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Role of iron ore in enhancing gasification of iron coke:Structural evolution,influence mechanism and kinetic analysis
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作者 Jie Wang Wei Wang +4 位作者 Xuheng Chen Junfang Bao Qiuyue Hao Heng Zheng Runsheng Xu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第1期58-69,共12页
The utilization of iron coke provides a green pathway for low-carbon ironmaking.To uncover the influence mechanism of iron ore on the behavior and kinetics of iron coke gasification,the effect of iron ore on the micro... The utilization of iron coke provides a green pathway for low-carbon ironmaking.To uncover the influence mechanism of iron ore on the behavior and kinetics of iron coke gasification,the effect of iron ore on the microstructure of iron coke was investigated.Furthermore,a comparative study of the gasification reactions between iron coke and coke was conducted through non-isothermal thermogravimetric method.The findings indicate that compared to coke,iron coke exhibits an augmentation in micropores and specific surface area,and the micropores further extend and interconnect.This provides more adsorption sites for CO_(2) molecules during the gasification process,resulting in a reduction in the initial gasification temperature of iron coke.Accelerating the heating rate in non-isothermal gasification can enhance the reactivity of iron coke.The metallic iron reduced from iron ore is embedded in the carbon matrix,reducing the orderliness of the carbon structure,which is primarily responsible for the heightened reactivity of the carbon atoms.The kinetic study indicates that the random pore model can effectively represent the gasification process of iron coke due to its rich pore structure.Moreover,as the proportion of iron ore increases,the activation energy for the carbon gasification gradually decreases,from 246.2 kJ/mol for coke to 192.5 kJ/mol for iron coke 15wt%. 展开更多
关键词 low-carbon ironmaking iron coke GASIFICATION structural evolution kinetic model
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New insights into the pre-lithiation kinetics of single-crystalline Ni-rich cathodes for long-life Li-ion batteries 被引量:1
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作者 Qiang Han Lele Cai +3 位作者 Zhaofeng Yang Yanjie Hu Hao Jiang Chunzhong Li 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第3期556-564,共9页
Developing single-crystalline Ni-rich cathodes is an effective strategy to improve the safety and cycle life of Li-ion batteries(LIBs).However,the easy-to-loss of Li and O in high-temperature lithiation results in uns... Developing single-crystalline Ni-rich cathodes is an effective strategy to improve the safety and cycle life of Li-ion batteries(LIBs).However,the easy-to-loss of Li and O in high-temperature lithiation results in unsatisfactory ordered layered structure and stoichiometry.Herein,we demonstrate the synthesis of highly-ordered and fully-stoichiometric single-crystalline LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(SC-NCM83)cathodes by the regulation of pre-lithiation kinetics.The well-balanced pre-lithiation kinetics have been proved to greatly improve the proportion of layered phase in the intermediate by inhibiting the formation of metastable spinel phase,which promoted the rapid transformation of the intermediate into highly-ordered layered SC-NCM83 in the subsequent lithiation process.After coating a layer of Li_(2)O–B_(2)O_(3),the resultant cathodes deliver superior cycling stability with 90.9%capacity retention at 1C after 300 cycles in pouch-type full batteries.The enhancement mechanism has also been clarified.These findings exhibit fundamental insights into the pre-lithiation kinetics process for guiding the synthesis of high-quality singlecrystalline Ni-rich cathodes. 展开更多
关键词 Single-crystalline cathode Ni-rich oxides Pre-lithiation li-ion batteries Surface modification
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A high Li-ion diffusion kinetics in multidimensional and compact-structured electrodes via vacuum filtration casting 被引量:1
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作者 Jieqiong Li Ting Ouyang +3 位作者 Lu Liu Shu Jiang Yongchao Huang M.-Sadeeq Balogun 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期368-376,I0010,共10页
Manufacturing process,diffusion co-efficient and areal capacity are the three main criteria for regulating thick electrodes for lithium-ion batteries(LIBs).However,simultaneously regulating these criteria for LIBs is ... Manufacturing process,diffusion co-efficient and areal capacity are the three main criteria for regulating thick electrodes for lithium-ion batteries(LIBs).However,simultaneously regulating these criteria for LIBs is desirable but remains a significant challenge.In this work,niobium pentoxide(Nb_(2)O_(5))anode and lithium iron phosphate(LiFePO_(4))cathode materials were chosen as the model materials and demonstrate that these three parameters can be simultaneously modulated by incorporation of micro-carbon fibers(MCF)and carbon nanotubes(CNT)with both Nb_(2)O_(5) and LFP via vacuum filtration approach.Both as-prepared MNC-20 anode and MLC-20 cathode achieves high reversible areal capacity of≈5.4 m A h cm^(-2)@0.1 C and outstanding Li-ion diffusion coefficients of≈10~(-8)cm~2 s~(-1)in the half-cell configuration.The assembled MNC-20‖MLC-20 full cell LIB delivers maximum energy and power densities of244.04 W h kg^(-1)and 108.86 W kg^(-1),respectively.The excellent electrochemical properties of the asprepared thick electrodes can be attributed to the highly conductive,mechanical compactness and multidimensional mutual effects of the MCF,CNT and active materials that facilitates rapid Li-ion diffusion kinetics.Furthermore,electrochemical impedance spectroscopy(EIS),symmetric cells analysis,and insitu Raman techniques clearly validates the enhanced Li-ion diffusion kinetics in the present architecture. 展开更多
关键词 Thick electrodes Carbon nanotubes li-ion diffusion co-efficient Vacuum filtration technique High areal capacity Lithium-ion batteries
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All‑Covalent Organic Framework Nanofilms Assembled Lithium‑Ion Capacitor to Solve the Imbalanced Charge Storage Kinetics 被引量:2
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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
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“Buckets effect”in the kinetics of electrocatalytic reactions 被引量:2
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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
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Dual-single-atoms of Pt-Co boost sulfur redox kinetics for ultrafast Li-S batteries 被引量:2
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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
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Boosted Lithium-Ion Transport Kinetics in n-Type Siloxene Anodes Enabled by Selective Nucleophilic Substitution of Phosphorus
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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
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Plasma-assisted aerogel interface engineering enables uniform Zn^(2+)flux and fast desolvation kinetics toward zinc metal batteries 被引量:1
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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
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Recent progress in thermodynamic and kinetics modification of magnesium hydride hydrogen storage materials 被引量:1
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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
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Alleviating the sluggish kinetics of all-solid-state batteries via cathode single-crystallization and multi-functional interface modification
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作者 Wen-Zhe Liu Xin-Hai Meng +4 位作者 Zi-Yi Zhou Qiang Zheng Ji-Lei Shi Yue Gong Yu-Guo Guo 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第11期123-133,共11页
The application of Li-rich Mn-based cathodes, the most promising candidates for high-energy-density Liion batteries, in all-solid-state batteries can further enhance the safety and stability of battery systems.However... The application of Li-rich Mn-based cathodes, the most promising candidates for high-energy-density Liion batteries, in all-solid-state batteries can further enhance the safety and stability of battery systems.However, the utilization of high-capacity Li-rich cathodes has been limited by sluggish kinetics and severe interfacial issues in all-solid-state batteries. Here, a multi-functional interface modification strategy involving dispersed submicron single-crystal structure and multi-functional surface modification layer obtained through in-situ interfacial chemical reactions was designed to improve the electrochemical performance of Li-rich Mn-based cathodes in all-solid-state batteries. The design of submicron single-crystal structure promotes the interface contact between the cathode particles and the solid-state electrolyte,and thus constructs a more complete ion and electron conductive network in the composite cathode.Furthermore, the Li-gradient layer and the lithium molybdate coating layer constructed on the surface of single-crystal Li-rich particles accelerate the transport of Li ions at the interface, suppress the side reactions between cathodes and electrolyte, and inhibit the oxygen release on the cathode surface. The optimized Li-rich cathode materials exhibit excellent electrochemical performance in halide all-solid-state batteries. This study emphasizes the vital importance of reaction kinetics and interfacial stability of Lirich cathodes in all-solid-state batteries and provides a facile modification strategy to enhance the electrochemical performance of all-solid-state batteries based on Li-rich cathodes. 展开更多
关键词 All-solid-state li-ion batteries Li-rich Mn-based cathode materials kineticS Interface Anion redox
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Diagnosis of the Kinetic Energy of the“21·7”Extreme Torrential Rainfall Event in Henan Province,China
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作者 Xiuping YAO Ruoying LI +1 位作者 Xiaohong BAO Qiaohua LIU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第1期73-83,共11页
An extreme torrential rain(ETR)event occurred in Henan Province,China,during 18-21 July 2021.Based on hourly rain-gauge observations and ERA5 reanalysis data,the ETR was studied from the perspective of kinetic energy(... An extreme torrential rain(ETR)event occurred in Henan Province,China,during 18-21 July 2021.Based on hourly rain-gauge observations and ERA5 reanalysis data,the ETR was studied from the perspective of kinetic energy(K),which can be divided into rotational wind(V_(R))kinetic energy(K_(R)),divergent wind kinetic energy(K_(D)),and the kinetic energy of the interaction between the divergent and rotational winds(K_(RD)).According to the hourly precipitation intensity variability,the ETR process was divided into an initial stage,a rapid increase stage,and maintenance stage.Results showed that the intensification and maintenance of ETR were closely related to the upper-level K,and most closely related to the upperlevel K_(R),with a correlation coefficient of up to 0.9.In particular,the peak value of hourly rainfall intensity lagged behind the K_(R) by 8 h.Furthermore,diagnosis showed that K transformation from unresolvable to resolvable scales made the ETR increase slowly.The meridional rotational wind(u_(R))and meridional gradient of the geopotential(φ)jointly determined the conversion of available potential energy(APE)to K_(R) through the barotropic process,which dominated the rapid enhancement of K_(R) and then caused the rapid increase in ETR.The transportation of K by rotational wind consumed K_(R),and basically offset the K_(R) produced by the barotropic process,which basically kept K_(R) stable at a high value,thus maintaining the ETR. 展开更多
关键词 extreme torrential rain rotational kinetic energy kinetic energy generation and transport barotropic process
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Li-Rich Organosulfur Cathode with Boosted Kinetics for High-Energy Lithium-Sulfur Batteries
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作者 Ting Ma Jiaojiao Deng +8 位作者 Yuxiao Lin Qinghua Liang Liang Hu Xiaohu Wang Jun Liu Xinsheng Zhao Yinwei Li Ding Nan Xiaoliang Yu 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第4期118-125,共8页
Organosulfur materials containing sulfur-sulfur bonds are an emerging class of high-capacity cathodes for lithium storage.However,it remains a great challenge to achieve rapid conversion reaction kinetics at practical... Organosulfur materials containing sulfur-sulfur bonds are an emerging class of high-capacity cathodes for lithium storage.However,it remains a great challenge to achieve rapid conversion reaction kinetics at practical testing conditions of high cathode mass loading and low electrolyte utilization.In this study,a Li-rich pyrolyzed polyacrylonitrile/selenium disulfide(pPAN/Se_(2)S_(3))composite cathode is synthesized by deep lithiation to address the above challenges.The Li-rich molecular structure significantly boosts the lithium storage kinetics by accelerating lithium diffusivity and improving electronic conductivity.Even under practical test conditions requiring a lean electrolyte(Electrolyte/sulfur ratio of 4.1μL mg^(-1))and high loading(7 mg cm^(-2)of pPAN/Se_(2)S_(3)),DL-pPAN/Se_(2)S_(3)exhibits a specific capacity of 558 mAh g^(-1),maintaining 484 mAh g^(-1)at the 100th cycle with an average Coulombic efficiency of near 100%.Moreover,it provides(electro)chemically stable Li resources to offset Li consumption over charge-discharge cycles.As a result the as-fabricated anode-free cell shows a superior cycling stability with 90%retention of the initial capacity over 45 cycles.This study provides a novel approach for fabricating high-energy and stable Li-SPAN cells. 展开更多
关键词 LITHIUM kineticS ELECTROLYTE
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Electron kinetic effects in back-stimulated Raman scattering bursts driven by broadband laser pulses
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作者 Q.K.Liu L.Deng +6 位作者 Q.Wang X.Zhang F.Q.Meng Y.P.Wang Y.Q.Gao H.B.Cai S.P.Zhu 《Matter and Radiation at Extremes》 SCIE EI CSCD 2024年第4期54-67,共14页
We examine electron kinetic effects in broadband-laser-driven back-stimulated Raman scattering(BSRS)bursts using particle-in-cell simulations.These bursts occur during the nonlinear stage,causing reflectivity spikes a... We examine electron kinetic effects in broadband-laser-driven back-stimulated Raman scattering(BSRS)bursts using particle-in-cell simulations.These bursts occur during the nonlinear stage,causing reflectivity spikes and generating large numbers of hot electrons.Long-duration simulations are performed to observe burst events,and a simplified model is developed to eliminate the interference of the broadband laser’s random intensity fluctuations.Using the simplified model,we isolate and characterize the spectrum of electron plasma waves.The spectrum changes from a sideband structure to a turbulence-like structure during the burst.A significant asymmetry in the spectrum is observed.This asymmetry is amplified and transferred to electron phase space by high-intensity broadband laser pulses,leading to violent vortex-merging and generation of hot electrons.The proportion of hot electrons increases from 6.76%to 14.7%during a single violent burst event.We demonstrate that kinetic effects profoundly influence the BSRS evolution driven by broadband lasers. 展开更多
关键词 SCATTERING kinetic simplified
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Confining ultrahigh oxygen vacancy SnO_(2) nanocrystals into nitrogen-doped carbon for enhanced Li-ion storage kinetics and reversibility 被引量:2
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作者 Ying Liu Chen Hu +3 位作者 Ling Chen Yanjie Hu Hao Jiang Chunzhong Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第6期450-455,I0013,共7页
Oxygen vacancies (V_(o)) engineering has been deemed to an effective tactic for enhancing Li-ion storage kinetics and reversibility of SnO_(2)-based anode materials.Herein,we demonstrated the confinement of ultrahigh ... Oxygen vacancies (V_(o)) engineering has been deemed to an effective tactic for enhancing Li-ion storage kinetics and reversibility of SnO_(2)-based anode materials.Herein,we demonstrated the confinement of ultrahigh V_(o)SnO_(2) nanocrystals into N-doped carbon frameworks to boost their high-rate and cycle life.Density functional theory (DFT) calculations reveal that abundant V_(o) in SnO_(2) facilitates the adsorption to Li-ion with remarkably increased carrier concentration.The 6.0 nm-sized SnO_(2) particles and the embedded design effectively stabilize the structural integrity during de-/lithiation.Meantime,the as-formed large hetero-interface also expedites the electron transfer.These merits guarantee its high-rate performance and superior cycling stability.Consequently,this sample exhibits a high capacity of 1368.9m Ah g^(-1)at 0.1 A g^(-1),and can still maintain 488.5 mAh g^(-1)at 10 A g^(-1)and a long life over 400 cycles at 5 A g^(-1)with 96.6%capacity retention,which is among the best report for Sn-contained anode materials.This work sheds light on ultrahigh Vo and structural design in conversion-type oxides for highperformance lithium-ion batteries (LIBs). 展开更多
关键词 li-ion batteries SnO_(2) Oxygen vacancy Confined synthesis Rate capability
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Experiments and kinetic modeling of the sorbitol dehydration to isosorbide catalyzed by sulfuric acid under conditions of non-constant volume
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作者 Dechang Cheng Zhihong Ma +4 位作者 Ziyang Liu Xiaohui Liu Tao Liu Weizhen Sun Ling Zhao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第9期281-289,共9页
Isosorbide is a novel bio-based material derived as a secondary dehydration product of sorbitol.This work focuses on the kinetics of sulfuric acid-catalyzed dehydration of sorbitol under conditions of nonconstant volu... Isosorbide is a novel bio-based material derived as a secondary dehydration product of sorbitol.This work focuses on the kinetics of sulfuric acid-catalyzed dehydration of sorbitol under conditions of nonconstant volume.Herein,the effects of stirring rate,catalyst dosage,reaction temperature,and reaction time on the dehydration reaction of sorbitol were investigated.The yield of isosorbide up to 77.13%was obtained after 1.5 h of reaction time under conditions of 2 kPa,1.0%(mass)catalyst dosage,and 413.15 K.Based on the sorbitol dehydration reaction mechanism and a simplified reaction network,a kinetic model was developed in this work.A good agreement was accomplished between kinetic modeling and experiments between 393.15 and 423.15 K.The fitting results indicate that side reactions with higher activation energies are more affected by reaction temperatures,and the main side reaction that influences the selectivity of isosorbide is the oligomerization reaction among the primary dehydration products of sorbitol.The model fitting of the catalyst amounts effect shows that the effective concentration of sulfuric acid would be reduced with the increase of dosage due to the molecular agglomeration effect.Hopefully,the kinetic experiments and modeling results obtained in this work will be helpful to the design and optimization of the industrial sorbitol dehydration process. 展开更多
关键词 ISOSORBIDE Sorbitol dehydration Non-constant volume kinetic modeling
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Growth kinetics of titanium carbide coating by molten salt synthesis process on graphite sheet surface
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作者 Xiaoyu Shi Chongxiao Guo +4 位作者 Jiamiao Ni Songsong Yao Liqiang Wang Yue Liu Tongxiang Fan 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第8期1858-1864,共7页
The synthesis of carbide coatings on graphite substrates using molten salt synthesis(MSS),has garnered significant interest due to its cost-effective nature.This study investigates the reaction process and growth kine... The synthesis of carbide coatings on graphite substrates using molten salt synthesis(MSS),has garnered significant interest due to its cost-effective nature.This study investigates the reaction process and growth kinetics involved in MSS,shedding light on key aspects of the process.The involvement of Ti powder through liquid-phase mass transfer is revealed,where the diffusion distance and quantity of Ti powder play a crucial role in determining the reaction rate by influencing the C content gradient on both sides of the carbide.Furthermore,the growth kinetics of the carbide coating are predominantly governed by the diffusion behavior of C within the carbide layer,rather than the chemical reaction rate.To analyze the kinetics,the thickness of the carbide layer is measured with respect to heat treatment time and temperature,unveiling a parabolic relationship within the temperature range of 700-1300℃.The estimated activation energy for the reaction is determined to be 179283 J·mol^(-1).These findings offer valuable insights into the synthesis of carbide coatings via MSS,facilitating their optimization and enhancing our understanding of their growth mechanisms and properties for various applications. 展开更多
关键词 titanium carbide GRAPHITE molten salt kinetic analysis
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Continuous synthesis of N,N-dicyanoethylaniline in microreactors:Reaction kinetics and process intensification
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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
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Kinetics insights into size effects of carbon nanotubes'growth and their supported platinum catalysts for 4,6-dinitroresorcinol hydrogenation
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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
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Particle aggregation and breakage kinetics in cemented paste backfill
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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
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Canine Myofascial Kinetic Lines: A Descriptive Dissection Study Including Related Function and Locomotion and Comparison of the Human and Equine Myofascial Kinetic Lines
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作者 Vibeke S. Elbrønd 《Open Journal of Veterinary Medicine》 CAS 2024年第9期229-256,共28页
Aim: This dissection study was conducted to verify if the Myofascial kinetic lines, outlined in detail in humans and recently documented in horses, were present in dogs. These dynamic lines present rows of interconnec... Aim: This dissection study was conducted to verify if the Myofascial kinetic lines, outlined in detail in humans and recently documented in horses, were present in dogs. These dynamic lines present rows of interconnected muscles, myofascia and other fascia structures, which influence the biomechanics of the spine and limbs. Methods: Forty-two dogs of different breeds and genders were dissected, imaged, and videoed. Results: Similar kinetic lines were verified in the dog, as described in humans and horses, and additionally, three new branches of the lines were discovered. The kinetic lines described were three superficial lines: Dorsal, Ventral, and Lateral, which all started in the hindlimb and ended in the temporal and occipital regions. These lines act respectively in spinal extension, flexion, and lateral flexion. Three profound lines, which started in the tail and ended in the head. The Deep Dorsal Line followed the transversospinal myofascia. The Deep Ventral Line showed an additional start deep in the medial hind limb, continued in the hypaxial myofascia, and enveloped all the viscera. Also, the Deep Lateral Line started in the hindlimb but parted along the trunk in the deep lateral myofascial structures. Two helical lines crossed the midline two or three times and served to rotate the spine. The Functional Line established a sling from the axilla to the contralateral stifle and presented a new ipsilateral branch. The Spiral Line connected the head and the ipsilateral tarsus and additionally presented a new straight branch. The four front limb lines describe their motion: the Front Limb Protraction and Retraction, Adduction, and Abduction Lines. Conclusion: The canine lines mirrored the equine and human lines with exceptions due to differences in anatomy, foot posture, lumbosacral flexibility, and their biomechanical constitution as predator versus prey animals. Additionally, three new canine branches were verified and described. 展开更多
关键词 Myofascial kinetic Lines Canis Familiaris Superficial Lines Deep Lines Locomotive Connections Viscero-Somatic Connections
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