The inherent safety,high theoretical specific capacity and low raw material cost of aqueous batteries make them potential candidates in large-scale energy storage.However,uncontrolled dendrite growth,parasitic reactio...The inherent safety,high theoretical specific capacity and low raw material cost of aqueous batteries make them potential candidates in large-scale energy storage.However,uncontrolled dendrite growth,parasitic reactions and sluggish mass transfer on the anode-electrolyte interface are the main challenges restricting the application prospect of aqueous zinc-ion batteries.In general,eukaryotic cells utilize specific ion channels to achieve ion migration with the merits of low energy consumption and rapid speed.Herein,migrating the concept of ion channels to aqueous batteries,a crown species encapsulated zeolitic imidazolate framework(ZIF)interfacial layer(denoted as ZIF@Crown)was ex situ decorated onto the Zn anode.Similar to biological ion channels,the ZIF@Crown layer can homogenize the distribution of Zn^(2+)on the anode,accelerate the desolvation of hydrated Zn^(2+)and reduce the energy barrier for Zn^(2+)deposition,which were verified by theoretical calculations and experimental characterizations.Benefiting from these efficacious modulation mechanisms,the Zn@ZIF@Crown symmetrical cell could achieve a long calendar life of over 1900 h and the Zn@ZIF@Crown||Cu also sustained 600 cycles with a high Coulombic efficiency(97%).Furthermore,the full cells containing ZIF@Crown layer exhibit desirable electrochemical performance.This work provides an innovative avenue toward the optimization of aqueous batteries via bionic interfacial engineering.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
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
Rechargeable aqueous zinc(Zn)-metal batteries hold great promise for next-generation energy storage systems.However,their practical application is hindered by several challenges,including dendrite formation,corrosion,...Rechargeable aqueous zinc(Zn)-metal batteries hold great promise for next-generation energy storage systems.However,their practical application is hindered by several challenges,including dendrite formation,corrosion,and the competing hydrogen evolution reaction.To address these issues,we designed and fabricated a composite protective layer for Zn anodes by integrating carbon nanotubes(CNTs)with chitosan through a simple and scalable scraping process.The CNTs ensure uniform electric field distribution due to their high electrical conductivity,while protonated chitosan regulates ion transport and suppresses dendrite formation at the anode interface.The chitosan/CNTs composite layer also facilitates smooth Zn^(2+)deposition,enhancing the stability and reversibility of the Zn anode.As a result,the chitosan/CNTs@Zn anode demonstrates exceptional cycling stability,achieving over 3000 h of plating/stripping with minimal degradation.When paired with a V_(2)O_(5)cathode,the composite-protected anode significantly improves the cycle stability and energy density of the full cell.Techno-economic analysis confirms that batteries incorporating the chitosan/CNTs protective layer outperform those with bare Zn anodes in terms of energy density and overall performance under optimized conditions.This work provides a scalable and sustainable strategy to overcome the critical challenges of aqueous Zn-metal batteries,paving the way for their practical application in next-generation energy storage systems.展开更多
In this work,we design and fabricate AlGaN/GaN-based Schottky barrier diodes(SBDs)on a silicon substrate with a trenched n^(+)-GaN cap layer.With the developed physical models,we find that the n^(+)-GaN cap layer prov...In this work,we design and fabricate AlGaN/GaN-based Schottky barrier diodes(SBDs)on a silicon substrate with a trenched n^(+)-GaN cap layer.With the developed physical models,we find that the n^(+)-GaN cap layer provides more electrons into the AlGaN/GaN channel,which is further confirmed experimentally.When compared with the reference device,this increases the two-dimensional electron gas(2DEG)density by two times and leads to a reduced specific ON-resistance(Ron,sp)of~2.4 mΩ·cm^(2).We also adopt the trenched n^(+)-GaN structure such that partial of the n^(+)-GaN is removed by using dry etching process to eliminate the surface electrical conduction when the device is set in the off-state.To suppress the surface defects that are caused by the dry etching process,we also deposit Si_(3)N_(4)layer prior to the deposition of field plate(FP),and we obtain a reduced leakage current of~8×10^(−5)A·cm^(−2)and breakdown voltage(BV)of 876 V.The Baliga’s figure of merit(BFOM)for the proposed structure is increased to~319 MW·cm^(−2).Our investigations also find that the pre-deposited Si_(3)N_(4)layer helps suppress the electron capture and transport processes,which enables the reduced dynamic R_(on,sp).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
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
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
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
Anode free lithium metal batteries(AF-LMBs)have conspicuous advantages both in energy density and the compatibility of battery manufacturing process.However,the limited cycle life of AF-LMBs is a crucial factor hinder...Anode free lithium metal batteries(AF-LMBs)have conspicuous advantages both in energy density and the compatibility of battery manufacturing process.However,the limited cycle life of AF-LMBs is a crucial factor hindering its practical application.Fluorinated or nitride artificial inorganic solid electrolyte interphase(SEI)has been found as an effective method to prolong the lifespan of AF-LMBs.Herein,by investigating the impact of nano-sized inorganic gradient layers(LiF or Li3N)on initial Li deposition behavior,we notice that the Li^(+) diffusion barrier and the deposition morphology are highly depended on the thickness of inorganic layers.Thicker protective layers cause larger overpotential as well as more aggregated Li^(+) distribution.This study reveals that the ideal SEI should be synthesized thin and uniformly enough and uncontrollable artificial SEI can cause damage to the lifespan of AF-LMBs.展开更多
The electrochemical utilization of Zn anodes in aqueous batteries is hampered by the intricate and interconnected issues of Zn dendrite growth,H_(2)evolution and Zn corrosion reactions.In this study,a multifunctional ...The electrochemical utilization of Zn anodes in aqueous batteries is hampered by the intricate and interconnected issues of Zn dendrite growth,H_(2)evolution and Zn corrosion reactions.In this study,a multifunctional protective layer comprising MXene and graphitic carbon nitride(g-C_(3)N_(4))was constructed using a self-assembly strategy.The MXene/g-C_(3)N_(4)protective layer exhibited robust zincophilic characteristics,which facilitated a uniform distribution of the electric field and ensured a sufficient influx of Zn^(2+).This reduces the Zn^(2+)nucleation barrier and prevents dendrite growth.In addition,the hydrophobic nature of the protective layer,coupled with its negative charge,can repel SO_(4)^(2-)and select water molecules from the electrolyte,which aids in mitigating corrosion and H_(2)evolution.The symmetric Zn cell coated with the MXene/g-C_(3)N_(4)protective layer showed remarkable stability,achieving over 2000 h of reversible cycling at1 mA·cm^(-2).Furthermore,the MXene/g-C_(3)N_(4)-coated Zn anode paired with a sodium-doped V_(2)O_5cathode(NVO)exhibited enhanced cycling capability over 1500 cycles.展开更多
Aqueous zinc-ion batteries(AZIBs)are promising for future large-scale energy storage systems,however,suffer from inferior cycling life due to the dendrites growth and side reaction on Zn metal anode.Herein,a fast ion ...Aqueous zinc-ion batteries(AZIBs)are promising for future large-scale energy storage systems,however,suffer from inferior cycling life due to the dendrites growth and side reaction on Zn metal anode.Herein,a fast ion conductor Na_(5)YSi_(4)O_(12)(NYSO)was synthesized and fabricated as a protection layer of the Zn metal anode.By adjusting the thickness,an optimized NYSO coating of 20.3μm was obtained and the corresponding symmetry cell demonstrates an extended life span of 1896 h at the current density of 0.5 mA cm^(−2).In addition,a favorable rate performance of the NYSO@Zn anode at a high current density of 10 mA cm^(−2)was achieved.Benefiting from the NYSO coating,uniform diffusion and deposition of Zn^(2+)on the Zn anode could be realized,leading to the elimination of Zn dendrites and side reactions.Therefore,the aqueous NYSO@Zn|CNT@MnO_(2)full cell shows superior capacity and cycling stability to that of the bare Zn full cell.展开更多
All-solid-state batteries(ASSBs)have garnered significant interest as the next-generation in battery technology,praised for their superior safety and high energy density.However,a conductive agent accelerates the unde...All-solid-state batteries(ASSBs)have garnered significant interest as the next-generation in battery technology,praised for their superior safety and high energy density.However,a conductive agent accelerates the undesirable side reactions of sulfide-based solid electrolytes(SEs),resulting in poor electrochemical properties with increased interfacial resistance.Here,we propose a wet chemical method rationally designed to achieve a conformal coating of lithium-indium chloride(Li_(3)InCl_(6))onto vapor-grown carbon fibers(VGCFs)as conductive agents.First,with the advantage of the Li_(3)InCl_(6) protective layer,use of VGCF@Li_(3)InCl_(6) leads to enhanced interfacial stability and improved electrochemical properties,including stable cycle performance.These results indicate that the Li_(3)InCl_(6) protective layer suppresses the unwanted reaction between Li_(6)PS_(5)Cl(LPSCl)and VGCF.Second,VGCF@Li_(3)InCl_(6) effectively promotes polytetrafluoroethylene(PTFE)fibrillization,leading to a homogeneous electrode microstructure.The uniform distribution of the cathode active material(CAM)in the electrode results in reduced charge-transfer resistance(R_(ct))and enhanced Li-ion kinetics.As a result,a full cell with the LiNi_(x)Mn_(y)Co_(z)O_(2)(NCM)/VGCF@Li_(3)InCl_(6) electrode shows an areal capacity of 7.7mAhcm^(−2) at 0.05 C and long-term cycle stability of 77.9%over 400 cycles at 0.2 C.This study offers a strategy for utilizing stable carbon-based conductive agents in sulfide-based ASSBs to enhance their electrochemical performance.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
Aqueous zinc-ion batteries are regarded as promising electrochemical energy-storage systems for various applications because of their high safety,low costs,and high capacities.However,dendrite formation and side react...Aqueous zinc-ion batteries are regarded as promising electrochemical energy-storage systems for various applications because of their high safety,low costs,and high capacities.However,dendrite formation and side reactions during zinc plating or stripping greatly reduce the capacity and cycle life of a battery and subsequently limit its practical application.To address these issues,we modified the surface of a zinc anode with a functional bilayer composed of zincophilic Cu and flexible polymer layers.The zincophilic Cu interfacial layer was prepared through CuSO_(4)solution pretreatment to serve as a nucleation site to facilitate uniform Zn deposition.Meanwhile,the polymer layer was coated onto the Cu interface layer to serve as a protective layer that would prevent side reactions between zinc and electrolytes.Benefiting from the synergistic effect of the zincophilic Cu and protective polymer layers,the symmetric battery exhibits an impressive cycle life,lasting over 2900 h at a current density of 1 m A·cm^(-2)with a capacity of 1 m A·h·cm^(-2).Moreover,a full battery paired with a vanadium oxide cathode achieves a remarkable capacity retention of 72%even after 500 cycles.展开更多
The effective optimization of Zn anode/protective layer interface stability,underpinned by an in-depth exploration of durable protection mechanisms,is crucial for developing artificial protective layers in high-perfor...The effective optimization of Zn anode/protective layer interface stability,underpinned by an in-depth exploration of durable protection mechanisms,is crucial for developing artificial protective layers in high-performance aqueous Zn-ion batteries(AZIBs).In this work,we present a self-regulating,continuous and dense amorphous Al_(2)O_(3-x)-2 layer(referred to as A-Al_(2)O_(3-x)-2 layer)with exceptional mechanical strength,achieved through core process control.Spectroscopic and theoretical studies reveal that the amorphous structure of Al_(2)O_(3-x)-2,featuring stable oxygen vacancies,significantly enhances Zn^(2+)transfer kinetics and promotes uniform distribution.This unique structure guides controlled Zn deposition along the(002)plane,facilitating stable cycling.Furthermore,the excellent mechanical strength of A-Al_(2)O_(3-x)-2@Zn is well maintained under extended cycling conditions,ensuring lasting interface integrity and durable protection.Under a challenging current density of 60 mA cm^(-2),the A-Al_(2)O_(3-x)-2@Zn symmetric cell demonstrates an impressive cycling lifespan of 9620 cycles.Furthermore,a full cell assembled with an A-Al_(2)O_(3-x)-2@Zn anode and an Al^(3+)-doped MnO_(2)cathode exhibits substantially improved cycling performance with 100% capacity retention after 900 cycles at 1 A g^(-1),underscoring the importance of the synergistic effects between anode and cathode materials in achieving long-life AZIBs,This work provides valuable insights into designing durable protective layers for Zn anodes in aqueous Zn-ion batteries.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
基金supported by research grants from the National Key Research and Development Program of China(No.2022YFB3803300)the Natural Science Foundation of China(Nos.52173235 and 62074022)+2 种基金the Venture&Innovation Support Program for Chongqing Overseas Returnees(No.CX2021018)the Youth Talent Support Program of Chongqing(No.CQYC2021059206)the Program of Graduate Education and Teaching in Chongqing(No.yjg223016).
文摘The inherent safety,high theoretical specific capacity and low raw material cost of aqueous batteries make them potential candidates in large-scale energy storage.However,uncontrolled dendrite growth,parasitic reactions and sluggish mass transfer on the anode-electrolyte interface are the main challenges restricting the application prospect of aqueous zinc-ion batteries.In general,eukaryotic cells utilize specific ion channels to achieve ion migration with the merits of low energy consumption and rapid speed.Herein,migrating the concept of ion channels to aqueous batteries,a crown species encapsulated zeolitic imidazolate framework(ZIF)interfacial layer(denoted as ZIF@Crown)was ex situ decorated onto the Zn anode.Similar to biological ion channels,the ZIF@Crown layer can homogenize the distribution of Zn^(2+)on the anode,accelerate the desolvation of hydrated Zn^(2+)and reduce the energy barrier for Zn^(2+)deposition,which were verified by theoretical calculations and experimental characterizations.Benefiting from these efficacious modulation mechanisms,the Zn@ZIF@Crown symmetrical cell could achieve a long calendar life of over 1900 h and the Zn@ZIF@Crown||Cu also sustained 600 cycles with a high Coulombic efficiency(97%).Furthermore,the full cells containing ZIF@Crown layer exhibit desirable electrochemical performance.This work provides an innovative avenue toward the optimization of aqueous batteries via bionic interfacial engineering.
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.
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supported by the National Natural Science Foundation of China(22279139,62227815,22465026,22469015)the National Key R&D Program of China(2022YFA1504500)+1 种基金the Natural Science Foundation of Inner Mongolia Autonomous Region of China(2024JQ06,2022MS2010,2024MS05005)Inner Mongolia University Postgraduate Scientific Research Innovation Project(11200-5223737)。
文摘Rechargeable aqueous zinc(Zn)-metal batteries hold great promise for next-generation energy storage systems.However,their practical application is hindered by several challenges,including dendrite formation,corrosion,and the competing hydrogen evolution reaction.To address these issues,we designed and fabricated a composite protective layer for Zn anodes by integrating carbon nanotubes(CNTs)with chitosan through a simple and scalable scraping process.The CNTs ensure uniform electric field distribution due to their high electrical conductivity,while protonated chitosan regulates ion transport and suppresses dendrite formation at the anode interface.The chitosan/CNTs composite layer also facilitates smooth Zn^(2+)deposition,enhancing the stability and reversibility of the Zn anode.As a result,the chitosan/CNTs@Zn anode demonstrates exceptional cycling stability,achieving over 3000 h of plating/stripping with minimal degradation.When paired with a V_(2)O_(5)cathode,the composite-protected anode significantly improves the cycle stability and energy density of the full cell.Techno-economic analysis confirms that batteries incorporating the chitosan/CNTs protective layer outperform those with bare Zn anodes in terms of energy density and overall performance under optimized conditions.This work provides a scalable and sustainable strategy to overcome the critical challenges of aqueous Zn-metal batteries,paving the way for their practical application in next-generation energy storage systems.
基金supported by National Natural Science Foundation of China under grant U23A20361Key Area R&D Program of Guangdong Province under grant 2022B0701180001.
文摘In this work,we design and fabricate AlGaN/GaN-based Schottky barrier diodes(SBDs)on a silicon substrate with a trenched n^(+)-GaN cap layer.With the developed physical models,we find that the n^(+)-GaN cap layer provides more electrons into the AlGaN/GaN channel,which is further confirmed experimentally.When compared with the reference device,this increases the two-dimensional electron gas(2DEG)density by two times and leads to a reduced specific ON-resistance(Ron,sp)of~2.4 mΩ·cm^(2).We also adopt the trenched n^(+)-GaN structure such that partial of the n^(+)-GaN is removed by using dry etching process to eliminate the surface electrical conduction when the device is set in the off-state.To suppress the surface defects that are caused by the dry etching process,we also deposit Si_(3)N_(4)layer prior to the deposition of field plate(FP),and we obtain a reduced leakage current of~8×10^(−5)A·cm^(−2)and breakdown voltage(BV)of 876 V.The Baliga’s figure of merit(BFOM)for the proposed structure is increased to~319 MW·cm^(−2).Our investigations also find that the pre-deposited Si_(3)N_(4)layer helps suppress the electron capture and transport processes,which enables the reduced dynamic R_(on,sp).
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.
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 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supported by the National Natural Scientific Foundation of China(No.22379014)Shanxi key research and development program(No.202102060301011)。
文摘Anode free lithium metal batteries(AF-LMBs)have conspicuous advantages both in energy density and the compatibility of battery manufacturing process.However,the limited cycle life of AF-LMBs is a crucial factor hindering its practical application.Fluorinated or nitride artificial inorganic solid electrolyte interphase(SEI)has been found as an effective method to prolong the lifespan of AF-LMBs.Herein,by investigating the impact of nano-sized inorganic gradient layers(LiF or Li3N)on initial Li deposition behavior,we notice that the Li^(+) diffusion barrier and the deposition morphology are highly depended on the thickness of inorganic layers.Thicker protective layers cause larger overpotential as well as more aggregated Li^(+) distribution.This study reveals that the ideal SEI should be synthesized thin and uniformly enough and uncontrollable artificial SEI can cause damage to the lifespan of AF-LMBs.
基金financially supported by the Natural Science Foundation of Hunan Province(No.2020JJ4684)the National Natural Science Foundation of China(No.52104315)+1 种基金the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.52121004)the Open Project of the Key Laboratory of digital flavor research of Hunan China Tobacco Industry Co.,Ltd(No.202143000834024)。
文摘The electrochemical utilization of Zn anodes in aqueous batteries is hampered by the intricate and interconnected issues of Zn dendrite growth,H_(2)evolution and Zn corrosion reactions.In this study,a multifunctional protective layer comprising MXene and graphitic carbon nitride(g-C_(3)N_(4))was constructed using a self-assembly strategy.The MXene/g-C_(3)N_(4)protective layer exhibited robust zincophilic characteristics,which facilitated a uniform distribution of the electric field and ensured a sufficient influx of Zn^(2+).This reduces the Zn^(2+)nucleation barrier and prevents dendrite growth.In addition,the hydrophobic nature of the protective layer,coupled with its negative charge,can repel SO_(4)^(2-)and select water molecules from the electrolyte,which aids in mitigating corrosion and H_(2)evolution.The symmetric Zn cell coated with the MXene/g-C_(3)N_(4)protective layer showed remarkable stability,achieving over 2000 h of reversible cycling at1 mA·cm^(-2).Furthermore,the MXene/g-C_(3)N_(4)-coated Zn anode paired with a sodium-doped V_(2)O_5cathode(NVO)exhibited enhanced cycling capability over 1500 cycles.
基金supported by National Natural Science Foundation of China with Grant No.12274176 and 51972142support from the Fundamental Research Funds for the Center Universities,and Department of Science and Technology of Jilin Province with Grant No.20220201118GX.
文摘Aqueous zinc-ion batteries(AZIBs)are promising for future large-scale energy storage systems,however,suffer from inferior cycling life due to the dendrites growth and side reaction on Zn metal anode.Herein,a fast ion conductor Na_(5)YSi_(4)O_(12)(NYSO)was synthesized and fabricated as a protection layer of the Zn metal anode.By adjusting the thickness,an optimized NYSO coating of 20.3μm was obtained and the corresponding symmetry cell demonstrates an extended life span of 1896 h at the current density of 0.5 mA cm^(−2).In addition,a favorable rate performance of the NYSO@Zn anode at a high current density of 10 mA cm^(−2)was achieved.Benefiting from the NYSO coating,uniform diffusion and deposition of Zn^(2+)on the Zn anode could be realized,leading to the elimination of Zn dendrites and side reactions.Therefore,the aqueous NYSO@Zn|CNT@MnO_(2)full cell shows superior capacity and cycling stability to that of the bare Zn full cell.
基金supported by the Korea Institute for Advancement of Technology(KIAT)grant funded by the Korean Government(MOTIE)(RS-2024-00417730,HRD Program for Industrial Innovation)supported by the Technology Innovation Program(or Industrial Strategic Technology Development Program-Materials&Components Technology Development Program)(20024261),Development of thick film electrodes and cell manufacturing technology for a high-performance lithium iron phosphate battery with energy density of over 200 Wh/kg was funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea).
文摘All-solid-state batteries(ASSBs)have garnered significant interest as the next-generation in battery technology,praised for their superior safety and high energy density.However,a conductive agent accelerates the undesirable side reactions of sulfide-based solid electrolytes(SEs),resulting in poor electrochemical properties with increased interfacial resistance.Here,we propose a wet chemical method rationally designed to achieve a conformal coating of lithium-indium chloride(Li_(3)InCl_(6))onto vapor-grown carbon fibers(VGCFs)as conductive agents.First,with the advantage of the Li_(3)InCl_(6) protective layer,use of VGCF@Li_(3)InCl_(6) leads to enhanced interfacial stability and improved electrochemical properties,including stable cycle performance.These results indicate that the Li_(3)InCl_(6) protective layer suppresses the unwanted reaction between Li_(6)PS_(5)Cl(LPSCl)and VGCF.Second,VGCF@Li_(3)InCl_(6) effectively promotes polytetrafluoroethylene(PTFE)fibrillization,leading to a homogeneous electrode microstructure.The uniform distribution of the cathode active material(CAM)in the electrode results in reduced charge-transfer resistance(R_(ct))and enhanced Li-ion kinetics.As a result,a full cell with the LiNi_(x)Mn_(y)Co_(z)O_(2)(NCM)/VGCF@Li_(3)InCl_(6) electrode shows an areal capacity of 7.7mAhcm^(−2) at 0.05 C and long-term cycle stability of 77.9%over 400 cycles at 0.2 C.This study offers a strategy for utilizing stable carbon-based conductive agents in sulfide-based ASSBs to enhance their electrochemical performance.
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.
基金financially supported by the Science and Technology Development Project of Henan Province,China(No.242102241042)the Joint Fund of Henan Province Science and Technology R&D Program(No.225200810093)+1 种基金the Startup Research of Henan Academy of Sciences(No.231817001)the Key Innovation Projects for Postgraduates of Henan Academy of Sciences(No.24331712)。
文摘Aqueous zinc-ion batteries are regarded as promising electrochemical energy-storage systems for various applications because of their high safety,low costs,and high capacities.However,dendrite formation and side reactions during zinc plating or stripping greatly reduce the capacity and cycle life of a battery and subsequently limit its practical application.To address these issues,we modified the surface of a zinc anode with a functional bilayer composed of zincophilic Cu and flexible polymer layers.The zincophilic Cu interfacial layer was prepared through CuSO_(4)solution pretreatment to serve as a nucleation site to facilitate uniform Zn deposition.Meanwhile,the polymer layer was coated onto the Cu interface layer to serve as a protective layer that would prevent side reactions between zinc and electrolytes.Benefiting from the synergistic effect of the zincophilic Cu and protective polymer layers,the symmetric battery exhibits an impressive cycle life,lasting over 2900 h at a current density of 1 m A·cm^(-2)with a capacity of 1 m A·h·cm^(-2).Moreover,a full battery paired with a vanadium oxide cathode achieves a remarkable capacity retention of 72%even after 500 cycles.
基金financially supported by the National Natural Science Foundation of China(42377487,42307582)the Guangdong Basic and Applied Basic Research Foundation(2022A1515110477,2022B1515120019)Support Project of Guangzhou Association for Science and Technology(QT2024-07)。
文摘The effective optimization of Zn anode/protective layer interface stability,underpinned by an in-depth exploration of durable protection mechanisms,is crucial for developing artificial protective layers in high-performance aqueous Zn-ion batteries(AZIBs).In this work,we present a self-regulating,continuous and dense amorphous Al_(2)O_(3-x)-2 layer(referred to as A-Al_(2)O_(3-x)-2 layer)with exceptional mechanical strength,achieved through core process control.Spectroscopic and theoretical studies reveal that the amorphous structure of Al_(2)O_(3-x)-2,featuring stable oxygen vacancies,significantly enhances Zn^(2+)transfer kinetics and promotes uniform distribution.This unique structure guides controlled Zn deposition along the(002)plane,facilitating stable cycling.Furthermore,the excellent mechanical strength of A-Al_(2)O_(3-x)-2@Zn is well maintained under extended cycling conditions,ensuring lasting interface integrity and durable protection.Under a challenging current density of 60 mA cm^(-2),the A-Al_(2)O_(3-x)-2@Zn symmetric cell demonstrates an impressive cycling lifespan of 9620 cycles.Furthermore,a full cell assembled with an A-Al_(2)O_(3-x)-2@Zn anode and an Al^(3+)-doped MnO_(2)cathode exhibits substantially improved cycling performance with 100% capacity retention after 900 cycles at 1 A g^(-1),underscoring the importance of the synergistic effects between anode and cathode materials in achieving long-life AZIBs,This work provides valuable insights into designing durable protective layers for Zn anodes in aqueous Zn-ion batteries.
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.