Solid-state polymer electrolytes hold the potential for market application due to the combination of advantageous properties,such as flexibility,ease of processing and low cost.However,the sluggish ion transport and p...Solid-state polymer electrolytes hold the potential for market application due to the combination of advantageous properties,such as flexibility,ease of processing and low cost.However,the sluggish ion transport and poor high-voltage stability pose significant challenges for the practical application of polymer-based solid-state lithium metal batteries(SSLMBs).Therefore,the design and development of polymer-based SSLMBs toward fast-charge and high-voltage is of great significance in high-energydensity devices.Herein,this review deeply analyzes the mechanism of ion transport and anti-oxidation of polymer-based solidstate electrolytes.Furthermore,we also systematically and comprehensively summarize the factors that affect ionic conductivity and the electrochemical window.Moreover,we outline the solution strategies for simultaneously enhancing both ionic conductivity and high-voltage stability.Besides,we discuss the main challenges and the future prospects of polymer-based SSLMBs for further studies.It is hoped that this review can provide both advances and fundamentals to the research community and pave the way for the development of SSLMBs.展开更多
Molten salts serve as primary heat transfer and storage media in thermal energy storage systems.Adding nanoparticles to molten salt to create nanofluids is known to significantly improve the thermal conductivity of th...Molten salts serve as primary heat transfer and storage media in thermal energy storage systems.Adding nanoparticles to molten salt to create nanofluids is known to significantly improve the thermal conductivity of the molten salts.However,nanoparticle agglomeration is inevitable and substantially affects the thermal con-ductivity of molten salts.Moreover,the mechanisms whereby agglomeration influences thermal conductivity remain unclear.This paper presents an innovative multiscale coupling model that combines molecular dynamics(MD)simulations with the lattice Boltzmann method(LBM)to investigate the thermal conductivity of CuO nanoparticles in ternary NaCl-KCl-LiCl molten salt-based nanofluids.Both nonaggregated and aggregated states were considered.After conducting MD simulations at the microscale to examine the thermal contact resistance at the interface between nanoparticles,we employed the LBM to determine the effective thermal conductivity of the nanofluids at the mesoscale.The findings reveal the formation of significant heat flow channels in nanofluids containing nanoparticles.However,an increase in the thermal contact resistance reduces these channels in agglomerated particles,potentially reducing the thermal conductivity compared with that in the nonaggregated nanofluids.In cluster-like structures,fewer nanoparticles are positioned within heat flow channels,in contrast to chain-like arrangements.This reduction limits the enhancement in the thermal conductivity and minimizes variations in the thermal conductivity due to differences in the aggregate particle number and orientation.Furthermore,the thermal conductivity exhibited notable variations with varying agglomerated nanoparticle diameters at identical mass fractions.Both smaller and larger particles can increase the level of contact thermal resistance,ultimately reducing the thermal conductivity.展开更多
The environmental repercussions of wastewater from the dye process mean that it is very important to obtain an eco-friendly photocatalyst that would degrade wastewater.Herein,bismuth tungstate/graphene oxide(Bi_(2)WO_...The environmental repercussions of wastewater from the dye process mean that it is very important to obtain an eco-friendly photocatalyst that would degrade wastewater.Herein,bismuth tungstate/graphene oxide(Bi_(2)WO_(6)/GO)composites are fabricated through in-situ hydrothermal reaction and then the Bi_(2)WO_(6)/GO photocatalysts are deposited onto polyethylene terephthalate(PET)fabric.The obtained Bi_(2)WO_(6)/GO deposited PET fabrics are then characterized through XPS,Raman,SEM,TEM,XRD,UV-vis,BET method and photoluminescence spectroscopy(PL)to investigate their chemical and crystal structures,morphology,optical property,surface area and photochemical properties.Photocatalytic performance is studied through examining the rate of degrading rhodamine B(RhB)under visible light.Surface of PET fibers is densely covered with Bi_(2)WO_(6)/GO.Bi_(2)WO_(6)/GO deposited PET fabrics show a broad absorption band in the visible spectra.Removal rate of RhB on the Bi_(2)WO_(6)/GO deposited PET fabric is the highest with the GO content of 2 g/L(labeled as Bi_(2)WO_(6)/2 g/LGO).The result of active species experiment shows that superoxide radicals(·O_(2)^(−))plays a major role in the degradation of RhB.Moreover,Bi_(2)WO_(6)/2 g/LGO deposited PET fabric shows excellent cycle stability of photocatalytic degradation for RhB.The findings in this work can be extended to preparation other types of composite on the textile for photocatalysis,which can be applied to remove dyes in the wastewater produced by the textile or leather industry.展开更多
The problems of electromagnetic wave(EMW)pollution in X and Ku bands(8–18 GHz)are becoming more and more serious.Therefore,it is urgent to design EMW absorbing materials with high-efficiency such as thin thickness,li...The problems of electromagnetic wave(EMW)pollution in X and Ku bands(8–18 GHz)are becoming more and more serious.Therefore,it is urgent to design EMW absorbing materials with high-efficiency such as thin thickness,lightweight,wide bandwidth and strong EMW absorption.Inspired by the biomorph of sea cucumber,Nb_(2)CT_(x) MXene@Co nitrogen-doped carbon nanosheet arrays@carbon fiber aerogels(Nb_(2)CT_(x)@Co-NC@CFA,Nb_(2)CT_(x)=niobium carbide)were constructed by self-assembly,in-situ chemical deposition and subsequent pyrolysis.The carbon fiber aerogel,as the basic skeleton of sea cucumber,forms lightweight three-dimensional interconnected conductive network,enhances the dielectric loss and extends the multiple reflection and absorption paths of EMW.As the tentacles of sea cucumber surface,Nb_(2)CT_(x) MXene and Co nitrogen-doped carbon nanosheet arrays exist rich heterogeneous interfaces,which play an important role in improving EMW polarization loss and optimizing impedance matching.The minimum reflection loss(RLmin)of Nb_(2)CT_(x)@Co-NC@CFA reaches−54.7 dB at 9.84 GHz(2.36 mm)with a low filling ratio of 10 wt.%and the effective absorption bandwidth(EAB)of Nb_(2)CT_(x)@Co-NC@CFA reaches 2.96 GHz(8.48–11.44 GHz)with 2.36 mm and 5.2 GHz(12.8–18 GHz)with 1.6 mm,covering most of X and Ku bands by adjusting thickness.The radar cross section(RCS)value of Nb_(2)CT_(x)@Co-NC@CFA is 26.64 dB·m^(2),which is lower than that of the perfect electrical conductor(PEC),indicating that Nb_(2)CT_(x)@Co-NC@CFA can effectively decrease the probability of the target being detected by the radar detector.This work provides ideas for design and development of EMW absorbing materials with high-efficiency EMW absorption in X and Ku bands.展开更多
基金supported by the National Natural Science Foundation of China(22272058,22072048)the Key Technologies R&D Program of Guangdong Province(2023B0909060003)the Guangdong Basic and Applied Basic Research Foundation(2022A1515111097)。
文摘Solid-state polymer electrolytes hold the potential for market application due to the combination of advantageous properties,such as flexibility,ease of processing and low cost.However,the sluggish ion transport and poor high-voltage stability pose significant challenges for the practical application of polymer-based solid-state lithium metal batteries(SSLMBs).Therefore,the design and development of polymer-based SSLMBs toward fast-charge and high-voltage is of great significance in high-energydensity devices.Herein,this review deeply analyzes the mechanism of ion transport and anti-oxidation of polymer-based solidstate electrolytes.Furthermore,we also systematically and comprehensively summarize the factors that affect ionic conductivity and the electrochemical window.Moreover,we outline the solution strategies for simultaneously enhancing both ionic conductivity and high-voltage stability.Besides,we discuss the main challenges and the future prospects of polymer-based SSLMBs for further studies.It is hoped that this review can provide both advances and fundamentals to the research community and pave the way for the development of SSLMBs.
基金financial support from the National Key Research and Development Program of China-National Quality Infra-structure System(Grant No.:2023YFF0615001)the Postdoctoral Fellowship Program of CPSF(Grant No.:GZC20241346).
文摘Molten salts serve as primary heat transfer and storage media in thermal energy storage systems.Adding nanoparticles to molten salt to create nanofluids is known to significantly improve the thermal conductivity of the molten salts.However,nanoparticle agglomeration is inevitable and substantially affects the thermal con-ductivity of molten salts.Moreover,the mechanisms whereby agglomeration influences thermal conductivity remain unclear.This paper presents an innovative multiscale coupling model that combines molecular dynamics(MD)simulations with the lattice Boltzmann method(LBM)to investigate the thermal conductivity of CuO nanoparticles in ternary NaCl-KCl-LiCl molten salt-based nanofluids.Both nonaggregated and aggregated states were considered.After conducting MD simulations at the microscale to examine the thermal contact resistance at the interface between nanoparticles,we employed the LBM to determine the effective thermal conductivity of the nanofluids at the mesoscale.The findings reveal the formation of significant heat flow channels in nanofluids containing nanoparticles.However,an increase in the thermal contact resistance reduces these channels in agglomerated particles,potentially reducing the thermal conductivity compared with that in the nonaggregated nanofluids.In cluster-like structures,fewer nanoparticles are positioned within heat flow channels,in contrast to chain-like arrangements.This reduction limits the enhancement in the thermal conductivity and minimizes variations in the thermal conductivity due to differences in the aggregate particle number and orientation.Furthermore,the thermal conductivity exhibited notable variations with varying agglomerated nanoparticle diameters at identical mass fractions.Both smaller and larger particles can increase the level of contact thermal resistance,ultimately reducing the thermal conductivity.
基金Joint Fund of the National Natural Science Foundation of China(No.U1833118)Sichuan Science and Technology Program(2019YFG0244).
文摘The environmental repercussions of wastewater from the dye process mean that it is very important to obtain an eco-friendly photocatalyst that would degrade wastewater.Herein,bismuth tungstate/graphene oxide(Bi_(2)WO_(6)/GO)composites are fabricated through in-situ hydrothermal reaction and then the Bi_(2)WO_(6)/GO photocatalysts are deposited onto polyethylene terephthalate(PET)fabric.The obtained Bi_(2)WO_(6)/GO deposited PET fabrics are then characterized through XPS,Raman,SEM,TEM,XRD,UV-vis,BET method and photoluminescence spectroscopy(PL)to investigate their chemical and crystal structures,morphology,optical property,surface area and photochemical properties.Photocatalytic performance is studied through examining the rate of degrading rhodamine B(RhB)under visible light.Surface of PET fibers is densely covered with Bi_(2)WO_(6)/GO.Bi_(2)WO_(6)/GO deposited PET fabrics show a broad absorption band in the visible spectra.Removal rate of RhB on the Bi_(2)WO_(6)/GO deposited PET fabric is the highest with the GO content of 2 g/L(labeled as Bi_(2)WO_(6)/2 g/LGO).The result of active species experiment shows that superoxide radicals(·O_(2)^(−))plays a major role in the degradation of RhB.Moreover,Bi_(2)WO_(6)/2 g/LGO deposited PET fabric shows excellent cycle stability of photocatalytic degradation for RhB.The findings in this work can be extended to preparation other types of composite on the textile for photocatalysis,which can be applied to remove dyes in the wastewater produced by the textile or leather industry.
基金financially supported by the National Natural Science Foundation of China and the Civil Aviation Administration of China(No.U1833118)the Open Project Program of High-Tech Organic Fibers Key Laboratory of Sichuan Province(No.PLN2022-10)+3 种基金the Science and Technology Plan Project of Chengdu City(2022-YF05-00411-SN)Science and Technology Planning Project of Sichuan Province(Nos.2023YFQ0090,2024YFHZ0218,2023YFN0016,and 2023YFQ083)Yibin Science and Technology Plan Project(No.2022JB013)Engineering characteristic team of Sichuan University(No.2020SCUNG122).
文摘The problems of electromagnetic wave(EMW)pollution in X and Ku bands(8–18 GHz)are becoming more and more serious.Therefore,it is urgent to design EMW absorbing materials with high-efficiency such as thin thickness,lightweight,wide bandwidth and strong EMW absorption.Inspired by the biomorph of sea cucumber,Nb_(2)CT_(x) MXene@Co nitrogen-doped carbon nanosheet arrays@carbon fiber aerogels(Nb_(2)CT_(x)@Co-NC@CFA,Nb_(2)CT_(x)=niobium carbide)were constructed by self-assembly,in-situ chemical deposition and subsequent pyrolysis.The carbon fiber aerogel,as the basic skeleton of sea cucumber,forms lightweight three-dimensional interconnected conductive network,enhances the dielectric loss and extends the multiple reflection and absorption paths of EMW.As the tentacles of sea cucumber surface,Nb_(2)CT_(x) MXene and Co nitrogen-doped carbon nanosheet arrays exist rich heterogeneous interfaces,which play an important role in improving EMW polarization loss and optimizing impedance matching.The minimum reflection loss(RLmin)of Nb_(2)CT_(x)@Co-NC@CFA reaches−54.7 dB at 9.84 GHz(2.36 mm)with a low filling ratio of 10 wt.%and the effective absorption bandwidth(EAB)of Nb_(2)CT_(x)@Co-NC@CFA reaches 2.96 GHz(8.48–11.44 GHz)with 2.36 mm and 5.2 GHz(12.8–18 GHz)with 1.6 mm,covering most of X and Ku bands by adjusting thickness.The radar cross section(RCS)value of Nb_(2)CT_(x)@Co-NC@CFA is 26.64 dB·m^(2),which is lower than that of the perfect electrical conductor(PEC),indicating that Nb_(2)CT_(x)@Co-NC@CFA can effectively decrease the probability of the target being detected by the radar detector.This work provides ideas for design and development of EMW absorbing materials with high-efficiency EMW absorption in X and Ku bands.
