Aqueous zinc ion batteries show prospects for next-generation renewable energy storage devices.However,the practical applications have been limited by the issues derived from Zn anode.As one of serious problems,Zn den...Aqueous zinc ion batteries show prospects for next-generation renewable energy storage devices.However,the practical applications have been limited by the issues derived from Zn anode.As one of serious problems,Zn dendrite growth caused from the uncontrollable Zn deposition is unfavorable.Herein,with the aim to regulate Zn deposition,an artificial solid–electrolyte interface is subtly engineered with a perovskite type material,BaTiO3,which can be polarized,and its polarization could be switched under the external electric field.Resulting from the aligned dipole in BaTiO3 layer,zinc ions could move in order during cycling process.Regulated Zn migration at the anode/electrolyte interface contributes to the even Zn stripping/plating and confined Zn dendrite growth.As a result,the reversible Zn plating/stripping processes for over 2000 h have been achieved at 1 mA cm^(−2) with capacity of 1 mAh cm−2.Furthermore,this anode endowing the electric dipoles shows enhanced cycling stability for aqueous Zn-MnO2 batteries.The battery can deliver nearly 100%Coulombic efficiency at 2 Ag^(−1) after 300 cycles.展开更多
为克服固体介质内空间电荷和电导分立测量导致实验数据关联性弱的缺陷,基于电声脉冲法原理设计了一套片状试样空间电荷和电导同步测量系统,以获得同片试样在不同电场下的空间电荷和电导动态响应。首先,通过空间电荷测量中电脉冲响应的...为克服固体介质内空间电荷和电导分立测量导致实验数据关联性弱的缺陷,基于电声脉冲法原理设计了一套片状试样空间电荷和电导同步测量系统,以获得同片试样在不同电场下的空间电荷和电导动态响应。首先,通过空间电荷测量中电脉冲响应的仿真计算,分析了电脉冲对同步测量时电导的干扰,并采用空间电荷和电导快速分时切换测量的模式解决电脉冲干扰。然后,基于IEC/TS62758-2012空间电荷测量技术校验规范,采用有机玻璃试样对该系统进行了系统验证,以评估空间电荷测量的准确性。最后,采用该系统对低密度聚乙烯(low density polyethylene-LDPE)试样在室温下进行了不同电场时的空间电荷和电导的同步测量,并根据空间电荷时空分布信息计算出位移电流和传导电流分布。结果表明:高(50kV/mm)电场下,半导电/LDPE试样/铝测量结构中LDPE内的位移电流明显低于传导电流,且传导电流的载流子主要源于电极的表面注入,杂质在高场下的解离对传导电流影响不明显。展开更多
Pressure wave propagation (PWP) method was utilized to observe the space charges packet-like behavior in sheet samples of low-density polyethylene (LDPE) under the relative low electric field. The experimental results...Pressure wave propagation (PWP) method was utilized to observe the space charges packet-like behavior in sheet samples of low-density polyethylene (LDPE) under the relative low electric field. The experimental results show that space charge packets are always generated at the anode and move across the sample to the cathode regardless of the polarity of DC voltage. This paper discusses the migration of space charge packets at 30–40°C, the possible charge resource of space charge packets carriers and trap level of the space charge.展开更多
With the help of the first principle calculation,the solid-state reaction experiment was conducted to investigate the alteration in the sintering and the microwave dielectric properties of Mg_(3)B_(2)O_(6)ceramic with...With the help of the first principle calculation,the solid-state reaction experiment was conducted to investigate the alteration in the sintering and the microwave dielectric properties of Mg_(3)B_(2)O_(6)ceramic with many Zn^(2+)substitutions.These properties were characterized using the scanning electron microscopy,network analyzer,X-ray diffraction,Raman spectroscopy,energy-dispersive spectroscopy,and thermomechanical and differential-thermal analyses.The coexistence of Mg_(3)B_(2)O_(6),Mg_(2)B_(2)O_(5)and ZnO ceramics could be observed with increasing Zn^(2+)addition,and the lattice distortion occurred in the Mg_(2)B_(2)O_(5)and Mg_(3)B_(2)O_(6)ceramics due to the substitution of Mg^(2+)with Zn^(2+).The electron density and the bond property of the MgO_(6)octahedron changed,and a quantitative method was used to discuss the variation in sintering,substitution and phase formation properties.The densification window was decreased to 1100℃,and the dielectric properties improved with the formation of a three-phase borate solid solution(dielectric constant=6.73,quality factor=112,000 GHz at 16 GHz(Q=7000),temperature coefficient of resonant frequency=-61.2 ppm℃^(-1),and relative density=97.0%).展开更多
Accompanied by solid-state structural phase transitions,the switchable molecular dynamics(MD)and order-disorder transformation of(i-PrNHMe2)^(+)cation embedded in a deformable{[Ni(NCS)_(6)]^(4-)}_(∞)supramolecular fr...Accompanied by solid-state structural phase transitions,the switchable molecular dynamics(MD)and order-disorder transformation of(i-PrNHMe2)^(+)cation embedded in a deformable{[Ni(NCS)_(6)]^(4-)}_(∞)supramolecular framework are in-depth investigated by variable-temperature tests of single-crystal X-ray diffraction,dielectric measurement,and MD simulation.Interestingly,it is found that the confined swinging or flipping of the(i-PrNHMe_(2))^(+)cation as a whole is assisted by a synergistic change of its torsion angle.This research provides a helpful insight into the solid-state MD of moderate-sized quasi-spherical molecules/ions that feature a flexible inner core.展开更多
Structural and various electrical properties of polycrystalline Ca0.5＋xNd0,5-x（Ti0.5Fe0.5）O3, prepared by standard solid state reaction technique, were studied. Formation of single phase orthorhombic structure of t...Structural and various electrical properties of polycrystalline Ca0.5＋xNd0,5-x（Ti0.5Fe0.5）O3, prepared by standard solid state reaction technique, were studied. Formation of single phase orthorhombic structure of the compositions was confirmed by X-ray diffraction study. The composition dependence of lattice parameters, density and microstructural study show that they vary significantly with Ca content. The dielectric measurements were carried out at room temperature as function of frequency and composition. The experimental results reveal that the dielectric constant （ε′） increases with increasing Ca content. Similar behavior is observed for the dielectric loss （tanδ） and ac conductivity （σac）. In complex impedance analysis it is observed that the real part （Z′） vs imaginary part （Z″） graph exhibits a tendency of formation of a single semicircular arc for each composition of samples. Different parameters were determined by fitting the experimental data in Cole-Cole empirical formula. A dominance of grain boundary resistance （Rgb） is observed. The Rgb decreases with increasing Ca content. The high ε′ observed in present samples are suitable for fabrication of devices.展开更多
Pure Ko.sNao sNbO3(KNN)and KNN doped with Lit(6%mole),Lat(1.66%,5%,6%mole),and Ti+t(10%mole)were prepared by mixture of oxides using high-energy milling and conventional solid-state reaction.The effects of the dopant ...Pure Ko.sNao sNbO3(KNN)and KNN doped with Lit(6%mole),Lat(1.66%,5%,6%mole),and Ti+t(10%mole)were prepared by mixture of oxides using high-energy milling and conventional solid-state reaction.The effects of the dopant on the physical properties of pure KNN have been evaluated based on the structural,ferroelectric,pyroelectric,and dielectric measurements.The XRD measurements show that KNN pure sample contains a mixture of monoclinic and orthorhombic crystalline phases,with a slightly higher concentration of monoclinic phase.In contrast,all doped samples show a higher concentration of the orthorhombic phase,as well as the presence of a secondary phase(K6Nb10.8O3o),also detected by Raman measurements.The samples with a higher concentration of this secondary phase,also present greater dielectric losses and lower values of remnant polarization.The dielectric measurements allowed us to detect temperatures of structural transitions(orthorhombic-tetragonal,O-T)previous to the ferroelectric paraelectric transition(tetragonal-cubic,T-C),and also in this set of samples,a direct correlation was found between the values of remnant polarization and the corresponding pyroelectric signal response.展开更多
基金the partial financial support from the National Natural Science Foundation of China(21935003 and 21805182)National Key Research and Development Plan(2016YFB0901503)+1 种基金Shanghai Pujiang Program(18PJ1403800)the support from the Hundreds of Talents program of Sun Yat-sen University。
文摘Aqueous zinc ion batteries show prospects for next-generation renewable energy storage devices.However,the practical applications have been limited by the issues derived from Zn anode.As one of serious problems,Zn dendrite growth caused from the uncontrollable Zn deposition is unfavorable.Herein,with the aim to regulate Zn deposition,an artificial solid–electrolyte interface is subtly engineered with a perovskite type material,BaTiO3,which can be polarized,and its polarization could be switched under the external electric field.Resulting from the aligned dipole in BaTiO3 layer,zinc ions could move in order during cycling process.Regulated Zn migration at the anode/electrolyte interface contributes to the even Zn stripping/plating and confined Zn dendrite growth.As a result,the reversible Zn plating/stripping processes for over 2000 h have been achieved at 1 mA cm^(−2) with capacity of 1 mAh cm−2.Furthermore,this anode endowing the electric dipoles shows enhanced cycling stability for aqueous Zn-MnO2 batteries.The battery can deliver nearly 100%Coulombic efficiency at 2 Ag^(−1) after 300 cycles.
文摘为克服固体介质内空间电荷和电导分立测量导致实验数据关联性弱的缺陷,基于电声脉冲法原理设计了一套片状试样空间电荷和电导同步测量系统,以获得同片试样在不同电场下的空间电荷和电导动态响应。首先,通过空间电荷测量中电脉冲响应的仿真计算,分析了电脉冲对同步测量时电导的干扰,并采用空间电荷和电导快速分时切换测量的模式解决电脉冲干扰。然后,基于IEC/TS62758-2012空间电荷测量技术校验规范,采用有机玻璃试样对该系统进行了系统验证,以评估空间电荷测量的准确性。最后,采用该系统对低密度聚乙烯(low density polyethylene-LDPE)试样在室温下进行了不同电场时的空间电荷和电导的同步测量,并根据空间电荷时空分布信息计算出位移电流和传导电流分布。结果表明:高(50kV/mm)电场下,半导电/LDPE试样/铝测量结构中LDPE内的位移电流明显低于传导电流,且传导电流的载流子主要源于电极的表面注入,杂质在高场下的解离对传导电流影响不明显。
基金supported by the National Key Research and Development Program of China (2021YFF0500600)National Natural Science Foundation of China (No.U2001220)+1 种基金Shenzhen All-Solid-State Lithium Battery Electrolyte Engineering Research Center (XMHT20200203006)Shenzhen Technical Plan Project (RCJC20200714114436091,JCYJ20220818101003007,and JCYJ20220818101003008)。
基金This work was supported by the National Natural Science Foundation of China(Grant No.50277026)theKey Program of Minis try of Education of China(Grant No.02100)the 973 Project of Ministry of Science and Technology of China(Grant No.2001CB610406).
文摘Pressure wave propagation (PWP) method was utilized to observe the space charges packet-like behavior in sheet samples of low-density polyethylene (LDPE) under the relative low electric field. The experimental results show that space charge packets are always generated at the anode and move across the sample to the cathode regardless of the polarity of DC voltage. This paper discusses the migration of space charge packets at 30–40°C, the possible charge resource of space charge packets carriers and trap level of the space charge.
基金supported by the National Natural Science Foundation of China(Grant Nos.61771104 and 62071106)Jiangxi Innovative Talent Program,and Sichuan Science and Technology Program(Grant No.2021JDTD0026)。
文摘With the help of the first principle calculation,the solid-state reaction experiment was conducted to investigate the alteration in the sintering and the microwave dielectric properties of Mg_(3)B_(2)O_(6)ceramic with many Zn^(2+)substitutions.These properties were characterized using the scanning electron microscopy,network analyzer,X-ray diffraction,Raman spectroscopy,energy-dispersive spectroscopy,and thermomechanical and differential-thermal analyses.The coexistence of Mg_(3)B_(2)O_(6),Mg_(2)B_(2)O_(5)and ZnO ceramics could be observed with increasing Zn^(2+)addition,and the lattice distortion occurred in the Mg_(2)B_(2)O_(5)and Mg_(3)B_(2)O_(6)ceramics due to the substitution of Mg^(2+)with Zn^(2+).The electron density and the bond property of the MgO_(6)octahedron changed,and a quantitative method was used to discuss the variation in sintering,substitution and phase formation properties.The densification window was decreased to 1100℃,and the dielectric properties improved with the formation of a three-phase borate solid solution(dielectric constant=6.73,quality factor=112,000 GHz at 16 GHz(Q=7000),temperature coefficient of resonant frequency=-61.2 ppm℃^(-1),and relative density=97.0%).
基金supported by the National Natural Science Foundation of China(Nos.21971091,21901089 and 22161021)the Natural Science Foundation of Jiangxi Province(No.20212BAB203021)
文摘Accompanied by solid-state structural phase transitions,the switchable molecular dynamics(MD)and order-disorder transformation of(i-PrNHMe2)^(+)cation embedded in a deformable{[Ni(NCS)_(6)]^(4-)}_(∞)supramolecular framework are in-depth investigated by variable-temperature tests of single-crystal X-ray diffraction,dielectric measurement,and MD simulation.Interestingly,it is found that the confined swinging or flipping of the(i-PrNHMe_(2))^(+)cation as a whole is assisted by a synergistic change of its torsion angle.This research provides a helpful insight into the solid-state MD of moderate-sized quasi-spherical molecules/ions that feature a flexible inner core.
基金acknowledge CASR of Bangladesh University of Engineering and Technology(BUET) for financial support for this research
文摘Structural and various electrical properties of polycrystalline Ca0.5＋xNd0,5-x（Ti0.5Fe0.5）O3, prepared by standard solid state reaction technique, were studied. Formation of single phase orthorhombic structure of the compositions was confirmed by X-ray diffraction study. The composition dependence of lattice parameters, density and microstructural study show that they vary significantly with Ca content. The dielectric measurements were carried out at room temperature as function of frequency and composition. The experimental results reveal that the dielectric constant （ε′） increases with increasing Ca content. Similar behavior is observed for the dielectric loss （tanδ） and ac conductivity （σac）. In complex impedance analysis it is observed that the real part （Z′） vs imaginary part （Z″） graph exhibits a tendency of formation of a single semicircular arc for each composition of samples. Different parameters were determined by fitting the experimental data in Cole-Cole empirical formula. A dominance of grain boundary resistance （Rgb） is observed. The Rgb decreases with increasing Ca content. The high ε′ observed in present samples are suitable for fabrication of devices.
基金The authors express their thanks to CONACYT for funding this research through projects CB-240460 and LN-295261,and to LIDTRA for the facilities in the use of experimental infrastructure.
文摘Pure Ko.sNao sNbO3(KNN)and KNN doped with Lit(6%mole),Lat(1.66%,5%,6%mole),and Ti+t(10%mole)were prepared by mixture of oxides using high-energy milling and conventional solid-state reaction.The effects of the dopant on the physical properties of pure KNN have been evaluated based on the structural,ferroelectric,pyroelectric,and dielectric measurements.The XRD measurements show that KNN pure sample contains a mixture of monoclinic and orthorhombic crystalline phases,with a slightly higher concentration of monoclinic phase.In contrast,all doped samples show a higher concentration of the orthorhombic phase,as well as the presence of a secondary phase(K6Nb10.8O3o),also detected by Raman measurements.The samples with a higher concentration of this secondary phase,also present greater dielectric losses and lower values of remnant polarization.The dielectric measurements allowed us to detect temperatures of structural transitions(orthorhombic-tetragonal,O-T)previous to the ferroelectric paraelectric transition(tetragonal-cubic,T-C),and also in this set of samples,a direct correlation was found between the values of remnant polarization and the corresponding pyroelectric signal response.
