To investigate the performance of landfill composite liner system,a one-dimensional model was developed for solute transport through composite liners containing geomembrane defects.An analytical solution to the model ...To investigate the performance of landfill composite liner system,a one-dimensional model was developed for solute transport through composite liners containing geomembrane defects.An analytical solution to the model was obtained by the method of Laplace transformation.The results obtained by the presented solution agree well with those obtained by the numerical method.Results show that leachate head and construction quality of geomembrane(GM) have significant influences on the performance of the composite liners for heavy metal ions.The breakthrough time of lead decreases from 50 a to 19 a when the leachate head increases from 0.3 m to 10 m.It is also indicated that the contaminant mass flux of volatile organic compounds(VOCs) induced by leakage can not be neglected in case of poor construction quality of the landfill barrier system.It is shown that diffusion coefficient and partition coefficient of GM have great influences on solute transport through composite liners for VOCs.The breakthrough time of heavy metal ions will be greatly overestimated if the effects of diffusion and adsorption of clay and geosynthetic clay liner(GCL) are neglected.The composite liner consisting of a geomembrane and a GCL provides a poor barrier for VOCs.The presented analytical solution is relatively simple to apply and can be used for preliminary design of composite liners,evaluating experimental results,and verifying more complex numerical models.展开更多
In comparison with lithium-ion batteries(LIBs)with liquid electrolytes,all-solid-state lithium batteries(ASSLBs)have been considered as promising systems for future energy storage due to their safety and high energy d...In comparison with lithium-ion batteries(LIBs)with liquid electrolytes,all-solid-state lithium batteries(ASSLBs)have been considered as promising systems for future energy storage due to their safety and high energy density.As the pivotal component used in ASSLBs,composite solid polymer electrolytes(CSPEs),derived from the incorporation of inorganic fillers into solid polymer electrolytes(SPEs),exhibit higher ionic conductivity,better mechanical strength,and superior thermal/electrochemical stability compared to the single-component SPEs,which can significantly promote the electrochemical performance of ASSLBs.Herein,the recent advances of CSPEs applied in ASSLBs are presented.The effects of the category,morphology and concentration of inorganic fillers on the ionic conductivity,mechanical strength,electrochemical window,interfacial stability and possible Li+transfer mechanism of CSPEs will be systematically discussed.Finally,the challenges and perspectives are proposed for the future development of high-performance CSPEs and ASSLBs.展开更多
Semi-transparent perovskite solar cells(ST-PSCs)have broad applications in building integrated photovoltaics.However,the stability of ST-PSCs needs to be improved,especially in n-i-p ST-PSCs since the doped 2,2',7...Semi-transparent perovskite solar cells(ST-PSCs)have broad applications in building integrated photovoltaics.However,the stability of ST-PSCs needs to be improved,especially in n-i-p ST-PSCs since the doped 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenyl-amine)-9,9'-spirobifluorene(Spiro-OMeTAD)is unstable at elevated temperatures and high humidity.In this work,aπ-conjugated polymer poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophene-2-yl)-benzo[1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione)](PBDB-T)is selected to form a polymer composite hole transport layer(HTL)with Spiro-OMeTAD.The sulfur atom of the thiophene unit and the carbonyl group of the polymer interact with the undercoordinated Pb2+at the perovskite surface,which stabilizes the perovskite/HTL interface and passivates the interfacial defects.The incorporation of the polymer also increases the glass transition temperature and the moisture resistance of Spiro-OMeTAD.As a result,we obtain ST-PSCs with a champion efficiency of 13.71%and an average visible light transmittance of 36.04%.Therefore,a high light utilization efficiency of 4.94%can be obtained.Moreover,the encapsulated device can maintain 84%of the initial efficiency after 751 h under continuous one-sun illumination(at 30%relative humidity)at the open circuit and the unencapsulated device can maintain 80%of the initial efficiency after maximum power tracking for more than 1250 h under continuous one-sun illumination.展开更多
All-solid-state lithium batteries(ASSLBs)are recognized as high energy density batteries system without safety issues within the next generation of batteries.The development of solid electrolytes is the crucial step o...All-solid-state lithium batteries(ASSLBs)are recognized as high energy density batteries system without safety issues within the next generation of batteries.The development of solid electrolytes is the crucial step of ASSLBs.The composite electrolyte has stable physical and electrochemical characteristics,and its comprehensive performance surpasses the individual solid electrolyte,bringing unique vitality to the solid electrolyte.However,their intrinsic weakness limits the development of composite electrolytes.In this review,we provide a comprehensive and in-depth understanding of the challenges and opportunities of composite electrolytes,with special focus on mechanisms of ion transport,nanostructure design towards high ionic conductivity,interfacial issues within electrolytes and electrodes.Furthermore,future development is prospected,which can shed light on researchers in this field and accelerate the industrial production of composite electrolytes.展开更多
New-old concrete composite system usually exists in concrete repairing structure.In the present work,series of experiments were carried out to investigate permeability and ion diffusion properties of new-old concrete ...New-old concrete composite system usually exists in concrete repairing structure.In the present work,series of experiments were carried out to investigate permeability and ion diffusion properties of new-old concrete composite by measuring 6-hour coulomb charge and chloride diffusivity.The interrelation among transport properties of new-old composites,new,and old concretes was also discussed.Results indicate that the permeability and chloride diffusivity of new-old concrete composite system closely interrelate to the corresponding new concrete and old concrete.The interfacial transition zone between new concrete and old concrete greatly influences the transport property of new-old concrete system.Compared with the corresponding new concrete and old concrete lower permeability and diffusivity values for the new-old concrete composites can be achieved by choosing suitable new concrete.It is possible to design the tailor-made new-old concrete composite system for repair given the transport property.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.50538080,40839902)the China National Funds for Distinguished Young Scientists (Grant No.50425825)the National Science Foundation for Post-doctoral Scientists of China (Grant No.20090451472)
文摘To investigate the performance of landfill composite liner system,a one-dimensional model was developed for solute transport through composite liners containing geomembrane defects.An analytical solution to the model was obtained by the method of Laplace transformation.The results obtained by the presented solution agree well with those obtained by the numerical method.Results show that leachate head and construction quality of geomembrane(GM) have significant influences on the performance of the composite liners for heavy metal ions.The breakthrough time of lead decreases from 50 a to 19 a when the leachate head increases from 0.3 m to 10 m.It is also indicated that the contaminant mass flux of volatile organic compounds(VOCs) induced by leakage can not be neglected in case of poor construction quality of the landfill barrier system.It is shown that diffusion coefficient and partition coefficient of GM have great influences on solute transport through composite liners for VOCs.The breakthrough time of heavy metal ions will be greatly overestimated if the effects of diffusion and adsorption of clay and geosynthetic clay liner(GCL) are neglected.The composite liner consisting of a geomembrane and a GCL provides a poor barrier for VOCs.The presented analytical solution is relatively simple to apply and can be used for preliminary design of composite liners,evaluating experimental results,and verifying more complex numerical models.
基金supported by the Innovative and Entrepreneurial Talent Plan(Jiangsu Province,China)。
文摘In comparison with lithium-ion batteries(LIBs)with liquid electrolytes,all-solid-state lithium batteries(ASSLBs)have been considered as promising systems for future energy storage due to their safety and high energy density.As the pivotal component used in ASSLBs,composite solid polymer electrolytes(CSPEs),derived from the incorporation of inorganic fillers into solid polymer electrolytes(SPEs),exhibit higher ionic conductivity,better mechanical strength,and superior thermal/electrochemical stability compared to the single-component SPEs,which can significantly promote the electrochemical performance of ASSLBs.Herein,the recent advances of CSPEs applied in ASSLBs are presented.The effects of the category,morphology and concentration of inorganic fillers on the ionic conductivity,mechanical strength,electrochemical window,interfacial stability and possible Li+transfer mechanism of CSPEs will be systematically discussed.Finally,the challenges and perspectives are proposed for the future development of high-performance CSPEs and ASSLBs.
基金supported by the National Natural Science Foundation of China(Nos.22179042 and U21A2078)the Natural Science Foundation of Fujian Province(Nos.2020J06021 and 2020J01064).
文摘Semi-transparent perovskite solar cells(ST-PSCs)have broad applications in building integrated photovoltaics.However,the stability of ST-PSCs needs to be improved,especially in n-i-p ST-PSCs since the doped 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenyl-amine)-9,9'-spirobifluorene(Spiro-OMeTAD)is unstable at elevated temperatures and high humidity.In this work,aπ-conjugated polymer poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophene-2-yl)-benzo[1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione)](PBDB-T)is selected to form a polymer composite hole transport layer(HTL)with Spiro-OMeTAD.The sulfur atom of the thiophene unit and the carbonyl group of the polymer interact with the undercoordinated Pb2+at the perovskite surface,which stabilizes the perovskite/HTL interface and passivates the interfacial defects.The incorporation of the polymer also increases the glass transition temperature and the moisture resistance of Spiro-OMeTAD.As a result,we obtain ST-PSCs with a champion efficiency of 13.71%and an average visible light transmittance of 36.04%.Therefore,a high light utilization efficiency of 4.94%can be obtained.Moreover,the encapsulated device can maintain 84%of the initial efficiency after 751 h under continuous one-sun illumination(at 30%relative humidity)at the open circuit and the unencapsulated device can maintain 80%of the initial efficiency after maximum power tracking for more than 1250 h under continuous one-sun illumination.
基金financially supported by the National Natural Science Foundation of China(52074359,51904342,U19A2019)the Hunan Provincial Science and Technology Plan(2020JJ3048)+2 种基金the Science and Technology Innovation Program of Hunan Province(2020RC4005,2019RS1004)the science and technology plan key project of Hunan Province(2020GK2100)the Innovation Mover Program of Central South University(2020CX007)。
文摘All-solid-state lithium batteries(ASSLBs)are recognized as high energy density batteries system without safety issues within the next generation of batteries.The development of solid electrolytes is the crucial step of ASSLBs.The composite electrolyte has stable physical and electrochemical characteristics,and its comprehensive performance surpasses the individual solid electrolyte,bringing unique vitality to the solid electrolyte.However,their intrinsic weakness limits the development of composite electrolytes.In this review,we provide a comprehensive and in-depth understanding of the challenges and opportunities of composite electrolytes,with special focus on mechanisms of ion transport,nanostructure design towards high ionic conductivity,interfacial issues within electrolytes and electrodes.Furthermore,future development is prospected,which can shed light on researchers in this field and accelerate the industrial production of composite electrolytes.
基金Project(2013CB036201)supported by the National Basic Research Program of ChinaProject(51178467)supported by National Natural Science Foundation of ChinaProject(NCET-10-0839)supported by Program for New Century Excellent Talents in University,China
文摘New-old concrete composite system usually exists in concrete repairing structure.In the present work,series of experiments were carried out to investigate permeability and ion diffusion properties of new-old concrete composite by measuring 6-hour coulomb charge and chloride diffusivity.The interrelation among transport properties of new-old composites,new,and old concretes was also discussed.Results indicate that the permeability and chloride diffusivity of new-old concrete composite system closely interrelate to the corresponding new concrete and old concrete.The interfacial transition zone between new concrete and old concrete greatly influences the transport property of new-old concrete system.Compared with the corresponding new concrete and old concrete lower permeability and diffusivity values for the new-old concrete composites can be achieved by choosing suitable new concrete.It is possible to design the tailor-made new-old concrete composite system for repair given the transport property.
