High-performance lithium-ion batteries and sodium-ion batteries have been developed utilizing a hybrid anode material composed of zinc sulfide/sulfurized polyacrylonitrile.The in situ-generated zinc sulfide nanopartic...High-performance lithium-ion batteries and sodium-ion batteries have been developed utilizing a hybrid anode material composed of zinc sulfide/sulfurized polyacrylonitrile.The in situ-generated zinc sulfide nanoparticles serve as catalytic agents,significantly enhancing conductivity,shortening diffusion paths,and accelerating reaction kinetics.Simultaneously,the sulfurized polyacrylonitrile fibers form a three-dimensional matrix that not only provides a continuous network for rapid electron transfer but also prevents zinc sulfide nanoparticle aggregation and mitigates volume changes during charge-discharge cycles.Moreover,the heterointerface structure at the junction of zinc sulfide nanoparticles and the sulfurized polyacrylonitrile matrix increases the availability of active sites and facilitates both ion adsorption and electron transfer.As an anode material for lithium-ion batteries,the zinc sulfide/sulfurized polyacrylonitrile hybrid demonstrates a high reversible capacity of 1178 mAh g^(-1)after 100 cycles at a current density of 0.2 A g^(-1),maintaining a capacity of 788 mAh g^(-1)after 200 cycles at 1 A g^(-1).It also exhibits excellent sodium storage capabilities,retaining a capacity of 625 mAh g^(-1)after 150 cycles at 0.2 A g^(-1).Furthermore,ex-situ X-ray photoelectron spectroscopy,X-ray diffraction,7Li solid-state magic angle spinning nuclear magnetic resonance,and in situ Raman are employed to investigate the reaction mechanisms of the zinc sulfide/sulfurized polyacrylonitrile hybrid anode,providing valuable insights that pave the way for the advancement of hybrid anode materials in lithium-ion batteries and sodium-ion batteries.展开更多
Despite sulfurization offers the advantage of improving the photovoltaic performance in preparing Cu(In,Ga)Se2(CIGS)absorbers,deep level defects in the absorber and poor energy level alignment on the front surface are...Despite sulfurization offers the advantage of improving the photovoltaic performance in preparing Cu(In,Ga)Se2(CIGS)absorbers,deep level defects in the absorber and poor energy level alignment on the front surface are still main obstacles limiting the improvement of power co nversion efficiency(PCE)in sulfided CIGS solar cells.Herein,an in-situ Na doping strategy is proposed,in which the tailing effect of crystal growth is used to promote the sulfurization of CIGS absorbers.It is found that the grain growth is supported by Na incorporating due to the enrichment of NaSe_(x)near the upper surface.The high soluble Na during grain growth can not only suppress intrinsic In_(Cu) donor defects in the absorber,but also tailor S distribution in bulk and the band alignment at the heterojunction,which are both beneficial for the effective electron carriers.Meanwhile,the Na aggregation near the bottom of the absorber also contributes to the crystalline quality increasing and favorable ultra-thin MoSe_(2) formation at back contact,resulting in a reduced barrier height conducive to hole transport.PCE of the champion device is as high as 16.76%with a 28%increase.This research offers new insights into synthesizing CIGS solar cells and other chalcogenide solar cells with superior cell performance when using an intense sulfurization process.展开更多
Sulfurized polyacrylonitrile(SPAN)represents a unique class of cathode material for lithium sulfur(Li-S)batteries as it eradicates the polysulfides shuttling issue in carbonate-based electrolyte.However,due to the ess...Sulfurized polyacrylonitrile(SPAN)represents a unique class of cathode material for lithium sulfur(Li-S)batteries as it eradicates the polysulfides shuttling issue in carbonate-based electrolyte.However,due to the essential chemical S-linking and organic nature of SPAN,the active mass percentage and rate capability are two bottleneck issues preventing its ultimate deployment outside of laboratories.In the current work,aiming to endow both the charge conductivity and catalytic activity to SPAN for maximizing the redox kinetics of S conversion,a freestanding nanofibrous SPAN cathode embedding conductive CNTs and atomically dispersed Co centers is fabricated via multivariate electrospinning.While the CNTs enable dramatically enhancing the fiber conductivity and generating mesoscopic porosity for facilitating charge and mass transportation,the cross-linking of SPAN by Co-N_(4) S motifs creates extra charge conduction pathways and further serves as the catalytic active sites for expediting redox S conversion.As a result,an extraordinary Li-SPAN performance is achieved with a high specific capacity up to 1856 mAh g^(-1)@0.2 C,a superb rate capability up to 10 C,and an ultra-long battery life up to 1500 cycles@1 C.Consequently,our study here provides insights into the adoption of coordination chemistry to maximize the sulfur utilization by ensuring a more complete redox conversion from SPAN to Li2 S,and vice versa.展开更多
The inclusion complex of fl-cyclodextrin （β-CD） and sulfurized isobutylene （T321） was prepared with a co-precipitation method. The tribological properties of the complex with different concentrations were investi...The inclusion complex of fl-cyclodextrin （β-CD） and sulfurized isobutylene （T321） was prepared with a co-precipitation method. The tribological properties of the complex with different concentrations were investigated by a four-ball tester in the solution of polyethylene glycol-600 （PEG-600）. The experimental results suggest that the complex exhibits better anti-friction and anti-wear properties than fl-CD under different load conditions. The tribo-system shows the least friction coefficient when the concentration of the complex is 0.8%. During the friction process, the complex was decomposed into various molecular fragments and the T321 molecules were released onto the friction interface to provide effective lubrication. The XPS analytical results on the worn surfaces reveal that sulfide film formed by the released T321 plays a major role, and the iron alkoxide and carbon deposition films formed by the β-CD fragments have better anti-friction effect on the sulfide film surface. The interactions of different films result in the formation of a mixed boundary lubrication film.展开更多
Sulfurized polyacrylonitrile(SPAN)as a promising cathode material for lithium sulfur(Li-S)batteries has drawn increasing attention for its improved electrochemical performance in carbonate-based electrolyte.However,th...Sulfurized polyacrylonitrile(SPAN)as a promising cathode material for lithium sulfur(Li-S)batteries has drawn increasing attention for its improved electrochemical performance in carbonate-based electrolyte.However,the relatively poor electronic and ionic conductivities of SPAN limit its high-rate and lowtemperature performances.In this work,a novel one-dimensional nanofiber SPAN(SFPAN)composite is developed as the cathode material for Li-S batteries.Benefitting from its one-dimensional nanostructure,the SFPAN composite cathode provides fast channels for the migration of ions and electronics,thus effectively improving its electrochemical performance at high rates and low temperature.As a result,the SFPAN maintains a high reversible specific capacity^1200 mAh g−1 after 400 cycles at 0.3 A g−1 and can deliver a high capacity of^850 mAh g−1 even at a high current density of 12.5 A g−1.What is more,the SFPAN can achieve a capacity of^800 mAh g−1 at 0℃and^1550 mAh g−1 at 60℃,thus providing a wider temperature range of applications.This work provides new perspectives on the cathode design for high-rate lithium-sulfur batteries.展开更多
The inclusion complex of β-cyclodextrin (β-CD) and sulfurized isobutylene (T321) was prepared with a co-precipitation method. The tribological properties of the complex with different concentrations were investigate...The inclusion complex of β-cyclodextrin (β-CD) and sulfurized isobutylene (T321) was prepared with a co-precipitation method. The tribological properties of the complex with different concentrations were investigated by a four-ball tester in the solution of polyethylene glycol-600 (PEG-600). The experimental results suggest that the complex exhibits better anti-friction and anti-wear properties than β-CD under different load conditions. The tribo-system shows the least friction coefficient when the concentration of the complex is 0.8%. During the friction process, the complex was decomposed into various molecular fragments and the T321 molecules were released onto the friction interface to provide effective lubrication. The XPS analytical results on the worn surfaces reveal that sulfide film formed by the released T321 plays a major role, and the iron alkoxide and carbon deposition films formed by the β-CD fragments have better anti-friction effect on the sulfide film surface. The interactions of different films result in the formation of a mixed boundary lubrication film.展开更多
Lithium–sulfur batteries have great potential for high energy applications due to their high capacities,low cost and eco-friendliness. However, the particularly rapid capacity decay owing to the dissolution and diffu...Lithium–sulfur batteries have great potential for high energy applications due to their high capacities,low cost and eco-friendliness. However, the particularly rapid capacity decay owing to the dissolution and diffusion of polysulfide intermediate into the electrolyte still hamper their practical applications.And the reported preparation procedures to sulfur based cathode materials are often complex, and hence are rather difficult to produce at large scale. Here, we report a simple mechano-chemical sulfurization methodology in vacuum environment applying ball-milling method combined both the chemical and physical interaction for the one-pot synthesis of edge-sulfurized grapheme nanoplatelets with 3D porous foam structure as cathode materials. The optimal sample of 70%S–Gn Ps-48 h(ball-milled 48 h) obtains 13.2 wt% sulfur that chemically bonded onto the edge of Gn Ps. And the assembled batteries exhibit high initial discharge capacities of 1089 mAh/g at 0.1 C and 950 mAh/g at 0.5 C, and retain a stable discharge capacity of 776 mAh/g after 250 cycles at 0.5 C with a high Coulombic efficiency of over 98%. The excellent performance is mainly attributed to the mechano-chemical interaction between sulfur and grapheme nanoplatelets. This definitely triggers the currently extensive research in lithium–sulfur battery area.展开更多
The wide application of electromagnetic technology has led to increasingly frequent information transmission and communication interconnection.When the intensity of the disordered radiation of electromagnetic waves is...The wide application of electromagnetic technology has led to increasingly frequent information transmission and communication interconnection.When the intensity of the disordered radiation of electromagnetic waves is too high,it will cause electromagnetic pollution and pose a huge threat to human health or the survival of other animals and plants.How to ingeniously design absorbing materials is the key to solving the problem.This paper proposes a new design concept.The Co-based zeolite imidazolite-structured material ZIF-67 was selected as the main body of the metal-organic frameworks(MOFs)template,and the dodecahedral structured ZIF-67 nanoparticles were prepared using the classic ion-ligand process.Subsequently,a dodecahedral NiCo-LDH nanoparticle precursor composed of NiCo bimetallic hydroxide nanosheets with hollow edges and interior was obtained based on the liquid-phase cationic etching process.On this basis,thioacetamide(TAA)was selected as the vulcanizing agent,and the ZIF-67-derived sulfide inheriting the micro-nano structure of the precursor was obtained through liquid-phase hydrothermal vulcanization.The vulcanization growth mechanism and electromagnetic wave absorption mechanism of the MOF_(S)-derived sulfide were deeply explored.展开更多
Potassium-ion batteries(PIBs)have garnered significant attention as a promising alternative to commercial lithium-ion batteries(LIBs)due to abundant and cost-efficient potassium reserves.However,the large size of pota...Potassium-ion batteries(PIBs)have garnered significant attention as a promising alternative to commercial lithium-ion batteries(LIBs)due to abundant and cost-efficient potassium reserves.However,the large size of potassium ions and the resulting sluggish reaction kinetics present major obstacles to the widespread use of PIBs.Herein,we present a simple method to ingeniously encapsulate SnS_(2)nanoparticles within sulfurized polyacrylonitrile(SPAN)fibers(SnS_(2)@SPAN)for serving as a high-performance PIB anode.The large interlayer spacing of SnS_(2)provides a fast transport channel for potassium ions during charge–discharge cycles,while the one-dimensional SPAN skeleton offers massive binding sites and shortens the diffusion path for potassium ions,facilitating faster reaction kinetics.Additionally,the excellent ductility of SPAN can effectively accommodate the large volume changes that occur in SnS_(2)upon potassium-ion insertion,thereby enhancing the cyclic stability of SnS_(2).Benefiting from the above advantages,the SnS_(2)@SPAN composites exhibit impressive cyclability over 500 cycles at 4 A g−1,with a capacity retention rate close to 100%.This study provides an effective approach for stabilizing high-capacity PIB anode materials with large volume variations.展开更多
Sulfurized polyacrylonitrile(SPAN)has emerged as an excellent cathode material for lithium–sulfur batteries(LiSBs),and it addresses the shuttle effect through a solid‒solid reaction.However,the actual sulfur loadings...Sulfurized polyacrylonitrile(SPAN)has emerged as an excellent cathode material for lithium–sulfur batteries(LiSBs),and it addresses the shuttle effect through a solid‒solid reaction.However,the actual sulfur loadings in SPAN often remain below 40 wt%.Due to the susceptibility of polysulfides-to-nucleophilic reactions with electrolytes,achieving physical encapsulation of elemental sulfur is a challenging task.In this study,a free-standing cathode material with a high sulfur/selenium(S/Se)loading of 55 wt%was fabricated by introducing SeS_(x) into the unique lotus root-like pores of porous SeS_(x)PAN nanofiber membranes by electrospinning and a two-step heat treatment.Insoluble compounds were formed due to nucleophilic interactions between lithium polyselenosulfides(LiSeSx)and the electrolyte,which potently blocked the existing lotus root-like pores and facilitated the creation of a thin cathode–electrolyte interphase on the fiber surface.This dual functionality of LiSeS_(x) safeguarded the active material embedded within the porous structure.The SeS_(15)PAN cathode exhibited remarkable cycling stability with almost no degradation after 200 cycles at 0.2 C,along with a high discharge capacity of 580 mAh/g.This approach presents a solution for addressing the insufficient sulfur content in SPAN.展开更多
Solid lithium-sulfur batteries(SLSBs)show potential for practical application due to their possibility for high energy density.However,SLSBs still face tough challenges such as the large interface impedance and lithiu...Solid lithium-sulfur batteries(SLSBs)show potential for practical application due to their possibility for high energy density.However,SLSBs still face tough challenges such as the large interface impedance and lithium dendrite formation.Herein,a highperformance SLSB is demonstrated by using a fiber network reinforced Li_(6.75)La_(3)Zr_(1.75)Ta_(0.25)O_(12)(LLZTO)based composite solid electrolyte(CSE)in combination with sulfurized polyacrylonitrile(SPAN)cathode.The CSE consisting of an electrospun polyimide(PI)film,LLZTO ionically conducting filler and polyacrylonitrile(PAN)matrix,which is named as PI-PAN/LLZTO CSE,possesses high room-temperature ionic conductivity(2.75×10^(-4)S/cm),high Li^(+)migration number(tLi+)of 0.67 and good interfacial wettability.SPAN is utilized due to its unique electrochemical properties:reasonable electronic conductivity and no polysulfides shuttle effect.The CSE enables a highly stable Li plating/stripping cycle for over 600 h and good rate performance.Moreover,the assembled SLSB exhibits good cycle performance of accomplishing 120 cycles at 0.2 C with the capacity retention of 474 mAh/g,good rate properties and excellent long-term cycling stability with a high capacity retention of 86.49%from 15^(th)to 1,000^(th)cycles at 1.0 C.This work rationalizes our design concept and may guide the future development of SLSBs.展开更多
Sulfurized polyacrylonitrile(S@pPAN)composite provides a conductive pathway for sulfur active material at the molecular level and has already become one of the most promising cathode materials in lithium-sulfur batter...Sulfurized polyacrylonitrile(S@pPAN)composite provides a conductive pathway for sulfur active material at the molecular level and has already become one of the most promising cathode materials in lithium-sulfur batteries because of its outstanding electrochemical performances via novel solid-solid conversion mechanism.Although there are a great number of researches on the S@pPAN composite material,the accurate structure of S@pPAN and its redox reaction mechanism during the charge-discharge process still have not been determined.The previous research and inferences about the structure of S@pPAN and its electrochemical reaction mechanism were summarized in this review,providing a reference for the future study of lithiumsulfur batteries.展开更多
Lithium-sulfur (Li-S) batteries have gained great attention due to the high theoretical energy density and low cost,yet their further commercialization has been obstructed by the notorious shuttle effect and sluggish ...Lithium-sulfur (Li-S) batteries have gained great attention due to the high theoretical energy density and low cost,yet their further commercialization has been obstructed by the notorious shuttle effect and sluggish redox dynamics.Herein,we supply a strategy to optimize the electron structure of Ni_(2)P by concurrently introducing B-doped atoms and P vacancies in Ni_(2)P (Vp-B-Ni_(2)P),thereby enhancing the bidirectional sulfur conversion.The study indicates that the simultaneous introduction of B-doped atoms and P vacancies in Ni_(2)P causes the redistribution of electron around Ni atoms,bringing about the upward shift of d-band center of Ni atoms and effective d-p orbital hybridization between Ni atoms and sulfur species,thus strengthening the chemical anchoring for lithium polysulfides (LiPSs) as well as expediting the bidirectional conversion kinetics of sulfur species.Meanwhile,theoretical calculations reveal that the incorporation of B-doped atoms and P vacancies in Ni_(2)P selectively promotes Li2S dissolution and nucleation processes.Thus,the Li-S batteries with Vp-B-Ni_(2)P-separators present outstanding rate ability of 777 m A h g^(-1)at 5 C and high areal capacity of 8.03 mA h cm^(-2)under E/S of 5μL mg^(-1)and sulfur loading of 7.20 mg cm^(-2).This work elucidates that introducing heteroatom and vacancy in metal phosphide collaboratively regulates the electron structure to accelerate bidirectional sulfur conversion.展开更多
The use of lithium-sulfur(Li-S)batteries is limited by sulfur redox reactions involving multi-phase transformations,especially at low-temperatures.To address this issue,we report a material(FCNS@NCFs)consisting of nit...The use of lithium-sulfur(Li-S)batteries is limited by sulfur redox reactions involving multi-phase transformations,especially at low-temperatures.To address this issue,we report a material(FCNS@NCFs)consisting of nitrogen-doped carbon fibers loaded with a ternary metal sulf-ide((Fe,Co,Ni)_(9)S_(8))for use as the sulfur host in Li-S batteries.This materi-al was prepared using transfer blot filter paper as the carbon precursor,thiourea as the source of nitrogen and sulfur,and FeCl_(3)·6H_(2)O,CoCl_(2)·6H_(2)O and NiCl_(2)·6H_(2)O as the metal ion sources.It was synthesized by an impreg-nation method followed by calcination.The nitrogen doping significantly in-creased the conductivity of the host,and the metal sulfides have excellent catalytic activities.Theoretical calculations,and adsorption and deposition experiments show that active sites on the surface of FCNS@NCFs selectively adsorb polysulfides,facilitate rapid adsorption and conversion,prevent cathode passivation and inhib-it the polysulfide shuttling.The FCNS@NCFs used as the sulfur host has excellent electrochemical properties.Its initial dis-charge capacity is 1639.0 mAh g^(−1) at 0.2 C and room temperature,and it remains a capacity of 1255.1 mAh g^(−1) after 100 cycles.At−20~C,it has an initial discharge capacity of 1578.5 mAh g^(−1) at 0.2 C,with a capacity of 867.5 mAh g^(−1) after 100 cycles.Its excellent performance at both ambient and low temperatures suggests a new way to produce high-performance low-temper-ature Li-S batteries.展开更多
A transformative beryllium metallurgy theory and method was proposed based on the low-temperature dissociation of hydrofluoric acid and purification by exploiting the large difference of fluoride solubility.Hydrofluor...A transformative beryllium metallurgy theory and method was proposed based on the low-temperature dissociation of hydrofluoric acid and purification by exploiting the large difference of fluoride solubility.Hydrofluoric acid can quickly dissociate berylum ore powder directly at low or room temperature with more than 99%dissociation rate.The solubility of AlF_(3),FeF_(3) CrF_(3) and MgF_(2),is low.Coupled with common ion effect,99.9%-purity beryllium products can be prepared without chemical purification.For high-purity beryllium products of grade 4N or higher,they can be prepared through the superior property that the pH intervals of iron,chromium,and other hydroxide precipitates are distinctly different from those corresponding to Be(OH)_(2),precipitates.This new method can be used to prepare most of the beryllium products that are prepared by modern beryllium metallurgy.展开更多
Lithium metal batteries(LMBs)have attracted great intention due to the high energy density[1].Among various battery technologies,lithium-sulfur(Li-S)batteries are also very unique but important due to its high energy ...Lithium metal batteries(LMBs)have attracted great intention due to the high energy density[1].Among various battery technologies,lithium-sulfur(Li-S)batteries are also very unique but important due to its high energy density,low cost and available sources[2].Although Li-s batteries exhibit high energy density,the cycling life is poor,especially for large-capacity pouch cells[3].The cycling performance of Li-s batteries is crucially determined by 16-electron complex sulfur reduction reaction(SRR)from S_(8)molecules to Li_(2)S,solid,which involves the multiple potential interwoven branches among lithium polysulfide intermediates(LiPS,e.g.,S_(8),Li_(2)S_(8),Li_(2)S_(6),Li_(2)S_(4)and Li_(2)S)[4].The obvious shuttle for soluble Lips across the cathode and anode leads to the battery capacity fading.Thus,it is necessary to decrease the accumulation of soluble Lips in the electrolyte through catalysts fastening the key conversion step from high-order polysulfides to insoluble Li_(2)S_(2)/Li_(2)S.Although some effort has been devoted to catalyze SRR,the complex mechanism remains unclear.To address this issue,Duan et al.tried to solve it based on nitrogen,sulfur,dualdoped holey graphene framework(N,S-HGF)electrocatalyst in Nature[5].展开更多
In this work,a new process for achieving the recovery of elemental sulfur by utilizing a fluidized catalytic cracking(FCC) riser reactor for SOxtreatment(FCC-DeSOx) is proposed.The process leverages the high temperatu...In this work,a new process for achieving the recovery of elemental sulfur by utilizing a fluidized catalytic cracking(FCC) riser reactor for SOxtreatment(FCC-DeSOx) is proposed.The process leverages the high temperatures and hydrocarbon concentrations in the FCC riser reactor to convert SOxinto H_(2)S.Subsequently,H_(2)S,along with the cracked gas,is processed downstream to produce sulfur.Thermodynamic analysis of the key reduction reactions in the FCC-DeSOxprocess revealed that complete conversion of SOxto H_(2)S is feasible in the dry gas(hydrogen-rich) prelift zone,as well as the upper and lower zones of the riser,upon achieving thermodynamic equilibrium.Experimental studies were conducted to replicate the conditions of these reaction zones using a low concentration of hydrogen gas as the reducing agent.Through process optimization,investigation of the minimum reaction time,and kinetic studies,the potential of this method for the complete reduction of SOxwas further confirmed.展开更多
Despite significant progress has been achieved regarding the shuttle-effect of lithium polysulfides,the suppressed specific capacity and retarded redox kinetics under high sulfur loading still threat the actual energy...Despite significant progress has been achieved regarding the shuttle-effect of lithium polysulfides,the suppressed specific capacity and retarded redox kinetics under high sulfur loading still threat the actual energy density and power density of lithium-sulfur batteries.In this study,a graham condenser-inspired carbon@WS_(2)host with coil-in-tube structure was designed and synthesized using anodic aluminum oxide(AAO)membrane with vertically aligned nanopores as template.The vertical array of carbon nanotubes with internal carbon coils not only leads to efficient charge transfer across through the thickness of the cathode,but also provides significant confinement to polysulfide diffusion towards both the lateral and longitudinal directions.Few-layer WS_(2)in the carbon coils perform a synergistic role in suppressing the shuttle-effect as well as boosting the cathodic kinetics.As a result,high specific capacity(1180 m Ah/g at 0.1 C)and long-cycling stability at 0.5 C for 500 cycles has been achieved at 3 mgS/cm^(2).Impressive areal capacity of 7.4 m Ah/cm^(2)has been demonstrated when the sulfur loading reaches 8.4 mg/cm^(2).The unique coil-in-tube structure developed in this work provides a new solution for high sulfur loading cathode towards practical lithium-sulfur batteries.展开更多
Pyrrhotite oxidation poses a big threat to water environment duo to its high potential for generating pollutants.Hydrogen peroxide,commonly found in natural water at micromolar concentrations,possesses much more aggre...Pyrrhotite oxidation poses a big threat to water environment duo to its high potential for generating pollutants.Hydrogen peroxide,commonly found in natural water at micromolar concentrations,possesses much more aggressive oxidation ability than oxygen and can complicate the pyrrhotite oxidation process.Here,the effects of micromolar H_(2)O_(2) on the biotic and abiotic oxidation of pyrrhotite were examined at pH 1.93 and 6.45,respectively.Pyrrhotite oxidation was much more severe in acidic solutions compared to near neutral solutions.Jarosite with a high Fe/S molar ratio was widely detected in the precipitate collected in acidic solutions,and the introduction of external H_(2)O_(2) influenced the crystallinity of jarosite.A layer of iron-deficient iron-sulfur oxide formed on the surface of pyrrhotite prevents its continuous oxidation,and the presence of Acidithiobacillus ferrooxidans enhanced this situation by promoting the release of Fe from the pyrrhotite.Additionally,the presence of external micromolar H_(2)O_(2) also determined the elemental state on pyrrhotite surface,as it found that the contribution of Fe^(3+)and S(S^(4+)and S^(6+))species on pyrrhotite surface increased with the increase of H_(2)O_(2) concentration in the solutions,especially in the presence of Acidithiobacillus ferrooxidans.展开更多
With the acceleration of industrialization,the pollution problem of sulfur dioxide(SO_(2))emitted from coal-fired power plants has become increasingly severe.Although wet flue gas desulfurization(FGD)technology can re...With the acceleration of industrialization,the pollution problem of sulfur dioxide(SO_(2))emitted from coal-fired power plants has become increasingly severe.Although wet flue gas desulfurization(FGD)technology can remove about 95%of SO_(2),its high energy consumption and the corrosion risk of downstream equipment caused by residual SO_(2)(500–3000 ppm)still need to be addressed[1].Previous porous materials(such as MOFs)achieve selective adsorption of SO_(2) through open metal sites,M–OH sites or functional organic groups,but the problem of CO_(2) co-adsorption limits their practical application[2].In recent years,hydrogen-bonded organic frameworks(HOFs)have emerged as a research hotspot due to their reversible hydrogen-bonding networks and flexible structures[3],but their stability under extreme conditions and efficient separation performance still need to be improved[4].展开更多
基金supported by“regional innovation mega project”program through the Korea Innovation Foundation funded by Ministry of Science and ICT(Project Number:2023-DD-UP-0026)the Energy Technology Evaluation and Planning(KETEP)and the Ministry of Trade,Industry&Energy(MOTIE)(No.RS-2024-00509401,RS-2023-00217581)“Regional Innovation Strategy(RIS)”through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(MOE)(2021RIS-001).
文摘High-performance lithium-ion batteries and sodium-ion batteries have been developed utilizing a hybrid anode material composed of zinc sulfide/sulfurized polyacrylonitrile.The in situ-generated zinc sulfide nanoparticles serve as catalytic agents,significantly enhancing conductivity,shortening diffusion paths,and accelerating reaction kinetics.Simultaneously,the sulfurized polyacrylonitrile fibers form a three-dimensional matrix that not only provides a continuous network for rapid electron transfer but also prevents zinc sulfide nanoparticle aggregation and mitigates volume changes during charge-discharge cycles.Moreover,the heterointerface structure at the junction of zinc sulfide nanoparticles and the sulfurized polyacrylonitrile matrix increases the availability of active sites and facilitates both ion adsorption and electron transfer.As an anode material for lithium-ion batteries,the zinc sulfide/sulfurized polyacrylonitrile hybrid demonstrates a high reversible capacity of 1178 mAh g^(-1)after 100 cycles at a current density of 0.2 A g^(-1),maintaining a capacity of 788 mAh g^(-1)after 200 cycles at 1 A g^(-1).It also exhibits excellent sodium storage capabilities,retaining a capacity of 625 mAh g^(-1)after 150 cycles at 0.2 A g^(-1).Furthermore,ex-situ X-ray photoelectron spectroscopy,X-ray diffraction,7Li solid-state magic angle spinning nuclear magnetic resonance,and in situ Raman are employed to investigate the reaction mechanisms of the zinc sulfide/sulfurized polyacrylonitrile hybrid anode,providing valuable insights that pave the way for the advancement of hybrid anode materials in lithium-ion batteries and sodium-ion batteries.
基金supported by the National Natural Science Foundation of China(62204074)the Hebei Natural Science Foundation(F2022201061,F2023201025)+2 种基金the Open bidding for selecting the best candidates of Baoding(2023chuang206)the High-level Talent Research Startup Project of Hebei University(521100221085)the Post-graduate's Innovation Fund Project of Hebei University(HBU2024BS030).
文摘Despite sulfurization offers the advantage of improving the photovoltaic performance in preparing Cu(In,Ga)Se2(CIGS)absorbers,deep level defects in the absorber and poor energy level alignment on the front surface are still main obstacles limiting the improvement of power co nversion efficiency(PCE)in sulfided CIGS solar cells.Herein,an in-situ Na doping strategy is proposed,in which the tailing effect of crystal growth is used to promote the sulfurization of CIGS absorbers.It is found that the grain growth is supported by Na incorporating due to the enrichment of NaSe_(x)near the upper surface.The high soluble Na during grain growth can not only suppress intrinsic In_(Cu) donor defects in the absorber,but also tailor S distribution in bulk and the band alignment at the heterojunction,which are both beneficial for the effective electron carriers.Meanwhile,the Na aggregation near the bottom of the absorber also contributes to the crystalline quality increasing and favorable ultra-thin MoSe_(2) formation at back contact,resulting in a reduced barrier height conducive to hole transport.PCE of the champion device is as high as 16.76%with a 28%increase.This research offers new insights into synthesizing CIGS solar cells and other chalcogenide solar cells with superior cell performance when using an intense sulfurization process.
基金supported by the National Natural Science Foundation of China(No.21805201)the NSFC-NRF China-Korea International Joint Research Project(No.51911540473)+1 种基金the Postdoctoral Research Foundation of China(No.2018T110544 and No.2017 M611899)the support by Suzhou Key Laboratory for Advanced Carbon Materials and Wearable Energy Technologies。
文摘Sulfurized polyacrylonitrile(SPAN)represents a unique class of cathode material for lithium sulfur(Li-S)batteries as it eradicates the polysulfides shuttling issue in carbonate-based electrolyte.However,due to the essential chemical S-linking and organic nature of SPAN,the active mass percentage and rate capability are two bottleneck issues preventing its ultimate deployment outside of laboratories.In the current work,aiming to endow both the charge conductivity and catalytic activity to SPAN for maximizing the redox kinetics of S conversion,a freestanding nanofibrous SPAN cathode embedding conductive CNTs and atomically dispersed Co centers is fabricated via multivariate electrospinning.While the CNTs enable dramatically enhancing the fiber conductivity and generating mesoscopic porosity for facilitating charge and mass transportation,the cross-linking of SPAN by Co-N_(4) S motifs creates extra charge conduction pathways and further serves as the catalytic active sites for expediting redox S conversion.As a result,an extraordinary Li-SPAN performance is achieved with a high specific capacity up to 1856 mAh g^(-1)@0.2 C,a superb rate capability up to 10 C,and an ultra-long battery life up to 1500 cycles@1 C.Consequently,our study here provides insights into the adoption of coordination chemistry to maximize the sulfur utilization by ensuring a more complete redox conversion from SPAN to Li2 S,and vice versa.
基金Funded by the National Natural Science Foundation of China （No. 51075366）
文摘The inclusion complex of fl-cyclodextrin （β-CD） and sulfurized isobutylene （T321） was prepared with a co-precipitation method. The tribological properties of the complex with different concentrations were investigated by a four-ball tester in the solution of polyethylene glycol-600 （PEG-600）. The experimental results suggest that the complex exhibits better anti-friction and anti-wear properties than fl-CD under different load conditions. The tribo-system shows the least friction coefficient when the concentration of the complex is 0.8%. During the friction process, the complex was decomposed into various molecular fragments and the T321 molecules were released onto the friction interface to provide effective lubrication. The XPS analytical results on the worn surfaces reveal that sulfide film formed by the released T321 plays a major role, and the iron alkoxide and carbon deposition films formed by the β-CD fragments have better anti-friction effect on the sulfide film surface. The interactions of different films result in the formation of a mixed boundary lubrication film.
基金supported by the National Natural Science Foundation of China(Grant nos.21773077,51632001,and 51532005)the Ministry of Science and Technology“973”program(Grant No.2015CB258400)the National Key R&D Program of China(2018YFB0905400)。
文摘Sulfurized polyacrylonitrile(SPAN)as a promising cathode material for lithium sulfur(Li-S)batteries has drawn increasing attention for its improved electrochemical performance in carbonate-based electrolyte.However,the relatively poor electronic and ionic conductivities of SPAN limit its high-rate and lowtemperature performances.In this work,a novel one-dimensional nanofiber SPAN(SFPAN)composite is developed as the cathode material for Li-S batteries.Benefitting from its one-dimensional nanostructure,the SFPAN composite cathode provides fast channels for the migration of ions and electronics,thus effectively improving its electrochemical performance at high rates and low temperature.As a result,the SFPAN maintains a high reversible specific capacity^1200 mAh g−1 after 400 cycles at 0.3 A g−1 and can deliver a high capacity of^850 mAh g−1 even at a high current density of 12.5 A g−1.What is more,the SFPAN can achieve a capacity of^800 mAh g−1 at 0℃and^1550 mAh g−1 at 60℃,thus providing a wider temperature range of applications.This work provides new perspectives on the cathode design for high-rate lithium-sulfur batteries.
基金Funded by the National Natural Science Foundation of China(No.51075366)
文摘The inclusion complex of β-cyclodextrin (β-CD) and sulfurized isobutylene (T321) was prepared with a co-precipitation method. The tribological properties of the complex with different concentrations were investigated by a four-ball tester in the solution of polyethylene glycol-600 (PEG-600). The experimental results suggest that the complex exhibits better anti-friction and anti-wear properties than β-CD under different load conditions. The tribo-system shows the least friction coefficient when the concentration of the complex is 0.8%. During the friction process, the complex was decomposed into various molecular fragments and the T321 molecules were released onto the friction interface to provide effective lubrication. The XPS analytical results on the worn surfaces reveal that sulfide film formed by the released T321 plays a major role, and the iron alkoxide and carbon deposition films formed by the β-CD fragments have better anti-friction effect on the sulfide film surface. The interactions of different films result in the formation of a mixed boundary lubrication film.
基金the Link Project of the National Natural Science Foundation of China and Guangdong Province(Grant no.U1301244)the National Natural Science Foundation of China(Grant nos.51573215,21506260)+2 种基金Guangdong Province Science&Technology Foundation(2011B050300008)Guangdong Natural Science Foundation(Grant nos.2014A030313159,2016A030313354)Guangzhou Scientific and Technological Planning Project(2014J4500002,201607010042)for financial support of this work
文摘Lithium–sulfur batteries have great potential for high energy applications due to their high capacities,low cost and eco-friendliness. However, the particularly rapid capacity decay owing to the dissolution and diffusion of polysulfide intermediate into the electrolyte still hamper their practical applications.And the reported preparation procedures to sulfur based cathode materials are often complex, and hence are rather difficult to produce at large scale. Here, we report a simple mechano-chemical sulfurization methodology in vacuum environment applying ball-milling method combined both the chemical and physical interaction for the one-pot synthesis of edge-sulfurized grapheme nanoplatelets with 3D porous foam structure as cathode materials. The optimal sample of 70%S–Gn Ps-48 h(ball-milled 48 h) obtains 13.2 wt% sulfur that chemically bonded onto the edge of Gn Ps. And the assembled batteries exhibit high initial discharge capacities of 1089 mAh/g at 0.1 C and 950 mAh/g at 0.5 C, and retain a stable discharge capacity of 776 mAh/g after 250 cycles at 0.5 C with a high Coulombic efficiency of over 98%. The excellent performance is mainly attributed to the mechano-chemical interaction between sulfur and grapheme nanoplatelets. This definitely triggers the currently extensive research in lithium–sulfur battery area.
基金supported by the National Natural Science Foundation of China(No.52172295)Basic Research Program of Jiangsu(No.BK20232013)+2 种基金Opening Project of Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory(No.ZHD202305)Postgraduate Research&Practice Innovation Program of Jiangsu Province(Nos.KYCX24_0571 and KYCX25_0602)Interdisciplinary Innovation Fund for Doctoral Students of Nanjing University of Aeronautics and Astronautics(No.KXKCXJJ202408)。
文摘The wide application of electromagnetic technology has led to increasingly frequent information transmission and communication interconnection.When the intensity of the disordered radiation of electromagnetic waves is too high,it will cause electromagnetic pollution and pose a huge threat to human health or the survival of other animals and plants.How to ingeniously design absorbing materials is the key to solving the problem.This paper proposes a new design concept.The Co-based zeolite imidazolite-structured material ZIF-67 was selected as the main body of the metal-organic frameworks(MOFs)template,and the dodecahedral structured ZIF-67 nanoparticles were prepared using the classic ion-ligand process.Subsequently,a dodecahedral NiCo-LDH nanoparticle precursor composed of NiCo bimetallic hydroxide nanosheets with hollow edges and interior was obtained based on the liquid-phase cationic etching process.On this basis,thioacetamide(TAA)was selected as the vulcanizing agent,and the ZIF-67-derived sulfide inheriting the micro-nano structure of the precursor was obtained through liquid-phase hydrothermal vulcanization.The vulcanization growth mechanism and electromagnetic wave absorption mechanism of the MOF_(S)-derived sulfide were deeply explored.
基金National Natural Science Foundation of China,Grant/Award Numbers:22109023,22179022,22209027Industry‐University‐Research Joint Innovation Project of Fujian Province,Grant/Award Number:2021H6006+3 种基金Youth Innovation Fund of Fujian Province,Grant/Award Numbers:2022J05046,2021J05043FuXia Quan National Independent Innovation Demonstration Zone Collaborative Innovation Platform Project of Fuzhou Science and Technology Bureau,Grant/Award Number:2022‐P‐027Award Program for Fujian Minjiang Scholar ProfessorshipTalent Fund Program of Fujian Normal University。
文摘Potassium-ion batteries(PIBs)have garnered significant attention as a promising alternative to commercial lithium-ion batteries(LIBs)due to abundant and cost-efficient potassium reserves.However,the large size of potassium ions and the resulting sluggish reaction kinetics present major obstacles to the widespread use of PIBs.Herein,we present a simple method to ingeniously encapsulate SnS_(2)nanoparticles within sulfurized polyacrylonitrile(SPAN)fibers(SnS_(2)@SPAN)for serving as a high-performance PIB anode.The large interlayer spacing of SnS_(2)provides a fast transport channel for potassium ions during charge–discharge cycles,while the one-dimensional SPAN skeleton offers massive binding sites and shortens the diffusion path for potassium ions,facilitating faster reaction kinetics.Additionally,the excellent ductility of SPAN can effectively accommodate the large volume changes that occur in SnS_(2)upon potassium-ion insertion,thereby enhancing the cyclic stability of SnS_(2).Benefiting from the above advantages,the SnS_(2)@SPAN composites exhibit impressive cyclability over 500 cycles at 4 A g−1,with a capacity retention rate close to 100%.This study provides an effective approach for stabilizing high-capacity PIB anode materials with large volume variations.
基金supported by the New Materials Research Key Program of Tianjin(Grant No.18ZXJMTG00110).
文摘Sulfurized polyacrylonitrile(SPAN)has emerged as an excellent cathode material for lithium–sulfur batteries(LiSBs),and it addresses the shuttle effect through a solid‒solid reaction.However,the actual sulfur loadings in SPAN often remain below 40 wt%.Due to the susceptibility of polysulfides-to-nucleophilic reactions with electrolytes,achieving physical encapsulation of elemental sulfur is a challenging task.In this study,a free-standing cathode material with a high sulfur/selenium(S/Se)loading of 55 wt%was fabricated by introducing SeS_(x) into the unique lotus root-like pores of porous SeS_(x)PAN nanofiber membranes by electrospinning and a two-step heat treatment.Insoluble compounds were formed due to nucleophilic interactions between lithium polyselenosulfides(LiSeSx)and the electrolyte,which potently blocked the existing lotus root-like pores and facilitated the creation of a thin cathode–electrolyte interphase on the fiber surface.This dual functionality of LiSeS_(x) safeguarded the active material embedded within the porous structure.The SeS_(15)PAN cathode exhibited remarkable cycling stability with almost no degradation after 200 cycles at 0.2 C,along with a high discharge capacity of 580 mAh/g.This approach presents a solution for addressing the insufficient sulfur content in SPAN.
基金The authors are indebted to the National Key Research and Development Program of China(No.2019YFE0122500)the National Natural Science Foundation of China(Nos.21878185 and 51772188)the Natural Science Foundation of Shanghai(No.21ZR1434800).
文摘Solid lithium-sulfur batteries(SLSBs)show potential for practical application due to their possibility for high energy density.However,SLSBs still face tough challenges such as the large interface impedance and lithium dendrite formation.Herein,a highperformance SLSB is demonstrated by using a fiber network reinforced Li_(6.75)La_(3)Zr_(1.75)Ta_(0.25)O_(12)(LLZTO)based composite solid electrolyte(CSE)in combination with sulfurized polyacrylonitrile(SPAN)cathode.The CSE consisting of an electrospun polyimide(PI)film,LLZTO ionically conducting filler and polyacrylonitrile(PAN)matrix,which is named as PI-PAN/LLZTO CSE,possesses high room-temperature ionic conductivity(2.75×10^(-4)S/cm),high Li^(+)migration number(tLi+)of 0.67 and good interfacial wettability.SPAN is utilized due to its unique electrochemical properties:reasonable electronic conductivity and no polysulfides shuttle effect.The CSE enables a highly stable Li plating/stripping cycle for over 600 h and good rate performance.Moreover,the assembled SLSB exhibits good cycle performance of accomplishing 120 cycles at 0.2 C with the capacity retention of 474 mAh/g,good rate properties and excellent long-term cycling stability with a high capacity retention of 86.49%from 15^(th)to 1,000^(th)cycles at 1.0 C.This work rationalizes our design concept and may guide the future development of SLSBs.
基金supported by the National Key Research and Development(R&D)Program of China(No.2021YFB2400300)the National Natural Science Foundation of China(No.22179083)+1 种基金Program of Shanghai Academic Research Leader(No.20XD1401900)Key-Area Research and Development Program of Guangdong Province(No.2019B090908001).
文摘Sulfurized polyacrylonitrile(S@pPAN)composite provides a conductive pathway for sulfur active material at the molecular level and has already become one of the most promising cathode materials in lithium-sulfur batteries because of its outstanding electrochemical performances via novel solid-solid conversion mechanism.Although there are a great number of researches on the S@pPAN composite material,the accurate structure of S@pPAN and its redox reaction mechanism during the charge-discharge process still have not been determined.The previous research and inferences about the structure of S@pPAN and its electrochemical reaction mechanism were summarized in this review,providing a reference for the future study of lithiumsulfur batteries.
基金Institute of Technology Research Fund Program for Young Scholars21C Innovation Laboratory Contemporary Amperex Technology Co.,Limited,Ninde, 352100, China (21C–OP-202314)。
文摘Lithium-sulfur (Li-S) batteries have gained great attention due to the high theoretical energy density and low cost,yet their further commercialization has been obstructed by the notorious shuttle effect and sluggish redox dynamics.Herein,we supply a strategy to optimize the electron structure of Ni_(2)P by concurrently introducing B-doped atoms and P vacancies in Ni_(2)P (Vp-B-Ni_(2)P),thereby enhancing the bidirectional sulfur conversion.The study indicates that the simultaneous introduction of B-doped atoms and P vacancies in Ni_(2)P causes the redistribution of electron around Ni atoms,bringing about the upward shift of d-band center of Ni atoms and effective d-p orbital hybridization between Ni atoms and sulfur species,thus strengthening the chemical anchoring for lithium polysulfides (LiPSs) as well as expediting the bidirectional conversion kinetics of sulfur species.Meanwhile,theoretical calculations reveal that the incorporation of B-doped atoms and P vacancies in Ni_(2)P selectively promotes Li2S dissolution and nucleation processes.Thus,the Li-S batteries with Vp-B-Ni_(2)P-separators present outstanding rate ability of 777 m A h g^(-1)at 5 C and high areal capacity of 8.03 mA h cm^(-2)under E/S of 5μL mg^(-1)and sulfur loading of 7.20 mg cm^(-2).This work elucidates that introducing heteroatom and vacancy in metal phosphide collaboratively regulates the electron structure to accelerate bidirectional sulfur conversion.
基金partially supported by National Natural Science Foundation of China(52172250)Institute of Process Engineering(IPE)Project for Frontier Basic Research(QYJC-2023-06)。
文摘The use of lithium-sulfur(Li-S)batteries is limited by sulfur redox reactions involving multi-phase transformations,especially at low-temperatures.To address this issue,we report a material(FCNS@NCFs)consisting of nitrogen-doped carbon fibers loaded with a ternary metal sulf-ide((Fe,Co,Ni)_(9)S_(8))for use as the sulfur host in Li-S batteries.This materi-al was prepared using transfer blot filter paper as the carbon precursor,thiourea as the source of nitrogen and sulfur,and FeCl_(3)·6H_(2)O,CoCl_(2)·6H_(2)O and NiCl_(2)·6H_(2)O as the metal ion sources.It was synthesized by an impreg-nation method followed by calcination.The nitrogen doping significantly in-creased the conductivity of the host,and the metal sulfides have excellent catalytic activities.Theoretical calculations,and adsorption and deposition experiments show that active sites on the surface of FCNS@NCFs selectively adsorb polysulfides,facilitate rapid adsorption and conversion,prevent cathode passivation and inhib-it the polysulfide shuttling.The FCNS@NCFs used as the sulfur host has excellent electrochemical properties.Its initial dis-charge capacity is 1639.0 mAh g^(−1) at 0.2 C and room temperature,and it remains a capacity of 1255.1 mAh g^(−1) after 100 cycles.At−20~C,it has an initial discharge capacity of 1578.5 mAh g^(−1) at 0.2 C,with a capacity of 867.5 mAh g^(−1) after 100 cycles.Its excellent performance at both ambient and low temperatures suggests a new way to produce high-performance low-temper-ature Li-S batteries.
基金National Key Research and Development Program of China(2021YFC2902301,2021YFC2902302)。
文摘A transformative beryllium metallurgy theory and method was proposed based on the low-temperature dissociation of hydrofluoric acid and purification by exploiting the large difference of fluoride solubility.Hydrofluoric acid can quickly dissociate berylum ore powder directly at low or room temperature with more than 99%dissociation rate.The solubility of AlF_(3),FeF_(3) CrF_(3) and MgF_(2),is low.Coupled with common ion effect,99.9%-purity beryllium products can be prepared without chemical purification.For high-purity beryllium products of grade 4N or higher,they can be prepared through the superior property that the pH intervals of iron,chromium,and other hydroxide precipitates are distinctly different from those corresponding to Be(OH)_(2),precipitates.This new method can be used to prepare most of the beryllium products that are prepared by modern beryllium metallurgy.
文摘Lithium metal batteries(LMBs)have attracted great intention due to the high energy density[1].Among various battery technologies,lithium-sulfur(Li-S)batteries are also very unique but important due to its high energy density,low cost and available sources[2].Although Li-s batteries exhibit high energy density,the cycling life is poor,especially for large-capacity pouch cells[3].The cycling performance of Li-s batteries is crucially determined by 16-electron complex sulfur reduction reaction(SRR)from S_(8)molecules to Li_(2)S,solid,which involves the multiple potential interwoven branches among lithium polysulfide intermediates(LiPS,e.g.,S_(8),Li_(2)S_(8),Li_(2)S_(6),Li_(2)S_(4)and Li_(2)S)[4].The obvious shuttle for soluble Lips across the cathode and anode leads to the battery capacity fading.Thus,it is necessary to decrease the accumulation of soluble Lips in the electrolyte through catalysts fastening the key conversion step from high-order polysulfides to insoluble Li_(2)S_(2)/Li_(2)S.Although some effort has been devoted to catalyze SRR,the complex mechanism remains unclear.To address this issue,Duan et al.tried to solve it based on nitrogen,sulfur,dualdoped holey graphene framework(N,S-HGF)electrocatalyst in Nature[5].
基金supported by General Program of National Natural Science Foundation of China (22178385)。
文摘In this work,a new process for achieving the recovery of elemental sulfur by utilizing a fluidized catalytic cracking(FCC) riser reactor for SOxtreatment(FCC-DeSOx) is proposed.The process leverages the high temperatures and hydrocarbon concentrations in the FCC riser reactor to convert SOxinto H_(2)S.Subsequently,H_(2)S,along with the cracked gas,is processed downstream to produce sulfur.Thermodynamic analysis of the key reduction reactions in the FCC-DeSOxprocess revealed that complete conversion of SOxto H_(2)S is feasible in the dry gas(hydrogen-rich) prelift zone,as well as the upper and lower zones of the riser,upon achieving thermodynamic equilibrium.Experimental studies were conducted to replicate the conditions of these reaction zones using a low concentration of hydrogen gas as the reducing agent.Through process optimization,investigation of the minimum reaction time,and kinetic studies,the potential of this method for the complete reduction of SOxwas further confirmed.
基金the National Natural Science Foundation of China(Nos.22075027,52003030)Starting Grant from Beijing Institute of Technology and financial support from the State Key Laboratory of Explosion Science and Safety Protection(Nos.YBKT2106,YBKT23-05)Beijing Institute of Technology Research Fund Program for Young Scholars。
文摘Despite significant progress has been achieved regarding the shuttle-effect of lithium polysulfides,the suppressed specific capacity and retarded redox kinetics under high sulfur loading still threat the actual energy density and power density of lithium-sulfur batteries.In this study,a graham condenser-inspired carbon@WS_(2)host with coil-in-tube structure was designed and synthesized using anodic aluminum oxide(AAO)membrane with vertically aligned nanopores as template.The vertical array of carbon nanotubes with internal carbon coils not only leads to efficient charge transfer across through the thickness of the cathode,but also provides significant confinement to polysulfide diffusion towards both the lateral and longitudinal directions.Few-layer WS_(2)in the carbon coils perform a synergistic role in suppressing the shuttle-effect as well as boosting the cathodic kinetics.As a result,high specific capacity(1180 m Ah/g at 0.1 C)and long-cycling stability at 0.5 C for 500 cycles has been achieved at 3 mgS/cm^(2).Impressive areal capacity of 7.4 m Ah/cm^(2)has been demonstrated when the sulfur loading reaches 8.4 mg/cm^(2).The unique coil-in-tube structure developed in this work provides a new solution for high sulfur loading cathode towards practical lithium-sulfur batteries.
基金supported by the National Key Research and Development Program of China(No.2022YFC3203301)the Natural Science Foundation of China(No.41406098).
文摘Pyrrhotite oxidation poses a big threat to water environment duo to its high potential for generating pollutants.Hydrogen peroxide,commonly found in natural water at micromolar concentrations,possesses much more aggressive oxidation ability than oxygen and can complicate the pyrrhotite oxidation process.Here,the effects of micromolar H_(2)O_(2) on the biotic and abiotic oxidation of pyrrhotite were examined at pH 1.93 and 6.45,respectively.Pyrrhotite oxidation was much more severe in acidic solutions compared to near neutral solutions.Jarosite with a high Fe/S molar ratio was widely detected in the precipitate collected in acidic solutions,and the introduction of external H_(2)O_(2) influenced the crystallinity of jarosite.A layer of iron-deficient iron-sulfur oxide formed on the surface of pyrrhotite prevents its continuous oxidation,and the presence of Acidithiobacillus ferrooxidans enhanced this situation by promoting the release of Fe from the pyrrhotite.Additionally,the presence of external micromolar H_(2)O_(2) also determined the elemental state on pyrrhotite surface,as it found that the contribution of Fe^(3+)and S(S^(4+)and S^(6+))species on pyrrhotite surface increased with the increase of H_(2)O_(2) concentration in the solutions,especially in the presence of Acidithiobacillus ferrooxidans.
基金the support of the National Natural Science Foundation of China(Nos.22205207 and 22378369).
文摘With the acceleration of industrialization,the pollution problem of sulfur dioxide(SO_(2))emitted from coal-fired power plants has become increasingly severe.Although wet flue gas desulfurization(FGD)technology can remove about 95%of SO_(2),its high energy consumption and the corrosion risk of downstream equipment caused by residual SO_(2)(500–3000 ppm)still need to be addressed[1].Previous porous materials(such as MOFs)achieve selective adsorption of SO_(2) through open metal sites,M–OH sites or functional organic groups,but the problem of CO_(2) co-adsorption limits their practical application[2].In recent years,hydrogen-bonded organic frameworks(HOFs)have emerged as a research hotspot due to their reversible hydrogen-bonding networks and flexible structures[3],but their stability under extreme conditions and efficient separation performance still need to be improved[4].
