In order to confirm the optimal Li content of Li-rich Mn-based cathode materials(a fixed mole ratio of Mn to Ni to Co is0.6:0.2:0.2),Li1+x(Mn0.6Ni0.2Co0.2)1-xO2(x=0,0.1,0.2,0.3)composites were obtained,which had a typ...In order to confirm the optimal Li content of Li-rich Mn-based cathode materials(a fixed mole ratio of Mn to Ni to Co is0.6:0.2:0.2),Li1+x(Mn0.6Ni0.2Co0.2)1-xO2(x=0,0.1,0.2,0.3)composites were obtained,which had a typical layered structure with R3m and C2/m space group observed from X-ray powder diffraction(XRD).Electron microscopy micrograph(SEM)reveals that the particle sizes in the range of0.4-1.1μm increase with an increase of x value.Li1.2(Mn0.6Ni0.2Co0.2)0.8O2sample delivers a larger initial discharge capacity of275.7mA·h/g at the current density of20mA/g in the potential range of2.0-4.8V,while Li1.1(Mn0.6Ni0.2Co0.2)0.9O2shows a better cycle performance with a capacity retention of93.8%at0.2C after50cycles,showing better reaction kinetics of lithium ion insertion and extraction.展开更多
P2-type Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2) was synthesized by a facile sol−gel method,and the effect of calcination temperature on the structure,morphology and electrochemical performance of samples was investigated.The re...P2-type Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2) was synthesized by a facile sol−gel method,and the effect of calcination temperature on the structure,morphology and electrochemical performance of samples was investigated.The results show that the sample obtained at 900℃ is pure P2-type Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2) phase with good crystallization,which consists of hexagon plate-shaped particles with the size and thickness of 2−4μm and 200−400 nm,respectively.The sample exhibits an initial specific discharge capacity of 243 mA·h/g at a current density of 26 mA/g with good cycling stability.The high specific capacity indicates that P2-type Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2) is a promising cathode material for sodiumion batteries.展开更多
A simple and effective method has been developed to reflect the growth of bacteria CH-1via the potential of the solution.The results indicate that during the bacterial cultivation,the biomass increases and the potenti...A simple and effective method has been developed to reflect the growth of bacteria CH-1via the potential of the solution.The results indicate that during the bacterial cultivation,the biomass increases and the potential of the solution decreases over time.The relationship between biomass and potential of the solution could be expressed by the equation with constants of a and b whichare all related to species,batch,number,and growth environment of bacterial.When the initial pH value is10and the initial biomassis6.55×107cell/mL,the correlated equation of the biomass and the potential of the solution could be divided into two segments.Thegrowth of bacteria CH-1is different under various experimental conditions,but the biomass is directly related to the potential of thesolution regardless of the conditions of different initial pH values and bacteria number.展开更多
Development of the high activity,promoter‐free catalysts for carbonyl sulfide(COS)hydrolysis is important for the efficient utilization of various feedstocks.In this study,the Cu‐based metal‐organic framework HKUST...Development of the high activity,promoter‐free catalysts for carbonyl sulfide(COS)hydrolysis is important for the efficient utilization of various feedstocks.In this study,the Cu‐based metal‐organic framework HKUST‐1is synthesized by a simple and mild anodic‐dissolution electrochemical method.The physical and chemical properties of the samples are characterized by several techniques,including scanning electron microscopy,X‐ray diffraction,Brunauer‐Emmett‐Teller analysis and X‐ray photoelectron spectroscopy.The results reveal that the synthesis voltage plays a crucial role in controlling the morphology of the resulting HKUST‐1.The obtained samples function as novel catalysts for the hydrolysis of COS.A high efficiency,approaching100%,can be achieved for the conversion of COS at150oC over the optimal HKUST‐1synthesized at25V.This is significantly higher than that of the sample prepared by the traditional hydrothermal method.Additionally,the effects of the water temperature and the flow velocity on the hydrolysis of COS are also investigated in detail.Finally,a possible reaction pathway of COS hydrolysis over HKUST‐1is also proposed.This work represents the first example of MOFs applied to the catalytic hydrolysis of COS.The results presented in this study can be anticipated to give a feasible impetus to design novel catalysts for removing the sulfur‐containing compounds.展开更多
基金Project(21473258) supported by the National Natural Science Foundation of ChinaProject(13JJ1004) supported by Distinguished Young Scientists of Hunan Province,ChinaProject(NCET-11-0513) supported by Program for the New Century Excellent Talents in University,China
文摘In order to confirm the optimal Li content of Li-rich Mn-based cathode materials(a fixed mole ratio of Mn to Ni to Co is0.6:0.2:0.2),Li1+x(Mn0.6Ni0.2Co0.2)1-xO2(x=0,0.1,0.2,0.3)composites were obtained,which had a typical layered structure with R3m and C2/m space group observed from X-ray powder diffraction(XRD).Electron microscopy micrograph(SEM)reveals that the particle sizes in the range of0.4-1.1μm increase with an increase of x value.Li1.2(Mn0.6Ni0.2Co0.2)0.8O2sample delivers a larger initial discharge capacity of275.7mA·h/g at the current density of20mA/g in the potential range of2.0-4.8V,while Li1.1(Mn0.6Ni0.2Co0.2)0.9O2shows a better cycle performance with a capacity retention of93.8%at0.2C after50cycles,showing better reaction kinetics of lithium ion insertion and extraction.
基金the financial supports from the Natural Science Foundation of Hunan Province,China(No.2020JJ5102)the Scientific Research Fund of Hunan Provincial Education Department,China(No.19A111).
文摘P2-type Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2) was synthesized by a facile sol−gel method,and the effect of calcination temperature on the structure,morphology and electrochemical performance of samples was investigated.The results show that the sample obtained at 900℃ is pure P2-type Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2) phase with good crystallization,which consists of hexagon plate-shaped particles with the size and thickness of 2−4μm and 200−400 nm,respectively.The sample exhibits an initial specific discharge capacity of 243 mA·h/g at a current density of 26 mA/g with good cycling stability.The high specific capacity indicates that P2-type Na_(2/3)Fe_(1/2)Mn_(1/2)O_(2) is a promising cathode material for sodiumion batteries.
基金Projects(51304251,51504299)supported by the National Natural Science Foundation of ChinaProject(201509050)supported by Special Program on Environmental Protection for Public Welfare,China
文摘A simple and effective method has been developed to reflect the growth of bacteria CH-1via the potential of the solution.The results indicate that during the bacterial cultivation,the biomass increases and the potential of the solution decreases over time.The relationship between biomass and potential of the solution could be expressed by the equation with constants of a and b whichare all related to species,batch,number,and growth environment of bacterial.When the initial pH value is10and the initial biomassis6.55×107cell/mL,the correlated equation of the biomass and the potential of the solution could be divided into two segments.Thegrowth of bacteria CH-1is different under various experimental conditions,but the biomass is directly related to the potential of thesolution regardless of the conditions of different initial pH values and bacteria number.
基金supported by the National Natural Science Foundation of China (21603034,21576051)the National High Technology Research and Development Program of China (863 Program,2015AA03A402)~~
文摘Development of the high activity,promoter‐free catalysts for carbonyl sulfide(COS)hydrolysis is important for the efficient utilization of various feedstocks.In this study,the Cu‐based metal‐organic framework HKUST‐1is synthesized by a simple and mild anodic‐dissolution electrochemical method.The physical and chemical properties of the samples are characterized by several techniques,including scanning electron microscopy,X‐ray diffraction,Brunauer‐Emmett‐Teller analysis and X‐ray photoelectron spectroscopy.The results reveal that the synthesis voltage plays a crucial role in controlling the morphology of the resulting HKUST‐1.The obtained samples function as novel catalysts for the hydrolysis of COS.A high efficiency,approaching100%,can be achieved for the conversion of COS at150oC over the optimal HKUST‐1synthesized at25V.This is significantly higher than that of the sample prepared by the traditional hydrothermal method.Additionally,the effects of the water temperature and the flow velocity on the hydrolysis of COS are also investigated in detail.Finally,a possible reaction pathway of COS hydrolysis over HKUST‐1is also proposed.This work represents the first example of MOFs applied to the catalytic hydrolysis of COS.The results presented in this study can be anticipated to give a feasible impetus to design novel catalysts for removing the sulfur‐containing compounds.
