Ammonium vanadate has been considered as a competitive high-performance cathode material for aqueous Zn-ion batteries.However,it still suffers from insufficient rate capability and poor cyclability due to the low elec...Ammonium vanadate has been considered as a competitive high-performance cathode material for aqueous Zn-ion batteries.However,it still suffers from insufficient rate capability and poor cyclability due to the low electronic conductivity.Herein,(NH_(4))_(2)V_(6)O_(16).0.9H_(2)Onanobelts with reduced graphene oxide(RGO)modification are synthesized by one-step hydrothermal reaction.Benefiting from the addition of RGO,an excellent electrochemical performance of(NH_(4))_(2)V_(6)O_(16).0.9H_(2)O@RGO nanobelts can be obtained.The(NH_(4))_(2)V_(6)O_(16).0.9H_(2)O@RGO displays a high-rate capacity and a high energy density of 386 Wh/kg at 72 W/kg.In particular,after 1000 cycles at 5 A/g,the capacity remains at 322 mAh/g with 92.8%capacity retention.In addition,the key reaction mechanisms of reversible Zn^(2+)insertion/extraction in(NH_(4))_(2)V_(6)O_(16).0.9H_(2)O@RGO are clarified.展开更多
The critical requirements for the environmental barrier coating(EBC)materials of silicon-based ceramic matrix composites(CMCs)include good tolerance to harsh environments,thermal expansion matches with the interlayer ...The critical requirements for the environmental barrier coating(EBC)materials of silicon-based ceramic matrix composites(CMCs)include good tolerance to harsh environments,thermal expansion matches with the interlayer mullite,good high-temperature phase stability,and low thermal conductivity.Cuspidine-structured rare-earth aluminates RE_(4)Al_(2)O_(9) have been considered as candidates of EBCs for their superior mechanical and thermal properties,but the phase transition at high temperatures is a notable drawback of these materials.To suppress the phase transition and improve the phase stability,a novel cuspidine-structured rare-earth aluminate solid solution(Nd_(0.2)Sm_(0.2)Eu_(0.2)Y_(0.2)Yb_(0.2))_(4)Al_(2)O_(9) was designed and successfully synthesized inspired by entropy stabilization effect of high-entropy ceramics(HECs).The as-synthesized HE(Nd_(0.2)Sm_(0.2)Eu_(0.2)Y_(0.2)Yb_(0.2))_(4)Al_(2)O_(9) exhibits a close thermal expansion coefficient(6.96×10^(-6) K^(-1) at 300-1473 K)to that of mullite,good phase stability from 300 to 1473 K,and low thermal conductivity(1.50 W·m^(-1)·K^(-1) at room temperature).In addition,strong anisotropic thermal expansion has been observed compared to Y_(4)Al_(2)O_(9) and Yb_(4)Al_(2)O_(9).The mechanism for low thermal conductivity is attributed to the lattice distortion and mass difference of the constituent atoms,and the anisotropic thermal expansion is due to the anisotropic chemical bonding enhanced by the large size rare-earth cations.展开更多
P-xylene(p-C_(8)H_(10))is extremely harmful and dangerous to human health due to high toxicity and strong carcinogenicity.Exploring sensitive material to effectively detect p-xylene is of importance.In this paper,pero...P-xylene(p-C_(8)H_(10))is extremely harmful and dangerous to human health due to high toxicity and strong carcinogenicity.Exploring sensitive material to effectively detect p-xylene is of importance.In this paper,perovskite single crystal(C_(4)H_(9)NH_(3))_(2)PbI_(4) has been successfully synthesized via solution method.The obtained product was analyzed by single crystal X-ray diffraction.With the space group Pbca,orthorhombic(C_(4)H_(9)NH_(3))_(2)PbI_(4) layered perovskite structure consists of an extended two-dimensional network of corner-sharing PbI_(6) octahedron.Single layer perovskite sheets of distorted PbI_(6) octahedron alternated with protonated n-butylammonium cation bilayers,which offers many advantages and provides the possibility of forming a gas sensor device based on the change of resistances.Density functional theory(DFT)simulations regarding the adsorption energy revealed that this organicinorganic hybrid perovskite compound has excellent selectivity toward p-xylene compared with other gases including C_(2)H_(5)OH,C_(6)H_(6),CH_(2)Cl_(2),HCHO,CH_(3)COCH_(3) and C_(7)H_(8).The calculation of electron density,density of states and electron density difference showed the sensing mechanism of p-C_(8)H_(10) is mainly derived from physical adsorption-desorption in view of electron transfer.展开更多
Low temperature sintered Ce_(2)Zr_(3)(Mo_(0.9)W_(0.1)O_(4))_(9)(marked as CZMW)ceramics were synthesized via the conventional solid-state reaction method.X-ray diffraction results showed that the CZMW ceramics belonge...Low temperature sintered Ce_(2)Zr_(3)(Mo_(0.9)W_(0.1)O_(4))_(9)(marked as CZMW)ceramics were synthesized via the conventional solid-state reaction method.X-ray diffraction results showed that the CZMW ceramics belonged to a Trigonal system with R-3C space group,and without any impure phase formation.The experimental facts revealed that the density and grain morphology greatly affected the microwave dielectric properties.The samples sintered at 825℃ exhibited good microwave dielectric properties.ε_(r)=9.85,Q×f=22,980 GHz(at 11.3 GHz)and a satisfactoryT_(f)(-1.5 ppm/℃)value.It is suggested that the CZMW ceramics are suitable for low-temperature co-fired ceramic(LTCC)applications in microwave devices.展开更多
Driven by safety issues,environmental concerns,and high costs,rechargeable aqueous zinc-ion batteries(ZIBs)have received increasing attention in recent years owing to their unique advantages.However,the sluggish kinet...Driven by safety issues,environmental concerns,and high costs,rechargeable aqueous zinc-ion batteries(ZIBs)have received increasing attention in recent years owing to their unique advantages.However,the sluggish kinetics of divalent charge Zn^(2+)in the cathode materials caused by the strong electrostatic interaction and their unsatisfactory cycle life hinder the development of ZIBs.Herein,organic cations and Zn^(2+)ions co-pre-inserted vanadium oxide([N(CH_(3))_(4)]_(0.77),Zn_(0.23))V_(8)O_(20)·3.8H_(2)O are reported as the cathode for ultra-stable aqueous ZIBs,in which the weaker electrostatic interactions between Zn^(2+)and organic ion-pinned vanadium oxide can induce the high reversibility of Zn^(2+)insertion and extraction,thereby improving the cycle life.It is demonstrated that([N(CH_(3))_(4)]_(0.77),Zn_(0.23))V_(8)O_(20)·3.8H_(2)O cathodes deliver a discharge capacity of 181 mA h g^(-1)at8 A g^(-1)and ultra-long life span(99.5%capacity retention after 2000 cycles).A reversible Zn^(2+)/H^(+)ions(de)intercalation storage process and pseudocapacitive charge storage are characterized.The weaker interactions between organic ion and Zn^(2+)open a novel avenue for the design of highly reversible cathode materials with long-term cycling stability.展开更多
Zinc ion hybrid supercapacitors(ZHS)have received much attention due to the enhanced potential window range and high specific capacity.However,the appropriate positive materials with high electrochemical performance a...Zinc ion hybrid supercapacitors(ZHS)have received much attention due to the enhanced potential window range and high specific capacity.However,the appropriate positive materials with high electrochemical performance are still a challenge.Herein,NH_(4)^(+)and glycerate anions pre-inserted Mo glycerate(N-MoG)spheres are synthesized and serve as the template to form NH_(4)^(+)intercalated Ni_(3)S_(2)/Ni_(3)O_(2)(OH)_(4)@MoS_(2)core–shell nanoflower(N-NiMo-OS)in-situ grown on nickel foam(NF)(N-NiMo-OS/NF)by sulfurization treatment.Compared with the product using traditional MoG as a template,N-NiMo-OS/NF inheriting a larger core structure from N-MoG delivers enhanced space for ions transport and volume expansion during the energy storage process,together with the synergistic effects of multi-components and the heterostructure,the as-prepared N-NiMo-OS/NF nanoflower exhibits excellent performance for the battery-type hybrid supercapacitors(BHS)and ZHS devices.Notably,the ZHS device delivers superior electrochemical performance to the BHS device,such as a higher specific capacity of 327.5 mAh·g^(−1)at 1 A·g^(−1),a preeminent energy density of 610.6 Wh·kg^(−1)at 1710 W·kg^(−1),long cycle life.The in-situ Raman,ex-situ X-ray photoelectron spectroscopy(XPS),theoretical calculation demonstrate the extra Zn^(2+)insertion/extraction storage mechanism provides enhanced electrochemical performance for ZHS device.Therefore,the dual-ion pre-inserted strategy can be extended for other advanced electrode materials in energy storage fields.展开更多
Flexible power sources featuring high-performance,prominent flexibility and raised safety have received mounting attention in the area of wearable electronic devices.However,many great challenges remain to be overcome...Flexible power sources featuring high-performance,prominent flexibility and raised safety have received mounting attention in the area of wearable electronic devices.However,many great challenges remain to be overcome,notably the design and fabrication of flexible electrodes with excellent electrochemical performance and matching them with safe and reliable electrolytes.Herein,a facile approach for preparing flexible electrodes,which employs carbon cloth derived from commercial cotton cloth as the substrate of cathode and a flexible anode,is proposed and investigated.The promising cathode(NVPOF@FCC)with high conductivity and outstanding flexibility is prepared by efficiently coating Na_(3)V_(2)(PO_(4))_(2)O_(2)F(NVPOF)on flexible carbon cloth(FCC),which exhibits remarkable electrochemical performance and the significantly improved reaction kinetics.More importantly,a novel flexible quasi-solid-state sodium-ion full battery(QSFB)is feasibly assembled by sandwiching a P(VDF-HFP)-NaClO_(4) gel-polymer electrolyte film between the advanced NVPOF@FCC cathode and FCC anode.And the QSFBs are further evaluated in flexible pouch cells,which not only demonstrates excellent energy-storage performance in aspect of great cycling stability and high-rate capability,but also impressive flexibility and safety.This work offers a feasible and effective strategy for the design of flexible electrodes,paving the way for the progression of practical and sustainable flexible batteries.展开更多
基金partly supported by the National Natural Science Foundation of China (No. 51772193)China Postdoctoral Science Foundation (No. 2019T120254)Hong Kong Scholar Program (No. XJ2019024)。
文摘Ammonium vanadate has been considered as a competitive high-performance cathode material for aqueous Zn-ion batteries.However,it still suffers from insufficient rate capability and poor cyclability due to the low electronic conductivity.Herein,(NH_(4))_(2)V_(6)O_(16).0.9H_(2)Onanobelts with reduced graphene oxide(RGO)modification are synthesized by one-step hydrothermal reaction.Benefiting from the addition of RGO,an excellent electrochemical performance of(NH_(4))_(2)V_(6)O_(16).0.9H_(2)O@RGO nanobelts can be obtained.The(NH_(4))_(2)V_(6)O_(16).0.9H_(2)O@RGO displays a high-rate capacity and a high energy density of 386 Wh/kg at 72 W/kg.In particular,after 1000 cycles at 5 A/g,the capacity remains at 322 mAh/g with 92.8%capacity retention.In addition,the key reaction mechanisms of reversible Zn^(2+)insertion/extraction in(NH_(4))_(2)V_(6)O_(16).0.9H_(2)O@RGO are clarified.
基金financial support from the National Natural Science Foundation of China(Grant Nos.51672064 and 51972089).
文摘The critical requirements for the environmental barrier coating(EBC)materials of silicon-based ceramic matrix composites(CMCs)include good tolerance to harsh environments,thermal expansion matches with the interlayer mullite,good high-temperature phase stability,and low thermal conductivity.Cuspidine-structured rare-earth aluminates RE_(4)Al_(2)O_(9) have been considered as candidates of EBCs for their superior mechanical and thermal properties,but the phase transition at high temperatures is a notable drawback of these materials.To suppress the phase transition and improve the phase stability,a novel cuspidine-structured rare-earth aluminate solid solution(Nd_(0.2)Sm_(0.2)Eu_(0.2)Y_(0.2)Yb_(0.2))_(4)Al_(2)O_(9) was designed and successfully synthesized inspired by entropy stabilization effect of high-entropy ceramics(HECs).The as-synthesized HE(Nd_(0.2)Sm_(0.2)Eu_(0.2)Y_(0.2)Yb_(0.2))_(4)Al_(2)O_(9) exhibits a close thermal expansion coefficient(6.96×10^(-6) K^(-1) at 300-1473 K)to that of mullite,good phase stability from 300 to 1473 K,and low thermal conductivity(1.50 W·m^(-1)·K^(-1) at room temperature).In addition,strong anisotropic thermal expansion has been observed compared to Y_(4)Al_(2)O_(9) and Yb_(4)Al_(2)O_(9).The mechanism for low thermal conductivity is attributed to the lattice distortion and mass difference of the constituent atoms,and the anisotropic thermal expansion is due to the anisotropic chemical bonding enhanced by the large size rare-earth cations.
基金financially supported by the Natural Science Foundation of Hebei(Nos.F2020202027 and F2020202067)the Major National Science and Technology Special Projects(No.2016ZX02301003-004-007)+1 种基金the National Natural Science Foundation of China(No.21271139)the Natural Science Foundation of Tianjin(No.17JCTPJC54500)。
文摘P-xylene(p-C_(8)H_(10))is extremely harmful and dangerous to human health due to high toxicity and strong carcinogenicity.Exploring sensitive material to effectively detect p-xylene is of importance.In this paper,perovskite single crystal(C_(4)H_(9)NH_(3))_(2)PbI_(4) has been successfully synthesized via solution method.The obtained product was analyzed by single crystal X-ray diffraction.With the space group Pbca,orthorhombic(C_(4)H_(9)NH_(3))_(2)PbI_(4) layered perovskite structure consists of an extended two-dimensional network of corner-sharing PbI_(6) octahedron.Single layer perovskite sheets of distorted PbI_(6) octahedron alternated with protonated n-butylammonium cation bilayers,which offers many advantages and provides the possibility of forming a gas sensor device based on the change of resistances.Density functional theory(DFT)simulations regarding the adsorption energy revealed that this organicinorganic hybrid perovskite compound has excellent selectivity toward p-xylene compared with other gases including C_(2)H_(5)OH,C_(6)H_(6),CH_(2)Cl_(2),HCHO,CH_(3)COCH_(3) and C_(7)H_(8).The calculation of electron density,density of states and electron density difference showed the sensing mechanism of p-C_(8)H_(10) is mainly derived from physical adsorption-desorption in view of electron transfer.
基金the National Natural Science Foundation of China(Grant No.51672036).
文摘Low temperature sintered Ce_(2)Zr_(3)(Mo_(0.9)W_(0.1)O_(4))_(9)(marked as CZMW)ceramics were synthesized via the conventional solid-state reaction method.X-ray diffraction results showed that the CZMW ceramics belonged to a Trigonal system with R-3C space group,and without any impure phase formation.The experimental facts revealed that the density and grain morphology greatly affected the microwave dielectric properties.The samples sintered at 825℃ exhibited good microwave dielectric properties.ε_(r)=9.85,Q×f=22,980 GHz(at 11.3 GHz)and a satisfactoryT_(f)(-1.5 ppm/℃)value.It is suggested that the CZMW ceramics are suitable for low-temperature co-fired ceramic(LTCC)applications in microwave devices.
基金supported by the funding from the National Natural Science Foundation of China(grant nos.51902187,52072224,and 51732007)the Natural Science Foundation of Shandong Province(ZR2018BEM010)+3 种基金the Science Fund for Distinguished Young Scholars of Shandong Province(ZR2019JQ16)the Fundamental Research Funds of Shandong UniversityYoung Elite Scientist Sponsorship Program by CAST(YESS)the support from Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong
文摘Driven by safety issues,environmental concerns,and high costs,rechargeable aqueous zinc-ion batteries(ZIBs)have received increasing attention in recent years owing to their unique advantages.However,the sluggish kinetics of divalent charge Zn^(2+)in the cathode materials caused by the strong electrostatic interaction and their unsatisfactory cycle life hinder the development of ZIBs.Herein,organic cations and Zn^(2+)ions co-pre-inserted vanadium oxide([N(CH_(3))_(4)]_(0.77),Zn_(0.23))V_(8)O_(20)·3.8H_(2)O are reported as the cathode for ultra-stable aqueous ZIBs,in which the weaker electrostatic interactions between Zn^(2+)and organic ion-pinned vanadium oxide can induce the high reversibility of Zn^(2+)insertion and extraction,thereby improving the cycle life.It is demonstrated that([N(CH_(3))_(4)]_(0.77),Zn_(0.23))V_(8)O_(20)·3.8H_(2)O cathodes deliver a discharge capacity of 181 mA h g^(-1)at8 A g^(-1)and ultra-long life span(99.5%capacity retention after 2000 cycles).A reversible Zn^(2+)/H^(+)ions(de)intercalation storage process and pseudocapacitive charge storage are characterized.The weaker interactions between organic ion and Zn^(2+)open a novel avenue for the design of highly reversible cathode materials with long-term cycling stability.
基金the National Natural Science Foundation of China(Nos.21702116,51772162,and 52072197)the 111 Project of China(No.D20017)+5 种基金Shandong Provincial Key Research and Development Program,China(No.2019GSF107087)Qingdao Postdoctoral Sustentation Fund,Youth Innovation and Technology Foundation of Shandong Higher Education Institutions,China(No.2019KJC004)Outstanding Youth Foundation of Shandong Province,China(No.ZR2019JQ14)Taishan Scholar Young Talent Program(No.tsqn201909114)Major Scientific and Technological Innovation Project(No.2019JZZY020405)Major Basic Research Program of Natural Science Foundation of Shandong Province(No.ZR2020ZD09).
文摘Zinc ion hybrid supercapacitors(ZHS)have received much attention due to the enhanced potential window range and high specific capacity.However,the appropriate positive materials with high electrochemical performance are still a challenge.Herein,NH_(4)^(+)and glycerate anions pre-inserted Mo glycerate(N-MoG)spheres are synthesized and serve as the template to form NH_(4)^(+)intercalated Ni_(3)S_(2)/Ni_(3)O_(2)(OH)_(4)@MoS_(2)core–shell nanoflower(N-NiMo-OS)in-situ grown on nickel foam(NF)(N-NiMo-OS/NF)by sulfurization treatment.Compared with the product using traditional MoG as a template,N-NiMo-OS/NF inheriting a larger core structure from N-MoG delivers enhanced space for ions transport and volume expansion during the energy storage process,together with the synergistic effects of multi-components and the heterostructure,the as-prepared N-NiMo-OS/NF nanoflower exhibits excellent performance for the battery-type hybrid supercapacitors(BHS)and ZHS devices.Notably,the ZHS device delivers superior electrochemical performance to the BHS device,such as a higher specific capacity of 327.5 mAh·g^(−1)at 1 A·g^(−1),a preeminent energy density of 610.6 Wh·kg^(−1)at 1710 W·kg^(−1),long cycle life.The in-situ Raman,ex-situ X-ray photoelectron spectroscopy(XPS),theoretical calculation demonstrate the extra Zn^(2+)insertion/extraction storage mechanism provides enhanced electrochemical performance for ZHS device.Therefore,the dual-ion pre-inserted strategy can be extended for other advanced electrode materials in energy storage fields.
基金supported by the National Natural Science Foundation of China(No.91963118)Science Technology Program of Jilin Province(No.20200201066JC)+2 种基金Fundamental Research Funds for the Central Universities(No.2412020QD013)China Postdoctoral Science Foundation(No.2019M661187)the National Postdoctoral Program for Innovative Talents(BX20190064).
文摘Flexible power sources featuring high-performance,prominent flexibility and raised safety have received mounting attention in the area of wearable electronic devices.However,many great challenges remain to be overcome,notably the design and fabrication of flexible electrodes with excellent electrochemical performance and matching them with safe and reliable electrolytes.Herein,a facile approach for preparing flexible electrodes,which employs carbon cloth derived from commercial cotton cloth as the substrate of cathode and a flexible anode,is proposed and investigated.The promising cathode(NVPOF@FCC)with high conductivity and outstanding flexibility is prepared by efficiently coating Na_(3)V_(2)(PO_(4))_(2)O_(2)F(NVPOF)on flexible carbon cloth(FCC),which exhibits remarkable electrochemical performance and the significantly improved reaction kinetics.More importantly,a novel flexible quasi-solid-state sodium-ion full battery(QSFB)is feasibly assembled by sandwiching a P(VDF-HFP)-NaClO_(4) gel-polymer electrolyte film between the advanced NVPOF@FCC cathode and FCC anode.And the QSFBs are further evaluated in flexible pouch cells,which not only demonstrates excellent energy-storage performance in aspect of great cycling stability and high-rate capability,but also impressive flexibility and safety.This work offers a feasible and effective strategy for the design of flexible electrodes,paving the way for the progression of practical and sustainable flexible batteries.
