The phosphors of （Bi1- x Smx ） 2ZnB2O7 （ x = 0. 01, 0. 03, 0. 05, 0. 07, and 0. 09） were synthesized by conventional solid state reaction. The purity of all samples was checked by X-ray powder diffraction （XRD）....The phosphors of （Bi1- x Smx ） 2ZnB2O7 （ x = 0. 01, 0. 03, 0. 05, 0. 07, and 0. 09） were synthesized by conventional solid state reaction. The purity of all samples was checked by X-ray powder diffraction （XRD）. XRD analysis shows that all these compounds are of a single phase of Bi2ZnB2O7, indicating that the Bi^3＋ in Bi2ZnB2O7 can be partly replaced by the Sm^3＋ without the change of crystal structure. The excitation and emission spectra at room temperature show the typical 4f-4f transitions of Sm^3＋ . The dominant excitation line is around 404 nm due to ^6H5/2→^4K11/2 and the emission spectrum consists of a series of lines at 563, 599, 646, and 704 nm due to ^4G5/2→^6H5/2, ^6H7/2, ^6H9/2, and ^6H11/2, respectively. The optimal concentration of Sm^3＋ in Bi2ZnB2O7 is about 3mol% （relative to lmol Bi^3＋ ） and the critical distance Rc was calculated as 2.1 nm. The temperature dependence of the emission intensity of Bi1.94Sm0.06ZnB2O7 was examined in the temperature range between 100 and 450 K. The quenching temperature where the intensity has dropped to half of the initial intensity is 280 K. The lifetime for Sm^3＋ in Bi1.94Sm0.06ZnB2O7 is fitted as a value of 0.29 and 1.03 ms.展开更多
Sodium with low cost and high abundance is considered as a substitute element of lithium for batteries and supercapacitors,which need the appropriate host materials to accommodate the relatively large Na^(+) ions.Comp...Sodium with low cost and high abundance is considered as a substitute element of lithium for batteries and supercapacitors,which need the appropriate host materials to accommodate the relatively large Na^(+) ions.Compared to Li^(+) storage,Na^(+) storage makes higher demands on the structural optimization of perovskite bismuth ferrite(BiFeO_(3)).We propose a novel strategy of defect engineering on BiFeO_(3) through Na and V codoping for high-efficiency Na^(+) storage,to reveal the roles of oxygen vacancies and V ions played in the enhanced electrochemical energy storage performances of Na-ion capacitors.The formation of the oxygen vacancies in the Na and V codoped BiFeO_(3)(denoted as NV-BFO),is promoted by Na doping and suppressed by V doping,which can be demonstrated by XPS and EPR spectra.By the first-principles calculations,the oxygen vacancies and V ions in NV-BFO are confirmed to substantially lower the Na^(+)migration energy barriers through the space and electric field effects,to effectively promote the Na^(+) transport in the crystals.Electrochemical kinetic analysis of the NV-BFO//NV-BFO capacitors indicates the dominant capacitive-controlled capacity,which depends on fast Na^(+) deintercalation-intercalation process in the NV-BFO electrode.The NV-BFO//NV-BFO capacitors open up a new avenue for developing highperformance Na-ion capacitors.展开更多
Solid-state electrolytes with high oxidation stability are crucial for achieving high power density allsolid-state lithium batteries.Halide electrolytes are promising candidates due to their outstanding compatibility ...Solid-state electrolytes with high oxidation stability are crucial for achieving high power density allsolid-state lithium batteries.Halide electrolytes are promising candidates due to their outstanding compatibility with cathode materials and high Li^(+)conductivity.However,the electrochemical stability of chloride electrolytes is still limited,leaving them unsuitable for ultrahigh voltage operation.Besides,chemical compatibility issue between sulfide and halide electrolytes affects the electrochemical performance of all-solid-state batteries.Herein,Li-ion conductor Li_(3+x)InCl_(6-x)O_(x) is designed to address these challenges.Li_(3.25)InCl_(5.75)O_(0.25)shows a Li-ion conductivity of 0.90 mS cm^(-1)at room temperature,a high onset oxidation voltage of 3.84 V,fewer by-products at ultrahigh operation voltage,and good chemical compatibility with Li_(5.5)PS_(4.5)Cl_(1.5).The Li_(3.25)InCl_(5.75)O_(0.25)@LiNi_(0.7)Co_(0.1)Mn_(0.2)O_(2)-Li_(3.25)InCl_(5.75)O_(0.25)-VGCF/Li_(3.25)InCl_(5.75)O_(0.25)/Li_(5.5)PS_(4.5)Cl_(1.5)/Li-In battery delivers good electrochemical performances at high operating voltage.This work provides a simple,economical,and effective strategy for designing high-voltage all-solid-state electrolytes.展开更多
Potassium-ion batteries(PIBs)offer a cost-effective and resource-abundant solution for large-scale energy storage.However,the progress of PIBs is impeded by the lack of high-capacity,long-life,and fast-kinetics anode ...Potassium-ion batteries(PIBs)offer a cost-effective and resource-abundant solution for large-scale energy storage.However,the progress of PIBs is impeded by the lack of high-capacity,long-life,and fast-kinetics anode electrode materials.Here,we propose a dual synergic optimization strategy to enhance the K^(+)storage stability and reaction kinetics of Bi_(2)S_(3) through two-dimensional compositing and cation doping.Externally,Bi_(2)S_(3) nanoparticles are loaded onto the surface of three-dimensional interconnected Ti_(3)C_(2)T_(x) nanosheets to stabilize the electrode structure.Internally,Cu^(2+)doping acts as active sites to accelerate K^(+)storage kinetics.Various theoretical simulations and ex situ techniques are used to elucidate the external–internal dual synergism.During discharge,Ti_(3)C_(2)T_(x) and Cu^(2+)collaboratively facilitate K+intercalation.Subsequently,Cu^(2+)doping primarily promotes the fracture of Bi2S3 bonds,facilitating a conversion reaction.Throughout cycling,the Ti_(3)C_(2)T_(x) composite structure and Cu^(2+)doping sustain functionality.The resulting Cu^(2+)-doped Bi2S3 anchored on Ti_(3)C_(2)T_(x)(C-BT)shows excellent rate capability(600 mAh g^(-1) at 0.1 A g^(–1);105 mAh g^(-1) at 5.0 A g^(-1))and cycling performance(91 mAh g^(-1) at 5.0 A g^(-1) after 1000 cycles)in half cells and a high energy density(179 Wh kg–1)in full cells.展开更多
The combined effects of Sm^(3+)substitution together with the addition of 3 wt%Bi_(2)O_(3)endow Mg Cd ferrites with excellent magnetic permeability and dielectric permittivity.Various concentrations of Sm^(3+)(x=0,0.0...The combined effects of Sm^(3+)substitution together with the addition of 3 wt%Bi_(2)O_(3)endow Mg Cd ferrites with excellent magnetic permeability and dielectric permittivity.Various concentrations of Sm^(3+)(x=0,0.03,0.06,0.09,0.12and 0.15)were employed to modify the permeability(μ)and permittivity(ε)of the Mg Cd ferrites.X-ray diffraction,scanning electron microscopy(SEM),vibrating sample magnetometry and vector network analysis techniques were used to characterize the samples.The measurement results reveal that the ferrites processed a saturation magnetization of up to 36.8 emu/g and coercivity of up to 29.2 Oe via the conventional solid-state reaction method.The surface morphology SEM confirms that with increasing Sm^(3+)concentration,the grain shape changes from a polygon to a circle.Moreover,the dielectric permittivity can reach a value of 23.The excellent properties obtained in Sm^(3+)-substituted Mg ferrites suggest that they could be promising candidates for modern high-frequency antenna substrates or multilayer devices.展开更多
A series of SrIn2 O4 ：Eu^3＋ phosphors are synthesized by a high temperature solid-state method, and their luminescent properties are investigated. They can be excited by 395-nm radiation, and produce red emission （...A series of SrIn2 O4 ：Eu^3＋ phosphors are synthesized by a high temperature solid-state method, and their luminescent properties are investigated. They can be excited by 395-nm radiation, and produce red emission （619 nm）; however, they have a low absorption of near-ultraviolet light with the wavelength of 400nm–405 nm. When co-doped with A^＋ （A=Li, Na, K）, the emission intensity of SrIn2O4 ：Eu^3＋ is significantly enhanced, but its emission and excitation spectral profile is unchanged. With co-doping Sm^3＋ , not only is the emission intensity of SrIn2 O4 ：Eu^3＋ enhanced, but also the absorption is broadened and strengthened in the range of 400 nm–405nm. The effect of Sm^3＋ -doped content on the emission intensity of SrIn2O4 ：Eu^3＋ , Sm^3＋ is investigated, and the optimal Sm^3＋ content is 0.02 mol.展开更多
基金Project supported by the National Natural Science Foundation of China (20501023) and the Guangdong Provincial NaturalScience Foundation (5300527)
文摘The phosphors of （Bi1- x Smx ） 2ZnB2O7 （ x = 0. 01, 0. 03, 0. 05, 0. 07, and 0. 09） were synthesized by conventional solid state reaction. The purity of all samples was checked by X-ray powder diffraction （XRD）. XRD analysis shows that all these compounds are of a single phase of Bi2ZnB2O7, indicating that the Bi^3＋ in Bi2ZnB2O7 can be partly replaced by the Sm^3＋ without the change of crystal structure. The excitation and emission spectra at room temperature show the typical 4f-4f transitions of Sm^3＋ . The dominant excitation line is around 404 nm due to ^6H5/2→^4K11/2 and the emission spectrum consists of a series of lines at 563, 599, 646, and 704 nm due to ^4G5/2→^6H5/2, ^6H7/2, ^6H9/2, and ^6H11/2, respectively. The optimal concentration of Sm^3＋ in Bi2ZnB2O7 is about 3mol% （relative to lmol Bi^3＋ ） and the critical distance Rc was calculated as 2.1 nm. The temperature dependence of the emission intensity of Bi1.94Sm0.06ZnB2O7 was examined in the temperature range between 100 and 450 K. The quenching temperature where the intensity has dropped to half of the initial intensity is 280 K. The lifetime for Sm^3＋ in Bi1.94Sm0.06ZnB2O7 is fitted as a value of 0.29 and 1.03 ms.
基金financial supports from National Natural Science Foundation of China(22005174 and 52271133)。
文摘Sodium with low cost and high abundance is considered as a substitute element of lithium for batteries and supercapacitors,which need the appropriate host materials to accommodate the relatively large Na^(+) ions.Compared to Li^(+) storage,Na^(+) storage makes higher demands on the structural optimization of perovskite bismuth ferrite(BiFeO_(3)).We propose a novel strategy of defect engineering on BiFeO_(3) through Na and V codoping for high-efficiency Na^(+) storage,to reveal the roles of oxygen vacancies and V ions played in the enhanced electrochemical energy storage performances of Na-ion capacitors.The formation of the oxygen vacancies in the Na and V codoped BiFeO_(3)(denoted as NV-BFO),is promoted by Na doping and suppressed by V doping,which can be demonstrated by XPS and EPR spectra.By the first-principles calculations,the oxygen vacancies and V ions in NV-BFO are confirmed to substantially lower the Na^(+)migration energy barriers through the space and electric field effects,to effectively promote the Na^(+) transport in the crystals.Electrochemical kinetic analysis of the NV-BFO//NV-BFO capacitors indicates the dominant capacitive-controlled capacity,which depends on fast Na^(+) deintercalation-intercalation process in the NV-BFO electrode.The NV-BFO//NV-BFO capacitors open up a new avenue for developing highperformance Na-ion capacitors.
基金supported by the National Key Research and Development Program of China(2021YFB2500200)the National Natural Science Foundation of China(52177214,52222703)for supporting our workJiangsu Funding Program for Excellent Postdoctoral Talent for the support。
文摘Solid-state electrolytes with high oxidation stability are crucial for achieving high power density allsolid-state lithium batteries.Halide electrolytes are promising candidates due to their outstanding compatibility with cathode materials and high Li^(+)conductivity.However,the electrochemical stability of chloride electrolytes is still limited,leaving them unsuitable for ultrahigh voltage operation.Besides,chemical compatibility issue between sulfide and halide electrolytes affects the electrochemical performance of all-solid-state batteries.Herein,Li-ion conductor Li_(3+x)InCl_(6-x)O_(x) is designed to address these challenges.Li_(3.25)InCl_(5.75)O_(0.25)shows a Li-ion conductivity of 0.90 mS cm^(-1)at room temperature,a high onset oxidation voltage of 3.84 V,fewer by-products at ultrahigh operation voltage,and good chemical compatibility with Li_(5.5)PS_(4.5)Cl_(1.5).The Li_(3.25)InCl_(5.75)O_(0.25)@LiNi_(0.7)Co_(0.1)Mn_(0.2)O_(2)-Li_(3.25)InCl_(5.75)O_(0.25)-VGCF/Li_(3.25)InCl_(5.75)O_(0.25)/Li_(5.5)PS_(4.5)Cl_(1.5)/Li-In battery delivers good electrochemical performances at high operating voltage.This work provides a simple,economical,and effective strategy for designing high-voltage all-solid-state electrolytes.
基金This work received financial support from the National Natural Science Foundation of China(Grant Nos.U23A20574,52250010,and 52201242)the 261 Project MIIT,the Young Elite Scientists Sponsorship Program by CAST(Grant No.2021QNRC001)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.2242022R40018)the Jiangsu Funding Program for Excellent Postdoctoral Talent(Grant No.2022ZB75).
文摘Potassium-ion batteries(PIBs)offer a cost-effective and resource-abundant solution for large-scale energy storage.However,the progress of PIBs is impeded by the lack of high-capacity,long-life,and fast-kinetics anode electrode materials.Here,we propose a dual synergic optimization strategy to enhance the K^(+)storage stability and reaction kinetics of Bi_(2)S_(3) through two-dimensional compositing and cation doping.Externally,Bi_(2)S_(3) nanoparticles are loaded onto the surface of three-dimensional interconnected Ti_(3)C_(2)T_(x) nanosheets to stabilize the electrode structure.Internally,Cu^(2+)doping acts as active sites to accelerate K^(+)storage kinetics.Various theoretical simulations and ex situ techniques are used to elucidate the external–internal dual synergism.During discharge,Ti_(3)C_(2)T_(x) and Cu^(2+)collaboratively facilitate K+intercalation.Subsequently,Cu^(2+)doping primarily promotes the fracture of Bi2S3 bonds,facilitating a conversion reaction.Throughout cycling,the Ti_(3)C_(2)T_(x) composite structure and Cu^(2+)doping sustain functionality.The resulting Cu^(2+)-doped Bi2S3 anchored on Ti_(3)C_(2)T_(x)(C-BT)shows excellent rate capability(600 mAh g^(-1) at 0.1 A g^(–1);105 mAh g^(-1) at 5.0 A g^(-1))and cycling performance(91 mAh g^(-1) at 5.0 A g^(-1) after 1000 cycles)in half cells and a high energy density(179 Wh kg–1)in full cells.
基金the National Key Research and Development Program of China(Grant No.2018YFE0115500)the National Natural Science Foundation of China(Grant Nos.51902037 and 62005033)+2 种基金the Open Foundation of State Key Laboratory of Electronic Thin Films and Integrated Devices(Grant No.KFJJ201912)the Science and Technology Project Affiliated to the Education Department of Chongqing Municipality(Grant No.KJQN201900615)the Nature Science Foundation of Chongqing(Grant No.cstc2019jcyjmsxm X0696)。
文摘The combined effects of Sm^(3+)substitution together with the addition of 3 wt%Bi_(2)O_(3)endow Mg Cd ferrites with excellent magnetic permeability and dielectric permittivity.Various concentrations of Sm^(3+)(x=0,0.03,0.06,0.09,0.12and 0.15)were employed to modify the permeability(μ)and permittivity(ε)of the Mg Cd ferrites.X-ray diffraction,scanning electron microscopy(SEM),vibrating sample magnetometry and vector network analysis techniques were used to characterize the samples.The measurement results reveal that the ferrites processed a saturation magnetization of up to 36.8 emu/g and coercivity of up to 29.2 Oe via the conventional solid-state reaction method.The surface morphology SEM confirms that with increasing Sm^(3+)concentration,the grain shape changes from a polygon to a circle.Moreover,the dielectric permittivity can reach a value of 23.The excellent properties obtained in Sm^(3+)-substituted Mg ferrites suggest that they could be promising candidates for modern high-frequency antenna substrates or multilayer devices.
基金Project supported by the National Natural Science Foundation of China (Grant No. 50902042)the Natural Science Foundation of Hebei Province, China(Grant Nos. E2009000209 and E2010000283)+1 种基金the Education Bureau Foundation of Hebei Province, China (Grant No. 2009313)the Key Laboratory of Luminescence and Optical Information, Beijing Jiaotong University, Ministry of Education, China (Grant No. 2010LOI12)
文摘A series of SrIn2 O4 ：Eu^3＋ phosphors are synthesized by a high temperature solid-state method, and their luminescent properties are investigated. They can be excited by 395-nm radiation, and produce red emission （619 nm）; however, they have a low absorption of near-ultraviolet light with the wavelength of 400nm–405 nm. When co-doped with A^＋ （A=Li, Na, K）, the emission intensity of SrIn2O4 ：Eu^3＋ is significantly enhanced, but its emission and excitation spectral profile is unchanged. With co-doping Sm^3＋ , not only is the emission intensity of SrIn2 O4 ：Eu^3＋ enhanced, but also the absorption is broadened and strengthened in the range of 400 nm–405nm. The effect of Sm^3＋ -doped content on the emission intensity of SrIn2O4 ：Eu^3＋ , Sm^3＋ is investigated, and the optimal Sm^3＋ content is 0.02 mol.
