc layer.However,similar membrane fouling performance was also observed for the negative and positive floc dynamic protection layers due to their strong looseness characteristics.In addition,the molecular weight(MW)distribution of HA also played an important role in UF membrane fouling behavior.For the small MW HA molecules,the chance of forming a loose cake layer was high with a negatively charged floc dynamic protection layer,while for the large MW HA molecules it was high with a positively charged floc dynamic protection layer.As a result,slight UF membrane fouling was induced.
基金financially supported by the National Natural Science Foundation of China(No.61874137)。
文摘ZrCoCe getter films with thickness of ~2.3 lm were deposited on Si(100) wafers by direct current(DC)magnetron sputtering process. A 400-nm-thick Pd protection layer was then deposited on the as-deposited ZrCoCe film without exposure to atmosphere. Microstructure, surface morphology and surface chemical state of the films were analyzed. Moreover, hydrogen sorption properties were determined. The results show that the ZrCoCe film displays a cauliflower-like morphology and a porous columnar-like structure which is composed of nanocrystal grains. The Pd protection layer tightly adheres to the surface of the ZrCoCe film and efficiently prevents the oxidation of Zr under exposure to atmosphere. We find that the hydrogen sorption properties of the Pd-ZrCoCe film are significantly improved,in comparison with those of the as-deposited ZrCoCe film.
文摘Aiming at the limitation of the traditional method for determination of protection region, combined with the actual situation of a mine, a new method for determination of protection region was put forward （including the protection of working face layout and development direction）, that is, gas flow observation analysis on the spot and gas content contrast method. The protection region was determined by gas flow observation analysis, gas content contrast, and computer numerical simulation combined with engineering practice. In the process of gas content test, the fixed sampling method ＂big hole drill reaming, small orifice drill rod connected with core tube＂ was employed. The results show that the determined protection region is in accordance with the actual site situation. The fixed sampling method ensures the accuracy of gas measurement of gas content.
基金the financial support from the National Natural Science Foundation of China(Nos.22205191 and 52002346)the Science and Technology Innovation Program of Hunan Province(No.2021RC3109)+1 种基金the Natural Science Foundation of Hunan Province,China(No.2022JJ40446)Guangxi Key Laboratory of Low Carbon Energy Material(No.2020GXKLLCEM01)。
文摘The concentration difference in the near-surface region of lithium metal is the main cause of lithium dendrite growth.Resolving this issue will be key to achieving high-performance lithium metal batteries(LMBs).Herein,we construct a lithium nitrate(LiNO_(3))-implanted electroactiveβphase polyvinylidene fluoride-co-hexafluoropropylene(PVDF-HFP)crystalline polymorph layer(PHL).The electronegatively charged polymer chains attain lithium ions on the surface to form lithium-ion charged channels.These channels act as reservoirs to sustainably release Li ions to recompense the ionic flux of electrolytes,decreasing the growth of lithium dendrites.The stretched molecular channels can also accelerate the transport of Li ions.The combined effects enable a high Coulombic efficiency of 97.0%for 250 cycles in lithium(Li)||copper(Cu)cell and a stable symmetric plating/stripping behavior over 2000 h at 3 mA cm^(-2)with ultrahigh Li utilization of 50%.Furthermore,the full cell coupled with PHL-Cu@Li anode and Li Fe PO_(4) cathode exhibits long-term cycle stability with high-capacity retention of 95.9%after 900 cycles.Impressively,the full cell paired with LiNi_(0.87)Co_(0.1)Mn_(0.03)O_(2)maintains a discharge capacity of 170.0 mAh g^(-1)with a capacity retention of 84.3%after 100 cycles even under harsh condition of ultralow N/P ratio of 0.83.This facile strategy will widen the potential application of LiNO_(3)in ester-based electrolyte for practical high-voltage LMBs.
基金Projects(51504044,51204100)supported by National Natural Science Foundation of ChinaProject(14KF05)supported by the Research Fund of The State Key Laboratory of Coal Resources and Mine Safety,CUMT,China+3 种基金Project(cstc2016jcyj A1861)supported by the Research Fund of Chongqing Basic Science and Cutting-Edge Technology Special Projects,ChinaProject(2015CDJXY)supported by the Fundamental Research Funds for the Central UniversitiesProject supported by the China Postdoctoral Science FoundationProject(2011DA105287-MS201503)supported by the Independent Subject of State Key Laboratory of Coal Mine Disaster Dynamics and Control,China
文摘The differential cubature solution to the problem of a Mindlin plate lying on the Winkler foundation with two simply supported edges and two clamped edges was derived.Discrete numerical technology and shape functions were used to ensure that the solution is suitable to irregular shaped plates.Then,the mechanical model and the solution were employed to model the protection layer that isolates the mining stopes from sea water in Sanshandao gold mine,which is the first subsea mine of China.Furthermore,thickness optimizations for the protection layers above each stope were conducted based on the maximum principle stress criterion,and the linear relations between the best protection layer thickness and the stope area under different safety factors were regressed to guide the isolation design.The method presented in this work provides a practical way to quickly design the isolation layer thickness in subsea mining.
文摘With the large-scale service of lithium-ion batteries(LIBs),their failures have attracted significant attentions.While the decay of active materials is the primary cause for LIB failures,the degradation of auxiliary materials,such as current collector corrosion,should not be disregarded.Therefore,it is necessary to conduct a comprehensive review in this field.In this review,from the perspectives of electrochemistry and materials,we systematically summarize the corrosion behavior of aluminum cathode current collector and propose corresponding countermeasures.Firstly,the corrosion type is clarified based on the properties of passivation layers in different organic electrolyte components.Furthermore,a thoroughgoing analysis is presented to examine the impact of various factors on aluminum corrosion,including lithium salts,organic solvents,water impurities,and operating conditions.Subsequently,strategies for electrolyte and protection layer employed to suppress corrosion are discussed in detail.Lastly and most importantly,we provide insights and recommendations to prevent corrosion of current collectors,facilitate the development of advanced current collectors and the implementation of next-generation high-voltage stable LIBs.
基金the National Natural Science Foundation of China(Qing Zhang,Nos.11932006,U1934206,12172121)the Fundamental Research Funds for the Central Universities(Xin Gu,No.B210201031).
文摘Accurate simulation of the cracking process caused by rust expansion of reinforced concrete(RC)structures plays an intuitive role in revealing the corrosion-induced failure mechanism.Considering the quasi-brittle fracture of concrete,the fracture phase field driven by the compressive-shear term is constructed and added to the traditional brittle fracture phase field model.The rationality of the proposed model is verified by a mixed fracture example under a shear displacement load.Then,the extended fracture phase model is applied to simulate the corrosion-induced cracking process of RC.The cracking patterns caused by non-uniform corrosion expansion are discussed for RC specimens with homogeneous macroscopically or heterogeneous with different polygonal aggregate distributions at the mesoscopic scale.Then,the effects of the protective layer on the crack propagation trajectory and cracking resistance are investigated,illustrating that the cracking angle and cracking resistance increase with the increase of the protective layer thickness,consistent with the experimental observation.Finally,the corrosion-induced cracking process of concrete specimens with large and small spacing rebars is simulated,and the interaction of multiple corrosion cracking is easily influenced by the reinforcement spacing,which increases with the decrease of the steel bar interval.These conclusions play an important role in the design of engineering anti-corrosion measures.The fracture phase field model can provide strong support for the life assessment of RC structures.
基金financially supported by the Natural Science Foundation of China(No.51304014)the Natural Science Foundation of China and Baosteel(No.51134008)the National Basic Research Program of China(No.2012CB720401)
文摘A variety of techniques, such as chemical analysis, scanning electron microscopy-energy dispersive spectroscopy, and X-ray diffraction, were applied to characterize the adhesion protective layer formed below the blast furnace taphole level when a certain amount of titanium-bearing burden was used. Samples of the protective layer were extracted to identify the chemical composition, phase assemblage, andistribution. Furthermore, the formation mechanism of the protective layer was determined after clarifying the source of each componenFinally, a technical strategy was proposed for achieving a stable protective layer in the hearth. The results show that the protective layemainly exists in a bilayer form in the sidewall, namely, a titanium-bearing layer and a graphite layer. Both the layers contain the slag phaswhose major crystalline phase is magnesium melilite（Ca2Mg Si2O7） and the main source of the slag phase is coke ash. It is clearly determinethat solid particles such as graphite, Ti（C,N） and Mg Al2O4play an important role in the formation of the protective layer, and the key factofor promoting the formation of a stable protective layer is reasonable control of the evolution behavior of coke.
基金supported the National Science Foundation for Young Scientists of China (No. 51304014)the Open Foundation of the State Key Laboratory of Advanced Metallurgy (No. 41603007)
文摘A long campaign life of blast furnaces is heavily linked to the existence of a protective layer in their hearths. In this work, we conducted dissection studies and investigated damage in blast furnace hearths to estimate the formation mechanism of the protective layer. The results illustrate that a significant amount of graphite phase was trapped within the hearth protective layer. Furthermore, on the basis of the thermodynamic and kinetic calculations of the graphite precipitation process, a precipitation potential index related to the formation of the graphite-rich protective layer was proposed to characterize the formation ability of this layer. We determined that, under normal operating conditions, the precipitation of graphite phase ~om hot metal was thermodynamically possible. Among elements that exist in hot metal, C, Si, and P favor graphite precipitation, whereas Mn and Cr inhibit this process. Moreover, at the same hot-face temperature, an increase of carbon concentration in hot metal can shorten the precipitation time. Finally, the results suggest that measures such as reducing the hot-face tem- perature and increasing the degree of carbon saturation in hot metal are critically important to improve the precipitation potential index.
基金supported by National Key Research and Development Program,China(2016YFA0202500 and 2016YFA0200102)National Natural Science Foundation of China,China(21805161,21808124,U1932220)Fundamental Research Funds for the Central Universites of Central South University,China(2020zzts471)。
文摘Lithium(Li)metal anodes with the high theoretical specific capacity(3860 mAh g^(-1))and most negative reduction potential(-3.04 V vs.standard hydrogen electrode)have been considered as an ultimate choice for energy storage devices with high energy density[1-4].However,the practical applications of Li metalbased batteries(LMBs)are confronted with two tough issues:Li dendrite growth induced by uneven Li depositions and unstable solid electrolyte interphase(SEI)(Fig.1a)[5,6].
基金The authors thank the National Natural Science Foundation of China(51502194,22133005,21973107,and 22103093)the Natural Science Foundation of Shandong(ZR2020ME024)+2 种基金the Science and Technology Commission of Shanghai Municipality(21ZR1472900)the Key Laboratory for Palygorskite Science and Applied Technology of Jiangsu Province(HPK202103)for financial supportOpen access funding provided by Shanghai Jiao Tong University
文摘The intrinsically safe Zn||I_(2) battery,one of the leading candidates aiming to replace traditional Pb-acid batteries,is still seriously suffering from short shelf and cycling lifespan,due to the uncontrolled I_(3)^(−)-shuttling and dynamic parasitic reactions on Zn anodes.Considering the fact that almost all these detrimental processes terminate on the surfaces of Zn anodes,modifying Zn anodes’surface with protecting layers should be one of the most straightforward and thorough approaches to restrain these processes.Herein,a facile zeolite-based cation-exchange protecting layer is designed to comprehensively suppress the unfavored parasitic reactions on the Zn anodes.The negatively-charged cavities in the zeolite lattice provide highly accessible migration channels for Zn^(2+),while blocking anions and electrolyte from passing through.This low-cost cation-exchange protecting layer can simultaneously suppress self-discharge,anode corrosion/passivation,and Zn dendrite growth,awarding the Zn||I_(2) batteries with ultra-long cycle life(91.92%capacity retention after 5600 cycles at 2 A g^(−1)),high coulombic efficiencies(99.76%in average)and large capacity(203–196 mAh g^(−1) at 0.2 A g^(−1)).This work provides a highly affordable approach for the construction of high-performance Zn-I_(2) aqueous batteries.
基金Japan Society for the Promotion of Science,Grant/Award Number:18H03869National Natural Science Foundation of China,Grant/Award Numbers:51872333,51874357。
文摘Silicon(Si)has been attracting extensive attention for rechargeable lithium(Li)‐ion batteries due to its high theoretical capacity and low potential vs Li/Li+.However,it remains challenging and problematic to stabilize the Si materials during electrochemical cycling because of the huge volume expansion,which results in losing electric contact and pulverization of Si particles.Consequently,the Si anode materials generally suffer from poor cycling,poor rate performance,and low coulomb efficiency,preventing them from practical applications.Up‐to‐date,there are numerous reports on the engineering of Si anode materials at microscale and nanoscale with significantly improved electrochemical performances.In this review,we will concentrate on various precisely designed protective layers for silicon‐based materials,including carbon layers,inorganic layers,and conductive polymer protective layer.First,we briefly introduced the alloying and failure mechanism of Si as anode materials upon electrochemical reactions.Following that,representative cases have been introduced and summarized to illustrate the purpose and advancement of protective coating layers,for instance,to alleviate pulverization and improve conductivity caused by volume expansion of Si particles during charge/discharge process,and maintain the surface stability of Si particles to form a stable solid‐electrolyte interphase layer.At last,possible strategies on the protective coating layer for stabilizing silicon anode materials that can be applied in the future have been indicated.
文摘In order to solve coal and gas outbursts during mining coal seam,studying on related problems were carried out. According to the theories of mining upper protective layer,proper mining plan were designed and performed through field experiment. By means of examining several parameters obtained from the field experiment,the protective effects were evaluated and the protective scope and related parameters were determined. The results of field experiment show that the danger of outbursts was evidently eliminated and the method of mining protective layers is effective and the safety and economic benefits are remarkable. The research has really applied worth and will give beneficial references to mining area with analogous conditions.
基金Supported by the National Natural Science Foundation of China （51004003） the Natural Science Foundation of Ministry of Education of Anhui Province （K J2010A091 ）
文摘Based on the occurrence features of Group B coal-seams at a coal mine in the Huainan coal mining area, the elasto-plastic mechanical damage constitutive functions and numerical model for the protective layer excavation were established. With the UDEC2D computer program, after the upper protective layer was mined, the stress field change trends, crack development, and expansion deformation trends of underlying coal rock seams in the floor of the working face were simulated and analyzed. The simulation results show the stress changes in coal rock seams, the evolution process of pre-cracks during the process of upper protective layer mining, the caved zone and fractured zone of the underlying coal rock seams. At the same time, the results from the actual investigation and analysis of protected layer deformation match the simulation values, which verifies the validity and accuracy of numerical simulation results. The study results have an important guiding significance for gas management in low permeability and high gas coal seams with similar mining conditions.
文摘In order to understand the effect of mining height and floor lithology at the upper protective layer face on the pressure relief of protected coal seams, this paper uses a numerical simulation method to model the pressure changes at protected coal seam during mining upper protective layer. The results show that the taller the mining height at the upper protective layer face, the greater the protection on protected coal seam due to the higher level of pressure release; the upper protective layer face with hard rock floor impedes the pressure release at the protected coal seam, which affects the overall effect of the pressure release at protected coal seam using the protective layer mining method.
