期刊文献+
共找到5,242篇文章
< 1 2 250 >
每页显示 20 50 100
All‑Covalent Organic Framework Nanofilms Assembled Lithium‑Ion Capacitor to Solve the Imbalanced Charge Storage Kinetics 被引量:2
1
作者 Xiaoyang Xu Jia Zhang +6 位作者 Zihao Zhang Guandan Lu Wei Cao Ning Wang Yunmeng Xia Qingliang Feng Shanlin Qiao 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第6期246-260,共15页
Free-standing covalent organic framework(COFs)nanofilms exhibit a remarkable ability to rapidly intercalate/de-intercalate Li^(+) in lithium-ion batteries,while simultaneously exposing affluent active sites in superca... Free-standing covalent organic framework(COFs)nanofilms exhibit a remarkable ability to rapidly intercalate/de-intercalate Li^(+) in lithium-ion batteries,while simultaneously exposing affluent active sites in supercapacitors.The development of these nanofilms offers a promising solution to address the persistent challenge of imbalanced charge storage kinetics between battery-type anode and capacitor-type cathode in lithium-ion capacitors(LICs).Herein,for the first time,custom-made COFBTMB-TP and COFTAPB-BPY nanofilms are synthesized as the anode and cathode,respectively,for an all-COF nanofilm-structured LIC.The COFBTMB-TP nanofilm with strong electronegative–CF3 groups enables tuning the partial electron cloud density for Li^(+) migration to ensure the rapid anode kinetic process.The thickness-regulated cathodic COFTAPB-BPY nanofilm can fit the anodic COF nanofilm in the capacity.Due to the aligned 1D channel,2D aromatic skeleton and accessible active sites of COF nanofilms,the whole COFTAPB-BPY//COFBTMB-TP LIC demonstrates a high energy density of 318 mWh cm^(−3) at a high-power density of 6 W cm^(−3),excellent rate capability,good cycle stability with the capacity retention rate of 77%after 5000-cycle.The COFTAPB-BPY//COFBTMB-TP LIC represents a new benchmark for currently reported film-type LICs and even film-type supercapacitors.After being comprehensively explored via ex situ XPS,7Li solid-state NMR analyses,and DFT calculation,it is found that the COFBTMB-TP nanofilm facilitates the reversible conversion of semi-ionic to ionic C–F bonds during lithium storage.COFBTMB-TP exhibits a strong interaction with Li^(+) due to the C–F,C=O,and C–N bonds,facilitating Li^(+) desolation and absorption from the electrolyte.This work addresses the challenge of imbalanced charge storage kinetics and capacity between the anode and cathode and also pave the way for future miniaturized and wearable LIC devices. 展开更多
关键词 Covalent organic frameworks Lithium-ion capacitor Charge storage kinetic
下载PDF
“Buckets effect”in the kinetics of electrocatalytic reactions 被引量:1
2
作者 Haowen Cui Yan-Xia Chen 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期388-396,I0010,共10页
In this study,we systematically investigated the effect of proton concentration on the kinetics of the oxygen reduction reaction(ORR)on Pt(111)in acidic solutions.Experimental results demonstrate a rectangular hyperbo... In this study,we systematically investigated the effect of proton concentration on the kinetics of the oxygen reduction reaction(ORR)on Pt(111)in acidic solutions.Experimental results demonstrate a rectangular hyperbolic relationship,i.e.,the ORR current excluding the effect of other variables increases with proton concentration and then tends to a constant value.We consider that this is caused by the limitation of ORR kinetics by the trace oxygen concentration in the solution,which determines the upper limit of ORR kinetics.A model of effective concentration is further proposed for rectangular hyperbolic relationships:when the reactant concentration is high enough to reach a critical saturation concentration,the effective reactant concentration will become a constant value.This could be due to the limited concentration of a certain reactant for reactions involving more than one reactant or the limited number of active sites available on the catalyst.Our study provides new insights into the kinetics of electrocatalytic reactions,and it is important for the proper evaluation of catalyst activity and the study of structureperformance relationships. 展开更多
关键词 Oxygen reduction reaction kinetics Zero order Rectangular hyperbolic relationship pH effect
下载PDF
Dual-single-atoms of Pt-Co boost sulfur redox kinetics for ultrafast Li-S batteries 被引量:1
3
作者 Hanyan Wu Xuejie Gao +7 位作者 Xinyang Chen Weihan Li Junjie Li Lei Zhang Yang Zhao Ming Jiang Runcang Sun Xueliang Sun 《Carbon Energy》 SCIE EI CAS CSCD 2024年第3期53-63,共11页
Applications of lithium-sulfur(Li-S)batteries are still limited by the sluggish conversion kinetics from polysulfide to Li_(2)S.Although various single-atom catalysts are available for improving the conversion kinetic... Applications of lithium-sulfur(Li-S)batteries are still limited by the sluggish conversion kinetics from polysulfide to Li_(2)S.Although various single-atom catalysts are available for improving the conversion kinetics,the sulfur redox kinetics for Li-S batteries is still not ultrafast.Herein,in this work,a catalyst with dual-single-atom Pt-Co embedded in N-doped carbon nanotubes(Pt&Co@NCNT)was proposed by the atomic layer deposition method to suppress the shuttle effect and synergistically improve the interconversion kinetics from polysulfides to Li_(2)S.The X-ray absorption near edge curves indicated the reversible conversion of Li_(2)Sx on the S/Pt&Co@NCNT electrode.Meanwhile,density functional theory demonstrated that the Pt&Co@NCNT promoted the free energy of the phase transition of sulfur species and reduced the oxidative decomposition energy of Li_(2)S.As a result,the batteries assembled with S/Pt&Co@NCNT electrodes exhibited a high capacity retention of 80%at 100 cycles at a current density of 1.3 mA cm^(−2)(S loading:2.5 mg cm^(−2)).More importantly,an excellent rate performance was achieved with a high capacity of 822.1 mAh g^(−1) at a high current density of 12.7 mA cm^(−2).This work opens a new direction to boost the sulfur redox kinetics for ultrafast Li-S batteries. 展开更多
关键词 DFT calculation dual-single-atoms of Pt-Co fast Li-sulfur batteries sulfur redox kinetics XANES analysis
下载PDF
Recent progress in thermodynamic and kinetics modification of magnesium hydride hydrogen storage materials 被引量:1
4
作者 Yafei Liu Yusang Guo +3 位作者 Yaru Jiang Lizhuang Feng Yu Sun Yijing Wang 《Materials Reports(Energy)》 EI 2024年第1期3-22,共20页
Hydrogen energy has emerged as a pivotal solution to address the global energy crisis and pave the way for a cleaner,low-carbon,secure,and efficient modern energy system.A key imperative in the utilization of hydrogen... Hydrogen energy has emerged as a pivotal solution to address the global energy crisis and pave the way for a cleaner,low-carbon,secure,and efficient modern energy system.A key imperative in the utilization of hydrogen energy lies in the development of high-performance hydrogen storage materials.Magnesium-based hydrogen storage materials exhibit remarkable advantages,including high hydrogen storage density,cost-effectiveness,and abundant magnesium resources,making them highly promising for the hydrogen energy sector.Nonetheless,practical applications of magnesium hydride for hydrogen storage face significant challenges,primarily due to their slow kinetics and stable thermodynamic properties.Herein,we briefly summarize the thermodynamic and kinetic properties of MgH2,encompassing strategies such as alloying,nanoscaling,catalyst doping,and composite system construction to enhance its hydrogen storage performance.Notably,nanoscaling and catalyst doping have emerged as more effective modification strategies.The discussion focuses on the thermodynamic changes induced by nanoscaling and the kinetic enhancements resulting from catalyst doping.Particular emphasis lies in the synergistic improvement strategy of incorporating nanocatalysts with confinement materials,and we revisit typical works on the multi-strategy optimization of MgH2.In conclusion,we conduct an analysis of outstanding challenges and issues,followed by presenting future research and development prospects for MgH2 as hydrogen storage materials. 展开更多
关键词 Magnesium hydride Thermodynamics and kinetics Catalyst doping NANOSTRUCTURES Hydrogenation and dehydrogenation
下载PDF
Kinetics and mechanism of the low-energy β-a phase transition of the second kind in 2,4-dinitroanisole
5
作者 Aleksandr V.Stankevich Nikolay A.Rasputin +3 位作者 Anisa KhRudina Gennady L.Rusinov Vera I.Filyakova Valery N.Charushin 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第10期210-224,共15页
In this work, comprehensive studies of 2,4-dinitroanisole(2,4DNAN) were carried out using powder thermorentgenography of the internal standard. The time of the complete polymorphic transition in the solid phase β→a ... In this work, comprehensive studies of 2,4-dinitroanisole(2,4DNAN) were carried out using powder thermorentgenography of the internal standard. The time of the complete polymorphic transition in the solid phase β→a in 2,4DNAN under various combinations of conditions has been determined. It has been established that, regardless of the season of manufacture of the substance, when it is stored for 8-9months, with a change in ambient temperature from minus 30℃ to plus 30℃, a complete polymorphic transition β→a occurs. When stored in conditions below minus 5℃, polymorphic transition does not occur. When stored in conditions above plus 30℃ in a closed container, polymorphic transition occurs within 3 weeks. The polymorphic transition is accompanied by a decrease in density by 1.3%-1.5% and an increase in melting temperature by 10-12℃, depending on the degree of purity of the starting substance. The activation energy of the molecular rearrangement was 68-70 k J/mol(16.5 ± 3 kcal/mol). The mechanism of polymorphic transition has been evaluated, which is presumably based on internal homodiffusion and energy transfer to the surface of the mass of powder particles and the product. The average activation energy of the polymorphic transition process was 110 ± 6.2 k J/mol(26.2 kcal/mol). In an open container, reactions proceed by a homogeneous mechanism, and in a closed container by a heterogeneous mechanism involving the gas phase. 展开更多
关键词 Energetic materials Melt-castable 2 4-Dinitroanisole Polymorphic transition kinetics Mechanism Homodiffusion SUBLIMATION
下载PDF
Continuous synthesis of N,N-dicyanoethylaniline in microreactors:Reaction kinetics and process intensification
6
作者 Pengcheng Lu Yaoyao Li +5 位作者 Jianjun Zhang Yuchao Zhao Qingqiang Wang Ying Chen Nan Jin Xiugang Yu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第8期95-105,共11页
Cyanoethylation of phenylamine is one of the important steps for the production of dicyanoethyl-based disperse dyes.However,the exothermic nature of this reaction and the inherent instability of intermittent dynamic o... Cyanoethylation of phenylamine is one of the important steps for the production of dicyanoethyl-based disperse dyes.However,the exothermic nature of this reaction and the inherent instability of intermittent dynamic operation pose challenges in achieving both high safety and reaction efficiency.In this study,a continuous cyanoethylation of phenylamine for synthesizing N,N-dicyanoethylaniline in a microreactor system has been developed.By optimizing the reaction conditions,the reaction time was significantly reduced from over 2 h in batch operation to approximately 14 min in the microreactor,while high conversion and selectivity were maintained.Based on the reaction network constructed,the reaction kinetics was established,and the kinetic parameters were then determined.These findings provide valuable insights into a controllable cyanoethylation reaction,which would be helpful for the design of efficient processes and optimization of reactors. 展开更多
关键词 Cyanoethylation MICROREACTOR kinetics N N-dicyanoethylaniline Optimization Safety
下载PDF
Boosted Lithium-Ion Transport Kinetics in n-Type Siloxene Anodes Enabled by Selective Nucleophilic Substitution of Phosphorus
7
作者 Se In Kim Woong-Ju Kim +1 位作者 Jin Gu Kang Dong-Wan Kim 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第10期618-637,共20页
Doped two-dimensional(2D)materials hold significant promise for advancing many technologies,such as microelectronics,optoelectronics,and energy storage.Herein,n-type 2D oxidized Si nanosheets,namely n-type siloxene(n-... Doped two-dimensional(2D)materials hold significant promise for advancing many technologies,such as microelectronics,optoelectronics,and energy storage.Herein,n-type 2D oxidized Si nanosheets,namely n-type siloxene(n-SX),are employed as Li-ion battery anodes.Via thermal evaporation of sodium hypophosphite at 275℃,P atoms are effectively incorporated into siloxene(SX)without compromising its 2D layered morphology and unique Kautsky-type crystal structure.Further,selective nucleophilic substitution occurs,with only Si atoms being replaced by P atoms in the O_(3)≡Si-H tetrahedra.The resulting n-SX possesses two delocalized electrons arising from the presence of two electron donor types:(i)P atoms residing in Si sites and(ii)H vacancies.The doping concentrations are varied by controlling the amount of precursors or their mean free paths.Even at 2000 mA g^(-1),the n-SX electrode with the optimized doping concentration(6.7×10^(19) atoms cm^(-3))delivers a capacity of 594 mAh g^(-1) with a 73%capacity retention after 500 cycles.These improvements originate from the enhanced kinetics of charge transport processes,including electronic conduction,charge transfer,and solid-state diffusion.The approach proposed herein offers an unprecedented route for engineering SX anodes to boost Li-ion storage. 展开更多
关键词 Li-ion battery Two-dimensional N-type siloxene Doping mechanism kinetics
下载PDF
Tuning the crystallinity of titanium nitride on copper-embedded carbon nanofiber interlayers for accelerated electrochemical kinetics in lithium-sulfur batteries
8
作者 Yinyu Xiang Liqiang Lu +4 位作者 Feng Yan Debarun Sengupta Petra Rudolf Ajay Giri Prakash Kottapalli Yutao Pei 《Carbon Energy》 SCIE EI CAS CSCD 2024年第6期40-55,共16页
The development of lithium-sulfur(Li-S)batteries is hindered by the disadvantages of shuttling of polysulfides and the sluggish redox kinetics of the conversion of sulfur species during discharge and charge.Herein,the... The development of lithium-sulfur(Li-S)batteries is hindered by the disadvantages of shuttling of polysulfides and the sluggish redox kinetics of the conversion of sulfur species during discharge and charge.Herein,the crystallinities of a titanium nitride(TiN)film on copper-embedded carbon nanofibers(Cu-CNFs)are regulated and the nanofibers are used as interlayers to resolve the aforementioned crucial issues.A low-crystalline TiN-coated Cu-CNF(L-TiN-Cu-CNF)interlayer is compared with its highly crystalline counterpart(H-TiN-Cu-CNFs).It is demonstrated that the L-TiN coating not only strengthens the chemical adsorption toward polysulfides but also greatly accelerates the electrochemical conversion of polysulfides.Due to robust carbon frameworks and enhanced kinetics,impressive highrate performance at 2 C(913 mAh g^(-1)based on sulfur)as well as remarkable cyclic stability up to 300 cycles(626 mAh g^(-1))with capacity retention of 46.5%is realized for L-TiN-Cu-CNF interlayer-configured Li-S batteries.Even under high loading(3.8 mg cm^(-2))of sulfur and relatively lean electrolyte(10μL electrolyte per milligram sulfur)conditions,the Li-S battery equipped with L-TiN-Cu-CNF interlayers delivers a high capacity of 1144 mAh g^(-1)with cathodic capacity of 4.25 mAh cm^(-2)at 0.1 C,providing a potential pathway toward the design of multifunctional interlayers for highly efficient Li-S batteries. 展开更多
关键词 CRYSTALLINITY electrochemical kinetics INTERLAYER lithium-sulfur batteries titanium nitride
下载PDF
Geochemical modeling to aid experimental design for multiple isotope tracer studies of coupled dissolution and precipitation reaction kinetics
9
作者 Mingkun Chen Peng Lu +1 位作者 Yongchen Song Chen Zhu 《Acta Geochimica》 EI CAS CSCD 2024年第1期1-15,共15页
It is a challenge to make thorough but efficient experimental designs for the coupled mineral dissolution and precipitation studies in a multi-mineral system, because it is difficult to speculate the best experimental... It is a challenge to make thorough but efficient experimental designs for the coupled mineral dissolution and precipitation studies in a multi-mineral system, because it is difficult to speculate the best experimental duration, optimal sampling schedule, effects of different experimental conditions, and how to maximize the experimental outputs prior to the actual experiments. Geochemical modeling is an efficient and effective tool to assist the experimental design by virtually running all scenarios of interest for the studied system and predicting the experimental outcomes. Here we demonstrated an example of geochemical modeling assisted experimental design of coupled labradorite dissolution and calcite and clayey mineral precipitation using multiple isotope tracers. In this study, labradorite(plagioclase) was chosen as the reactant because it is both a major component and one of the most reactive minerals in basalt. Following our isotope doping studies of single minerals in the last ten years, initial solutions in the simulations were doped withmultiple isotopes(e.g., Ca and Si). Geochemical modeling results show that the use of isotope tracers gives us orders of magnitude more sensitivity than the conventional method based on concentrations and allows us to decouple dissolution and precipitation reactions at near-equilibrium condition. The simulations suggest that the precise unidirectional dissolution rates can inform us which rate laws plagioclase dissolution has followed. Calcite precipitation occurred at near-equilibrium and the multiple isotope tracer experiments would provide near-equilibrium precipitation rates, which was a challenge for the conventional concentration-based experiments. In addition, whether the precipitation of clayey phases is the rate-limiting step in some multi-mineral systems will be revealed. Overall, the modeling results of multimineral reaction kinetics will improve the understanding of the coupled dissolution–precipitation in the multi-mineral systems and the quality of geochemical modeling prediction of CO_(2) removal and storage efficacy in the basalt systems. 展开更多
关键词 kinetics FELDSPAR Isotope doping Near-equilibrium CO_(2)sequestration BASALT
下载PDF
Co-pyrolysis of Sewage Sludge with Distillation Residue: Kinetics Analysis via Iso-conversional Methods
10
作者 ZHOU Shangqun ZHAO Qinglin +1 位作者 YU Tian YAO Xiaojie 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第5期1188-1198,共11页
This study explored the synergistic interaction of sewage sludge(SS)and distillation residue(DR)during co-pyrolysis for the optimized treatment of sewage sludge in cement kiln systems,utilizing thermogravimetric analy... This study explored the synergistic interaction of sewage sludge(SS)and distillation residue(DR)during co-pyrolysis for the optimized treatment of sewage sludge in cement kiln systems,utilizing thermogravimetric analysis(TGA)and thermogravimetric analysis with mass spectrometry(TGA-MS).The results reveal the coexisting synergistic and antagonistic effects in the co-pyrolysis of SS/DR.The synergistic effect arises from hydrogen free radicals in SS and catalytic components in ash fractions,while the antagonistic effect is mainly due to the melting of DR on the surface of SS particles during pyrolysis and the reaction of SS ash with alkali metals to form inert substances.SS/DR co-pyrolysis reduces the yielding of coke and gas while increasing tar production.This study will promote the reduction,recycling,and harmless treatment of hazardous solid waste. 展开更多
关键词 sewage sludge CO-PYROLYSIS distillation residue kinetics evolved gas analysis
下载PDF
Description of martensitic transformation kinetics in Fe-C-X(X = Ni,Cr,Mn,Si) system by a modified model
11
作者 Xiyuan Geng Hongcan Chen +3 位作者 Jingjing Wang Yu Zhang Qun Luo Qian Li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第5期1026-1036,共11页
Controlling the content of athermal martensite and retained austenite is important to improving the mechanical properties of high-strength steels,but a mechanism for the accurate description of martensitic transformat... Controlling the content of athermal martensite and retained austenite is important to improving the mechanical properties of high-strength steels,but a mechanism for the accurate description of martensitic transformation during the cooling process must be addressed.At present,frequently used semi-empirical kinetics models suffer from huge errors at the beginning of transformation,and most of them fail to exhibit the sigmoidal shape characteristic of transformation curves.To describe the martensitic transformation process accurately,based on the Magee model,we introduced the changes in the nucleation activation energy of martensite with temperature,which led to the varying nucleation rates of this model during martensitic transformation.According to the calculation results,the relative error of the modified model for the martensitic transformation kinetics curves of Fe-C-X(X = Ni,Cr,Mn,Si) alloys reached 9.5% compared with those measured via the thermal expansion method.The relative error was approximately reduced by two-thirds compared with that of the Magee model.The incorporation of nucleation activation energy into the kinetics model contributes to the improvement of its precision. 展开更多
关键词 Fe-C-X system martensitic transformation kinetics curve semi-empirical model nucleation activation energy
下载PDF
Kinetics insights into size effects of carbon nanotubes'growth and their supported platinum catalysts for 4,6-dinitroresorcinol hydrogenation
12
作者 Yan Zhang Xiangxue Zhang +6 位作者 Keng Sang Wenyao Chen Gang Qian Jing Zhang Xuezhi Duan Xinggui Zhou Weikang Yuan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第8期133-140,共8页
Size effects are a well-documented phenomenon in heterogeneous catalysis,typically attributed to alterations in geometric and electronic properties.In this study,we investigate the influence of catalyst size in the pr... Size effects are a well-documented phenomenon in heterogeneous catalysis,typically attributed to alterations in geometric and electronic properties.In this study,we investigate the influence of catalyst size in the preparation of carbon nanotube(CNT)and the hydrogenation of 4,6-dinitroresorcinol(DNR)using Fe_(2)O_(3)and Pt catalysts,respectively.Various Fe_(2)O_(3)/Al_(2)O_(3)catalysts were synthesized for CNT growth through catalytic chemical vapor deposition.Our findings reveal a significant influence of Fe_(2)O_(3)nanoparticle size on the structure and yield of CNT.Specifically,CNT produced with Fe_(2)O_(3)/Al_(2)O_(3)containing 28%(mass)Fe loading exhibits abundant surface defects,an increased area for metal-particle immobilization,and a high carbon yield.This makes it a promising candidate for DNR hydrogenation.Utilizing this catalyst support,we further investigate the size effects of Pt nanoparticles on DNR hydrogenation.Larger Pt catalysts demonstrate a preference for 4,6-diaminoresorcinol generation at(100)sites,whereas smaller Pt catalysts are more susceptible to electronic properties.The kinetics insights obtained from this study have the potential to pave the way for the development of more efficient catalysts for both CNT synthesis and DNR hydrogenation. 展开更多
关键词 kinetics Size effects Catalytic hydrogenation Active site
下载PDF
Modulation of Electronic States in Bimetallic-doped Nitrogen-Carbon Based Nanoparticles for Enhanced Oxygen Reduction Kinetics
13
作者 Chen Gong Chenyu Yang +2 位作者 Wanlin Zhou Hui Su Qinghua Liu 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2024年第4期513-521,I0042-I0060,I0094,共29页
Controlling the local electronic structure of active ingredients to improve the adsorption desorption characteristics of oxygen-containing intermediates over the electrochemical liquid-solid interfaces is a critical c... Controlling the local electronic structure of active ingredients to improve the adsorption desorption characteristics of oxygen-containing intermediates over the electrochemical liquid-solid interfaces is a critical challenge in the field of oxygen reduction reaction(ORR)catalysis.Here,we offer a simple approach for modulating the electronic states of metal nanocrystals by bimetal co-doping into carbon-nitrogen substrate,allowing us to modulate the electronic structure of catalytic active centers.To test our strategy,we designed a typical bimetallic nanoparticle catalyst(Fe-Co NP/NC)to flexibly alter the reaction kinetics of ORR.Our results from synchrotron Xray absorption spectroscopy and X-ray photoelectron spectroscopy showed that the co-doping of iron and cobalt could optimize the intrinsic charge distribution of Fe-Co NP/NC catalyst,promoting the oxygen reduction kinetics and ultimately achieving remarkable ORR activity.Consequently,the carefully designed Fe-Co NP/NC exhibits an ultra-high kinetic current density at the operating voltage(71.94 mA/cm^(2)at 0.80 V),and the half-wave potential achieves 0.915 V,which is obviously better than that of the corresponding controls including Fe NP/NC,Co NP/NC.Our findings provide a unique perspective for optimizing the electronic structure of active centers to achieve higher ORR catalytic activity and faster kinetics. 展开更多
关键词 Oxygen reduction reaction Reaction kinetics Electronic state modulation CODOPING ELECTROCATALYSIS
下载PDF
Improving hydrogen storage thermodynamics and kinetics of Ce-Mg-Ni-based alloy by mechanical milling with TiF_(3)
14
作者 Hongwei Shang Wei Zhang +4 位作者 Xin Wei Yaqin Li Zeming Yuan Jun Li Yanghuan Zhang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第4期1593-1607,共15页
Mg-based hydrides are too stable and the kinetics of hydrogen absorption and desorption is not satisfactory.An efficient way to improve these shortcomings is to employ reactive ball milling to synthesize the nanocompo... Mg-based hydrides are too stable and the kinetics of hydrogen absorption and desorption is not satisfactory.An efficient way to improve these shortcomings is to employ reactive ball milling to synthesize the nanocomposite materials of Mg and additives.In this experiment,TiF_(3)was selected as an additive,and the mechanical milling method was employed to prepare the experimental alloys.The alloys used in this experiment were the as-cast Ce_(5)Mg_(85)Ni_(10),as-milled Ce_(5)Mg_(85)Ni_(10)and Ce_(5)Mg_(85)Ni_(10)+3 wt.%TiF3.The phase transformation,structural evolution,isothermal and non-isothermal hydrogenation and dehydrogenation performances of the alloys were inspected by XRD,SEM,TEM,Sievert apparatus,DSC and TGA.It revealed that nanocrystalline appeared in the as-milled samples.Compared with the as-cast alloy,ball milling made the particle dimension and grain size decrease dramatically and the defect density increase significantly.The addition of TiF_(3)made the surface of ball milling alloy particles markedly coarser and more irregular.Ball milling and adding TiF_(3)distinctly improved the activation and kinetics of the alloys.Moreover,ball milling along with TiF_(3)can decrease the onset dehydrogenation temperature of Mg-based hydrides and slightly ameliorate their thermodynamics. 展开更多
关键词 Mg-based hydrides TiF_(3) Ball milling THERMODYNAMICS kinetics
下载PDF
Mitigated reaction kinetics between lithium metal anodes and electrolytes by alloying lithium metal with low-content magnesium
15
作者 Yang-Yang Wang Ya-Nan Wang +9 位作者 Nan Yao Shu-Yu Sun Xiao-Qing Ding Chen-Xi Bi Qian-Kui Zhang Zhao Zheng Cheng-Bin Jin Bo-Quan Li Xue-Qiang Zhang Jia-Qi Huang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期644-650,I0014,共8页
Lithium(Li)metal is regarded as a promising anode candidate for high-energy-density rechargeable batteries.Nevertheless,Li metal is highly reactive against electrolytes,leading to rapid decay of active Li metal reserv... Lithium(Li)metal is regarded as a promising anode candidate for high-energy-density rechargeable batteries.Nevertheless,Li metal is highly reactive against electrolytes,leading to rapid decay of active Li metal reservoir.Here,alloying Li metal with low-content magnesium(Mg)is proposed to mitigate the reaction kinetics between Li metal anodes and electrolytes.Mg atoms enter the lattice of Li atoms,forming solid solution due to the low amount(5 wt%)of Mg.Mg atoms mainly concentrate near the surface of Mg-alloyed Li metal anodes.The reactivity of Mg-alloyed Li metal is mitigated kinetically,which results from the electron transfer from Li to Mg atoms due to the electronegativity difference.Based on quantitative experimental analysis,the consumption rate of active Li and electrolytes is decreased by using Mgalloyed Li metal anodes,which increases the cycle life of Li metal batteries under demanding conditions.Further,a pouch cell(1.25 Ah)with Mg-alloyed Li metal anodes delivers an energy density of 340 Wh kg^(-1)and a cycle life of 100 cycles.This work inspires the strategy of modifying Li metal anodes to kinetically mitigate the side reactions with electrolytes. 展开更多
关键词 Lithium metal anodes ALLOYING Anode/electrolyte interface Reaction kinetics Pouch cell
下载PDF
Particle aggregation and breakage kinetics in cemented paste backfill
16
作者 Liuhua Yang Hengwei Jia +4 位作者 Aixiang Wu Huazhe Jiao Xinming Chen Yunpeng Kou Mengmeng Dong 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第9期1965-1974,共10页
The macroscopic flow behavior and rheological properties of cemented paste backfill(CPB)are highly impacted by the inherent structure of the paste matrix.In this study,the effects of shear-induced forces and proportio... The macroscopic flow behavior and rheological properties of cemented paste backfill(CPB)are highly impacted by the inherent structure of the paste matrix.In this study,the effects of shear-induced forces and proportioning parameters on the microstructure of fresh CPB were studied.The size evolution and distribution of floc/agglomerate/particles of paste were monitored by focused beam reflection measuring(FBRM)technique,and the influencing factors of aggregation and breakage kinetics of CPB were discussed.The results indicate that influenced by both internal and external factors,the paste kinetics evolution covers the dynamic phase and the stable phase.Increasing the mass content or the cement-tailings ratio can accelerate aggregation kinetics,which is advantageous for the rise of average floc size.Besides,the admixture and high shear can improve breaking kinetics,which is beneficial to reduce the average floc size.The chord length resembles a normal distribution somewhat,with a peak value of approximate 20μm.The particle disaggregation con-stant(k_(2))is positively correlated with the agitation rate,and k_(2) is five orders of magnitude greater than the particle aggregation constant(k1).The kinetics model depicts the evolution law of particles over time quantitatively and provides a theoretical foundation for the micromechanics of complicated rheological behavior of paste. 展开更多
关键词 cemented paste backfill particle kinetics ADMIXTURE rheology
下载PDF
Synthesis of NaY zeolite from a submolten depolymerized perlite:Alkalinity effect and crystallization kinetics
17
作者 Yanli Qu Peng Dong +4 位作者 Li Yang Yuanyuan Yue Haoliang Wang Jingcai Cheng Chao Yang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第6期130-138,共9页
NaY zeolites are synthesized using submolten salt depolymerized natural perlite mineral as the main silica and alumina sources in a 0.94 L stirred crystallizer.Effects of alkalinity ranging from 0.38 to 0.55(n(Na_(2)O... NaY zeolites are synthesized using submolten salt depolymerized natural perlite mineral as the main silica and alumina sources in a 0.94 L stirred crystallizer.Effects of alkalinity ranging from 0.38 to 0.55(n(Na_(2)O)/n(SiO_(2)))on the relative crystallinity,textural properties and crystallization kinetics were investigated.The results show that alkalinity exerts a nonmonotonic influence on the relative crystallinity and textural properties,which exhibit a maximum at the alkalinity of 0.43.The nucleation kinetics are studied by fitting the experimental data of relative crystallinity with the Gualtieri model.It is shown that the nucleation rate constant increases with increasing alkalinity,while the duration period of nucleation decreases with increasing alkalinity.For n(Na_(2)O)/n(SiO_(2))ratios ranging from 0.38 to 0.55,the as-synthesized NaY zeolites exhibit narrower crystal size distributions with the increase in alkalinity.The growth rates determined from the variations of average crystal size with time are 51.09,157.50,46.17 and 24.75 nm·h^(-1),respectively.It is found that the larger average crystal sizes at the alkalinity of 0.38 and 0.43 are attributed to the dominant role of crystal growth over nucleation.Furthermore,the combined action of prominent crystal growth and the longer duration periods of nucleation at the alkalinity of 0.38 and 0.43 results in broader crystal size distributions.The findings demonstrate that control of the properties of NaY zeolite and the crystallization kinetics can be achieved by conducting the crystallization process in an appropriate range of alkalinity of the reaction mixture. 展开更多
关键词 NaY zeolite Submolten salt depolymerized perlite ALKALINITY Crystallization kinetics
下载PDF
Tungsten oxide/nitrogen-doped carbon nanotubes composite catalysts for enhanced redox kinetics in lithium-sulfur batteries
18
作者 Deqing He Zihao Xie +2 位作者 Qian Yang Wei Wang Chao Su 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第3期58-67,共10页
The sluggish redox kinetics of polysulfides in lithium-sulfur(Li-S)batteries are a significant obstacle to their widespread adoption as energy storage devices.However,recent studies have shown that tungsten oxide(WO_(... The sluggish redox kinetics of polysulfides in lithium-sulfur(Li-S)batteries are a significant obstacle to their widespread adoption as energy storage devices.However,recent studies have shown that tungsten oxide(WO_(3))can facilitate the conversion kinetics of polysulfides in Li-S batteries.Herein,we fabricated host materials for sulfur using nitrogen-doped carbon nanotubes(N-CNTs)and WO_(3).We used low-cost components and simple procedures to overcome the poor electrical conductivity that is a disadvantage of metal oxides.The composites of WO_(3) and N-CNTs(WO_(3)/N-CNTs)create a stable framework structure,fast ion diffusion channels,and a 3D electron transport network during electrochemical reaction processes.As a result,the WO_(3)/N-CNT-Li2S6 cathode demonstrates high initial capacity(1162 mA·h·g^(-1) at 0.5℃),excellent rate performance(618 mA·h·g^(-1) at 5.5℃),and a low capacity decay rate(0.093%up to 600 cycles at 2℃).This work presents a novel approach for preparing tungsten oxide/carbon composite catalysts that facilitate the redox kinetics of polysulfide conversion. 展开更多
关键词 Li-S batteries Composites Ion diffusion channels 3D electron transport network Redox kinetics
下载PDF
Atomic Ni directional-substitution on ZnIn_(2)S_(4) nanosheet to achieve the equilibrium of elevated redox capacity and efficient carrier-kinetics performance in photocatalysis
19
作者 Haibin Huang Guiyang Yu +5 位作者 Xingze Zhao Boce Cui Jinshi Yu Chenyang Zhao Heyuan Liu Xiyou Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期272-281,I0007,共11页
It is a challenge to coordinate carrier-kinetics performance and the redox capacity of photogenerated charges synchronously at the atomic level for boosting photocatalytic activity.Herein,the atomic Ni was introduced ... It is a challenge to coordinate carrier-kinetics performance and the redox capacity of photogenerated charges synchronously at the atomic level for boosting photocatalytic activity.Herein,the atomic Ni was introduced into the lattice of hexagonal ZnIn_(2)S_(4) nanosheets(Ni/ZnIn_(2)S_(4))via directionalsubstituting Zn atom with the facile hydrothermal method.The electronic structure calculations indicate that the introduction of Ni atom effectively extracts more electrons and acts as active site for subsequent reduction reaction.Besides the optimized light absorption range,the elevation of Efand ECBendows Ni/ZnIn_(2)S_(4) photocatalyst with the increased electron concentration and the enhanced reduction ability for surface reaction.Moreover,ultrafast transient absorption spectroscopy,as well as a series of electrochemical tests,demonstrates that Ni/ZnIn_(2)S_(4) possesses 2.15 times longer lifetime of the excited charge carriers and an order of magnitude increase for carrier mobility and separation efficiency compared with pristine ZnIn_(2)S_(4).These efficient kinetics performances of charge carriers and enhanced redox capacity synergistically boost photocatalytic activity,in which a 3-times higher conversion efficiency of nitrobenzene reduction was achieved upon Ni/ZnIn_(2)S_(4).Our study not only provides in-depth insights into the effect of atomic directional-substitution on the kinetic behavior of photogenerated charges,but also opens an avenue to the synchronous optimization of redox capacity and carrier-kinetics performance for efficient solar energy conversion. 展开更多
关键词 ZnIn_(2)S_(4) SUBSTITUTION Carrier kinetics Redox capacity PHOTOCATALYSIS
下载PDF
Plasma-assisted aerogel interface engineering enables uniform Zn^(2+)flux and fast desolvation kinetics toward zinc metal batteries
20
作者 Zijian Xu Zhenhai Shi +7 位作者 Zhan Chang Fan Feng Zhuanyi Liu Dongkun Chu Jianguo Ren Zi-Feng Ma Suli Chen Tianxi Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期29-38,I0002,共11页
The poor reversibility of Zn anodes induced by dendrite growth,surface passivation,and corrosion,severely hinders the practical applicability of Zn metal batteries.To address these issues,a plasmaassisted aerogel(PAG)... The poor reversibility of Zn anodes induced by dendrite growth,surface passivation,and corrosion,severely hinders the practical applicability of Zn metal batteries.To address these issues,a plasmaassisted aerogel(PAG)interface engineering was proposed as efficient ion transport modulator that can simultaneously regulate uniform Zn^(2+)flux and desolvation behavior during battery operation.The PAG with ordered mesopores acted as an ion sieve to homogenize Zn deposition and accelerate Zn^(2+)flux,which is favorable for corrosion resistance and dendrite suppression.Importantly,the plasma-assisted aerogel with abundant hydrophilic groups can facilitate the desolvation kinetics of Zn^(2+)due to the multiple hydrogen-bonding interaction with the activated water molecules,thus accelerating the Zn^(2+)migration kinetics.Consequently,the Zn/Zn cell assembled with PAG-modified separator demonstrates stable plating and stripping behavior(over 1400 h at 1 mA cm^(-2))and high Coulombic efficiency(99.8%at1 mA cm^(-2)after 1100 cycles),and the Zn‖MnO_(2)full cell shows excellent long-term cycling stability and maintains a high capacity of 154.9 mA h g^(-1)after 1000 cycles at 1 A g^(-1).This study provides a feasible approach for the large-scale fabrication of aerogel functionalized separators to realize ultra-stable Zn metal batteries. 展开更多
关键词 Zn metal batteries Aerogel interface Plasma Zn^(2+)migration kinetics Dendrite growth
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部