An analysis of mechanical, electronic and dynamical properties of antiperovskite Ca<sub>3</sub>BO (B = Pb, Ge, Sn) in cubic phase space group Pm-3m (221) has been studied using first principle density func...An analysis of mechanical, electronic and dynamical properties of antiperovskite Ca<sub>3</sub>BO (B = Pb, Ge, Sn) in cubic phase space group Pm-3m (221) has been studied using first principle density functional theory (DFT). Ground state energy computation was done using the Projector Augmented Wave (PAW) Pseudo Potentials and the Plane Wave (PW) basis set. The Generalized Gradient Approximation (GGA) was used for the exchange correlation. The open source code QUANTUM ESPRESSO (QE) was used in this study in which plane wave basis sets are applied for the expansion of the electronic structure wave function. Thermo_pw as a post-processing code was used for the computation of mechanical properties including bulk modulus and elastic constants with their derivatives. The lattice parameters are here calculated to be 4.87 Å, 4.86 Å and 4.84 Å for Ca<sub>3</sub>BO (B = Pb, Ge, Sn) respectively which compares well with other works. This also shows that the three crystals are similar in size and in most of their properties. In addition to this, projected density of states and band structure are also computed both showing that these materials are of semi-metallic nature and are stable in cubic phase. Phonon modes at gamma are also reported.展开更多
Glassy electrolytes could be a potential candidate for all-solid-state batteries that are considered new-generation energy storage devices. As glasses are one of the potential fast ion-conducting electrolytes, progres...Glassy electrolytes could be a potential candidate for all-solid-state batteries that are considered new-generation energy storage devices. As glasses are one of the potential fast ion-conducting electrolytes, progressive advances in glassy electrolytes have been undergoing to get commercial attention. However, the challenges offered by ionic conductivity at room temperature (10<sup>−5</sup> - 10<sup>−3</sup> S∙cm<sup>−1</sup>) in comparison to those of organic liquid electrolytes (10<sup>−2</sup> S∙cm<sup>−1</sup>) hindered the applicability of such electrolytes. To enhance the research development on ionic conductivity, the overall picture of the ionic conductivity of glassy electrolytes is reviewed in this article with a focus on alkali oxide and sulfide glasses. We portray here the techniques applied for alkali ion conductivity enhancement, such as methods of glass preparation, host optimization, doping, and salt addition for enhancing alkali ionic conductivity in the glasses.展开更多
The negative thermal expansion （NTE） properties of the antiperovskite manganese nitrides with micron-scale, submicron-scale and nanometer-scale microstructures, respectively, were investigated using the Mn3Cu0.5Ge0....The negative thermal expansion （NTE） properties of the antiperovskite manganese nitrides with micron-scale, submicron-scale and nanometer-scale microstructures, respectively, were investigated using the Mn3Cu0.5Ge0.5N composition as an example. It was discovered that the NTE start temperature, NTE operation temperature range and coefficient of NTE change obviously in a wide range with decreasing the grain size level of the microstructure. The mechanisms for the broadening of the NTE operation temperature range and the decrease in the absolute value of NTE coefficient were proposed based on the grain-size-dependence of the frustrated magnetic interactions and magnetic ordering. The present study indicates that the NTE properties of the antiperovskite manganese nitrides can be tailored by the control of the microstructure scale.展开更多
Our recent research on the Mn-based antiperovskite functional materials AXMn3 （A： metal or semiconducting elements; X： C or N） is outlined. Antiperovskite carbides （e.g., AlCMn3） show large magnetocaloric effect...Our recent research on the Mn-based antiperovskite functional materials AXMn3 （A： metal or semiconducting elements; X： C or N） is outlined. Antiperovskite carbides （e.g., AlCMn3） show large magnetocaloric effect comparable to those of typical magnetic refrigerant materials. Enhanced giant magnetoresistance up to 70% at 50 kOe （1 Oe=79.5775 A.m-1） over a wide temperature span was obtained in Ga1-xZnxCMn3 and GaCMn3 xNix. In Cu0.3Sn0.5NMn3.2, negative thermal expansion （NTE） was achieved in a wide temperature region covering room temperature （α = -6.8 ppm/K, 150 K-40 K）. Neutron pair distribution function analysis suggests the Cu/Sn-Mn bond fluctuation is the driving force for the NTE in Cu1- xSnxNMn3. In CuN1- xCxMn3 and CuNMn3 yCoy, the temperature coefficient of resistivity （TCR） decreases monotonically from positive to negative as Co or C content increases. TCR is extremely low when the composition approaches the critical points. For example, TCR is - 1.29 ppm/K between 240 K and 320 K in CuN0.95C0 05Mn3, which is one twentieth of that in the typical low-TCR materials （- 25 ppm/K）. By studying the critical scaling behavior and X deficiency effect, some clues of localized-electron magnetism have been found against the background of electronic itinerant magnetism.展开更多
The development of all-solid-state lithium batteries(ASSLBs)depends on exploiting solid-state electrolytes(SSEs)with high ionic conductivity and electrochemical stability.Fluorination is generally considered to be an ...The development of all-solid-state lithium batteries(ASSLBs)depends on exploiting solid-state electrolytes(SSEs)with high ionic conductivity and electrochemical stability.Fluorination is generally considered to be an effective strategy to improve the ionic conductivity and electrochemical stability of inorganic SSEs.Here,we report the partial fluorination of the chlo rine sites in an antiperovskite,by which the orthorhombic Li_(2)OHCl was transformed into cubic Li_(2)OHCl_(0.9)F_(0.1),resulting in a fourfold increase in ionic conductivity at 30℃.The ab initio molecular dynamics simulations suggest that both the crystal symmetry and the anions electronegativity influence the diffusion of Li+in the antiperovskite structure.Besides,from the perspective of experiments and calculations,it is confirmed that fluorination is a feasible method to improve the electrochemical stability of antiperovskite SSEs.The LiFePO_(4)|Li cell based on Li_(2)OHCl_(0.9)F_(0.1) is also assembled and exhibits stable cycle performance,which indicates that fluorination of antiperovskite SSEs is an effective way to produce high-performance SSEs for practical application of ASSLBs.展开更多
反钙钛矿作为一种有潜力的新型非贵金属电催化材料,组分上不同过渡金属的填充使得反钙钛矿在析氧反应和氧还原反应表现突出,有望成为一种高效的双功能氧电催化剂。首次通过静电纺丝法结合高温煅烧法制备出碳纤维负载的立方相反钙钛矿电...反钙钛矿作为一种有潜力的新型非贵金属电催化材料,组分上不同过渡金属的填充使得反钙钛矿在析氧反应和氧还原反应表现突出,有望成为一种高效的双功能氧电催化剂。首次通过静电纺丝法结合高温煅烧法制备出碳纤维负载的立方相反钙钛矿电催化剂Zn CNi_(3)/CNFs,该催化剂结合了反钙钛矿与碳基材料导电性高、催化活性好的优点。对Zn CNi_(3)/CNFs进行电催化性能的研究测试表明,在碱性条件下其析氧反应表现出优异的催化活性,在10 m A/cm^(2)的电流密度时,Zn CNi_(3)/CNFs过电位仅为340 m V。在氧还原反应测试中,其半波电位为0.64 V (vs.RHE),极限电流密度可达-3.49 m A/cm^(2)。该研究为设计合成纯相反钙钛矿碳化物,并实现双功能反钙钛矿氧电催化剂提供基础。展开更多
Hydrostatic pressure provides an efficient way to tune and optimize the properties of solid materials without chang-ing their composition.In this work,we investigate the electronic,optical,and mechanical properties of...Hydrostatic pressure provides an efficient way to tune and optimize the properties of solid materials without chang-ing their composition.In this work,we investigate the electronic,optical,and mechanical properties of antiperovskite X_(3)NP(X^(2+)=Ca,Mg)upon compression by first-principles calculations.Our results reveal that the system is anisotropic,and the lat-tice constant a of X_(3)NP exhibits the fastest rate of decrease upon compression among the three directions,which is different from the typical Pnma phase of halide and chalcogenide perovskites.Meanwhile,Ca_(3)NP has higher compressibility than Mg_(3)NP due to its small bulk modulus.The electronic and optical properties of Mg_(3)NP show small fluctuations upon compression,but those of Ca_(3)NP are more sensitive to pressure due to its higher compressibility and lower unoccupied 3d orbital energy.For example,the band gap,lattice dielectric constant,and exciton binding energy of Ca_(3)NP decrease rapidly as the pressure increases.In addition,the increase in pressure significantly improves the optical absorption and theoretical conversion effi-ciency of Ca_(3)NP.Finally,the mechanical properties of X_(3)NP are also increased upon compression due to the reduction in bond length,while inducing a brittle-to-ductile transition.Our research provides theoretical guidance and insights for future experi-mental tuning of the physical properties of antiperovskite semiconductors by pressure.展开更多
Solid-state electrolytes(SSEs)play the most important role in the development of cutting-edge all-solid-state bat-teries(ASSBs).The lithium(sodium)-rich antiperovskite solid conductors have been considered as the prom...Solid-state electrolytes(SSEs)play the most important role in the development of cutting-edge all-solid-state bat-teries(ASSBs).The lithium(sodium)-rich antiperovskite solid conductors have been considered as the promising SSEs due to the structural tolerance for lattice manipulation and the potential to improve ionic conductivity.In particular,lithium(sodium)-rich antiperovskite SSEs are mainly composed of light elements(e.g.,Li,O,H),which are suitable for studying the structure and ionic transport mechanism through neutron diffraction techniques.This present review summarizes the progress of neutron diffraction in analyzing the structure and revealing the ionic transport mechanisms of antiperovskite SSEs.The structure-function relationships involved in ionic transport pathways,defect chemistry,anion disorder and lattice dynamics are introduced respectively.In addition,the possible future directions for the application of neutron diffraction in antiperovskite SSEs are suggested.展开更多
Li7P3S11solid electrolytes with high lithium-ion conductivity are promising candidates for use in all-solidstate lithium batteries.However,this electrolyte’s poor interfacial compatibility with lithium electrodes cau...Li7P3S11solid electrolytes with high lithium-ion conductivity are promising candidates for use in all-solidstate lithium batteries.However,this electrolyte’s poor interfacial compatibility with lithium electrodes causes unstable cyclability.In this study,in order to address this problem,(100-x)Li7P3S11-xLi2OHBr(x=0,2,5,10,20,30,40,and 50)electrolytes are prepared by a high energy ball-milling technique and heat-treatment process.The resulting(100-x)Li7P3S11-xLi2OHBr(x=2,5,10,20,30,40,and 50)electrolytes provide improved electrochemical performance with good cycling stability and a wide electrochemical window of up to 10 V(vs.Li/Li+).Moreover,these electrolytes have high ionic conductivity of 10-4–10-5S/cm at room temperature.Particularly,the 90Li7P3S11-10Li2OHBr electrolyte displays the highest conductivity of 4.4×10-4S/cm at room temperature as well as improved cyclability.Moreover,90Li7P3S11-10Li2OHBr shows decreased interfacial resistance between the solid electrolyte and cathode electrode,which was revealed by Electrochemical Impedance Spectroscopy(EIS)analysis.The initial discharge capacity of 90Li7P3S11-10Li2OHBr was found to be 135 m Ah/g when used in a In|solid electrolyte|Li(Ni0.6Co0.2Mn0.2)O2 all-solid-state lithium battery(ASSLB).Thus,we can conclude the addition of Li2OHBr into the Li7P3S11results in enhanced electrochemical properties.展开更多
Anti-perovskites X3BA,as the electrically inverted derivatives of perovskites ABX3,have attracted tremendous attention for their good performances in multiple disciplines,especially in energy storage batteries.The Li/...Anti-perovskites X3BA,as the electrically inverted derivatives of perovskites ABX3,have attracted tremendous attention for their good performances in multiple disciplines,especially in energy storage batteries.The Li/Na-rich antiperovskite(LiRAP/NaRAP)solid-state electrolytes(SSEs)typically show high ionic conductivities and high chemical/electrochemical stability toward the Li-metal anode,illustrating their great potential for applications in the Limetal batteries(LMBs)using nonaqueous liquid electrolyte or all-solid-state electrolyte.The antiperovskites have been studied as artificial solid electrolyte interphase for Li-metal anode protection,film SSEs for thin-film batteries,and low melting temperature solid electrolyte enabling melt-infiltration for the manufacture of all-solid-state lithium batteries.Transition metal-doped LiRAPs as cathodes have demonstrated a high discharge specific capacity and good rate capability in the Li-ion batteries(LIBs).Additionally,the underlying scientific principles in antiperovskites with flexible structural features have also been extensively studied.In this review,we comprehensively summarize the development,structural design,ionic conductivity and ion transportation mechanism,chemical/electrochemical stability,and applications of some antiperovskite materials in energy storage batteries.The perspective for enhancing the performance of the antiperovskites is also provided as a guide for future development and applications in energy storage.展开更多
Very recently, a new Ni-based antiperovskite nitride superconductor CuNNi3 has been successfully synthesized. We investigate the electronic structures, phonon dispersions, and electron–phonon interactions of CuNNi3 a...Very recently, a new Ni-based antiperovskite nitride superconductor CuNNi3 has been successfully synthesized. We investigate the electronic structures, phonon dispersions, and electron–phonon interactions of CuNNi3 and the isostructual ZnNNi3 by first-principles approach. By analyzing the Eliashberg function we obtain the superconducting transition temperature Tc 3.16 K(3.53 K), which is in good agreement with corresponding experimental Tc 3.2 K(3 K) for Cu NNi3(ZnNNi3). They can be verified as conventional phonon-mediated superconductors.展开更多
The low-temperature heat capacities are studied for antiperovskite compounds AX M_3（A = Al, Ga, Cu, Ag, Sn, X = C,N, M = Mn, Fe, Co）. A large peak in（C- γ T）/T^3 versus T is observed for each of a total of 18 com...The low-temperature heat capacities are studied for antiperovskite compounds AX M_3（A = Al, Ga, Cu, Ag, Sn, X = C,N, M = Mn, Fe, Co）. A large peak in（C- γ T）/T^3 versus T is observed for each of a total of 18 compounds investigated,indicating an existence of low-energy phonon mode unexpected by Debye T^3 law. Such a peak is insensitive to the external magnetic field up to 80 k Oe（1 Oe = 79.5775 A·m-1）. For compounds with smaller lattice constant, the peak shifts towards higher temperatures with a reduction of peak height. This abnormal peak in（C- γ T）/T^3 versus T of antiperovskite compound may result from the strongly dispersive acoustic branch due to the heavier A atoms and the optical-like mode from the dynamic rotation of X M_6 octahedron. Such a low-energy phonon mode may not contribute negatively to the normal thermal expansion in AX M_3 compounds, while it is usually concomitant with negative thermal expansion in open-structure material（e.g., ZrW_2O_8, Sc F_3）.展开更多
Two series of Cdl-xInxNNi3 （0 〈 x 〈 0.2） and Cd1_yCuyNNi3 （0 〈 y 〈 0.2） samples were prepared from CdO, In203, CuO, and nickel powders under NH3 atmosphere at 773 K. The structural and physical properties were...Two series of Cdl-xInxNNi3 （0 〈 x 〈 0.2） and Cd1_yCuyNNi3 （0 〈 y 〈 0.2） samples were prepared from CdO, In203, CuO, and nickel powders under NH3 atmosphere at 773 K. The structural and physical properties were investigated by means of X-ray powder diffraction temperature-dependent resistivity and magnetic measurements. X-ray powder diffraction results showed that the Cd1-xInxNNi3 and Cd1_yCuyNNi3 compounds have a typical antiperovskite structure, and the CdNNi3, Cd0.9In0.1NNi3, and Cd0.9Cu0.1NNia compounds show metallic temperature-dependent resistivity and exhibit a Fermi liquid behavior at low temperature. In contrast to the paramagnetism previously reported, the CdNNi3 sample exhibits very soft and weak ferromagnetism, and no superconductivity was found in the Cd1-xInxNNi3 and Cdl-yCuyNNi3 samples down to 2 K. Each sample exhibited very soft and weak ferromagnetism, and the temperature dependence of the magnetization of the Cd1-xInxNNi3 and Cd1_yCuyNNi3 samples can be well fitted to the combination of a Bloch term and a Curie-Weiss term.展开更多
We demonstrate the first successful attempt to partially substitute Cu into the Mn_(3)AgN-antiperovskite system to form Mn_(3)Ag_((1-x))Cu_((x))N thin films with an ultra-low temperature coefficient of resistance(TCR)...We demonstrate the first successful attempt to partially substitute Cu into the Mn_(3)AgN-antiperovskite system to form Mn_(3)Ag_((1-x))Cu_((x))N thin films with an ultra-low temperature coefficient of resistance(TCR)for fabrication of ultra-precise passive components.Films were grown by reactive magnetron sputtering on alumina and glass substrates and were found to be amorphous in nature with highly negative TCR of-233 to-351 ppm/℃in their as-grown state.Increasing Cu alloying from x=0 to 1,resulted in increased sheet resistance,a negative shift of TCR and a change of grain morphology from spherical to elongated.Post-deposition heat treatment at 300-375℃,resulted in a positive shift of TCR and an ultra-low TCR of-4.66 ppm/℃for films with x=0.6.The heat treatment induces grain growth,surface roughness and the formation of a manganese oxide upper surface layer up until temperatures of 350℃,after which surface oxidation begins to dominate.The growth rate of the surface layer is controlled by the Cu concentration and heat treatment temperature,which both play a central role in the development of these novel ultralow TCR Mn_(3)Ag_((1-x))Cu_((x))N thin film structures.展开更多
Using spark plasma sintering （SPS）, Mn3Cu0.6Ge0.4N crystallites have been fabricated with different crystallite sizes, and their magnetic properties and thermal behaviors were systemically investigated. With decreas...Using spark plasma sintering （SPS）, Mn3Cu0.6Ge0.4N crystallites have been fabricated with different crystallite sizes, and their magnetic properties and thermal behaviors were systemically investigated. With decreasing crystallite size, the magnetic transition becomes increasingly slow, accompanied by broadening of the negative thermal expansion （NTE） operation-temperature window. The NTE operation-temperature window for the 12-nm crystallite sample reaches at 140 K, which is about 75% larger than that of the 74-nm crystallite sample. The magnetic properties and NTE operation-temperature window can be tuned by varying the crystallite size. This discovery will promote an even wider range of practical applications in precision devices.展开更多
Searching for effective hydrogen evolution reaction(HER)electrocatalysts is crucial for water splitting.Transition metal nitrides(TMNs)are very attractive potential candidates since of high electrical conductivity,rob...Searching for effective hydrogen evolution reaction(HER)electrocatalysts is crucial for water splitting.Transition metal nitrides(TMNs)are very attractive potential candidates since of high electrical conductivity,robust stability,element rich and high activity.Antiperovskite metal nitrides provide chemical flexibility since two different types of transition metal elements are contained,allowing partial substitution both for A-and M-sites.Herein,we report a novel antiperovskite metal nitride Ag_(x)Ni_(1-x)NNi_(3)(0≤x≤0.80)thin film used as highly effective HER electrocatalysts.Pure phase antiperovskite nitride can be successfully obtained for Ag_(x)Ni_(1-x)NNi_(3)with x less than 0.80.The Ag_(0.76)Ni_(0.24)NNi_(3) towards HER shows an overpotential of 122 mV at 10 mA cm^(-2)in alkaline media.Furthermore,considering the role of Ag for adsorbing hydroxyl groups,chemical engineering has been carried out for designing metal/antiperovskite nitride Ag/Ag_(x)Ni_(1-x)NNi_(3)composite electrocatalysts.The 0.18 Ag/Ag_(0.80)Ni_(0.20)NNi_(3)electrocatalyst shows a mere 13 and 81 mV of overpotential to reach 1 and 10 mA cm^(-2),respectively,showing high durability in alkaline media.These results will provide a novel type of HER catalysts based on antiperovskite metal nitrides and a strategic design for metal/antiperovskite metal nitride composite electrocatalysts for HER in alkaline media.展开更多
文摘An analysis of mechanical, electronic and dynamical properties of antiperovskite Ca<sub>3</sub>BO (B = Pb, Ge, Sn) in cubic phase space group Pm-3m (221) has been studied using first principle density functional theory (DFT). Ground state energy computation was done using the Projector Augmented Wave (PAW) Pseudo Potentials and the Plane Wave (PW) basis set. The Generalized Gradient Approximation (GGA) was used for the exchange correlation. The open source code QUANTUM ESPRESSO (QE) was used in this study in which plane wave basis sets are applied for the expansion of the electronic structure wave function. Thermo_pw as a post-processing code was used for the computation of mechanical properties including bulk modulus and elastic constants with their derivatives. The lattice parameters are here calculated to be 4.87 Å, 4.86 Å and 4.84 Å for Ca<sub>3</sub>BO (B = Pb, Ge, Sn) respectively which compares well with other works. This also shows that the three crystals are similar in size and in most of their properties. In addition to this, projected density of states and band structure are also computed both showing that these materials are of semi-metallic nature and are stable in cubic phase. Phonon modes at gamma are also reported.
文摘Glassy electrolytes could be a potential candidate for all-solid-state batteries that are considered new-generation energy storage devices. As glasses are one of the potential fast ion-conducting electrolytes, progressive advances in glassy electrolytes have been undergoing to get commercial attention. However, the challenges offered by ionic conductivity at room temperature (10<sup>−5</sup> - 10<sup>−3</sup> S∙cm<sup>−1</sup>) in comparison to those of organic liquid electrolytes (10<sup>−2</sup> S∙cm<sup>−1</sup>) hindered the applicability of such electrolytes. To enhance the research development on ionic conductivity, the overall picture of the ionic conductivity of glassy electrolytes is reviewed in this article with a focus on alkali oxide and sulfide glasses. We portray here the techniques applied for alkali ion conductivity enhancement, such as methods of glass preparation, host optimization, doping, and salt addition for enhancing alkali ionic conductivity in the glasses.
基金supported by the National Natural Science Foundation of China(No.51174009)the Beijing Natural Science Foundation(No.2112006)the Chinese National Programs for Fundamental Research and Development(No.2011CB612207)
文摘The negative thermal expansion （NTE） properties of the antiperovskite manganese nitrides with micron-scale, submicron-scale and nanometer-scale microstructures, respectively, were investigated using the Mn3Cu0.5Ge0.5N composition as an example. It was discovered that the NTE start temperature, NTE operation temperature range and coefficient of NTE change obviously in a wide range with decreasing the grain size level of the microstructure. The mechanisms for the broadening of the NTE operation temperature range and the decrease in the absolute value of NTE coefficient were proposed based on the grain-size-dependence of the frustrated magnetic interactions and magnetic ordering. The present study indicates that the NTE properties of the antiperovskite manganese nitrides can be tailored by the control of the microstructure scale.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11174295,51001094,91222109,51171177,and 50701042)the National Key Basic Research of China (Grant No. 2011CBA00111)
文摘Our recent research on the Mn-based antiperovskite functional materials AXMn3 （A： metal or semiconducting elements; X： C or N） is outlined. Antiperovskite carbides （e.g., AlCMn3） show large magnetocaloric effect comparable to those of typical magnetic refrigerant materials. Enhanced giant magnetoresistance up to 70% at 50 kOe （1 Oe=79.5775 A.m-1） over a wide temperature span was obtained in Ga1-xZnxCMn3 and GaCMn3 xNix. In Cu0.3Sn0.5NMn3.2, negative thermal expansion （NTE） was achieved in a wide temperature region covering room temperature （α = -6.8 ppm/K, 150 K-40 K）. Neutron pair distribution function analysis suggests the Cu/Sn-Mn bond fluctuation is the driving force for the NTE in Cu1- xSnxNMn3. In CuN1- xCxMn3 and CuNMn3 yCoy, the temperature coefficient of resistivity （TCR） decreases monotonically from positive to negative as Co or C content increases. TCR is extremely low when the composition approaches the critical points. For example, TCR is - 1.29 ppm/K between 240 K and 320 K in CuN0.95C0 05Mn3, which is one twentieth of that in the typical low-TCR materials （- 25 ppm/K）. By studying the critical scaling behavior and X deficiency effect, some clues of localized-electron magnetism have been found against the background of electronic itinerant magnetism.
基金supported by the National Key Research and Development Program of China(2020YFA0210701)the National Natural Science Foundation of China(22005134,12275119,U22A20439)+4 种基金the Shenzhen Science and Technology Program(RCBS20210609103647030)the Guangdong Basic and Applied Basic Research Foundation(2021A1515012403)the Shenzhen Science and Technology Program(KQTD20200820113047086)the Guangdong-Hong Kong-Macao Joint Laboratory for PhotonicThermal-Electrical Energy Materials and Devices(2019B121205001)the open research fund of Songshan Lake Materials Laboratory(2022SLABFK04)。
文摘The development of all-solid-state lithium batteries(ASSLBs)depends on exploiting solid-state electrolytes(SSEs)with high ionic conductivity and electrochemical stability.Fluorination is generally considered to be an effective strategy to improve the ionic conductivity and electrochemical stability of inorganic SSEs.Here,we report the partial fluorination of the chlo rine sites in an antiperovskite,by which the orthorhombic Li_(2)OHCl was transformed into cubic Li_(2)OHCl_(0.9)F_(0.1),resulting in a fourfold increase in ionic conductivity at 30℃.The ab initio molecular dynamics simulations suggest that both the crystal symmetry and the anions electronegativity influence the diffusion of Li+in the antiperovskite structure.Besides,from the perspective of experiments and calculations,it is confirmed that fluorination is a feasible method to improve the electrochemical stability of antiperovskite SSEs.The LiFePO_(4)|Li cell based on Li_(2)OHCl_(0.9)F_(0.1) is also assembled and exhibits stable cycle performance,which indicates that fluorination of antiperovskite SSEs is an effective way to produce high-performance SSEs for practical application of ASSLBs.
文摘反钙钛矿作为一种有潜力的新型非贵金属电催化材料,组分上不同过渡金属的填充使得反钙钛矿在析氧反应和氧还原反应表现突出,有望成为一种高效的双功能氧电催化剂。首次通过静电纺丝法结合高温煅烧法制备出碳纤维负载的立方相反钙钛矿电催化剂Zn CNi_(3)/CNFs,该催化剂结合了反钙钛矿与碳基材料导电性高、催化活性好的优点。对Zn CNi_(3)/CNFs进行电催化性能的研究测试表明,在碱性条件下其析氧反应表现出优异的催化活性,在10 m A/cm^(2)的电流密度时,Zn CNi_(3)/CNFs过电位仅为340 m V。在氧还原反应测试中,其半波电位为0.64 V (vs.RHE),极限电流密度可达-3.49 m A/cm^(2)。该研究为设计合成纯相反钙钛矿碳化物,并实现双功能反钙钛矿氧电催化剂提供基础。
基金supported by the Science and Technology Research Program of Chongqing Municipal Education Commission (Grant No. KJQN202100626)the Science and Technology Research Program of Chongqing Municipal Education Commission (Grant No. KJQN202200619)+3 种基金supported by Beijing Institute of Technology Research Fund Program for Young Scholars (Grant No. XSQD-202222008)the support from the National Natural Science Foundation of China (Grant No. 12204081)the Natural Science Foundation of Chongqing (Grant No. 2022NSCQ-MSX2540)supported by TianHe Qingsuo Project-spec ial fund project
文摘Hydrostatic pressure provides an efficient way to tune and optimize the properties of solid materials without chang-ing their composition.In this work,we investigate the electronic,optical,and mechanical properties of antiperovskite X_(3)NP(X^(2+)=Ca,Mg)upon compression by first-principles calculations.Our results reveal that the system is anisotropic,and the lat-tice constant a of X_(3)NP exhibits the fastest rate of decrease upon compression among the three directions,which is different from the typical Pnma phase of halide and chalcogenide perovskites.Meanwhile,Ca_(3)NP has higher compressibility than Mg_(3)NP due to its small bulk modulus.The electronic and optical properties of Mg_(3)NP show small fluctuations upon compression,but those of Ca_(3)NP are more sensitive to pressure due to its higher compressibility and lower unoccupied 3d orbital energy.For example,the band gap,lattice dielectric constant,and exciton binding energy of Ca_(3)NP decrease rapidly as the pressure increases.In addition,the increase in pressure significantly improves the optical absorption and theoretical conversion effi-ciency of Ca_(3)NP.Finally,the mechanical properties of X_(3)NP are also increased upon compression due to the reduction in bond length,while inducing a brittle-to-ductile transition.Our research provides theoretical guidance and insights for future experi-mental tuning of the physical properties of antiperovskite semiconductors by pressure.
基金supported by the open research fund of Songshan Lake Materials Laboratory(2022SLABFK04)the National Natural Science Foundation of China(12275119,52227802,U22A20439)+3 种基金Shenzhen Science and Technology Program(KQTD20200820113047086)Shenzhen Foundation Research Fund granted by the Shenzhen Science and Technology Innovation Committee(JCYJ20220530112812028)Guangdong Grants(2021ZT09C064)Major Science and Technology Infrastructure Project of Material Genome Big science Facilities Platform supported by the Municipal Development and Reform Commission of Shenzhen.
文摘Solid-state electrolytes(SSEs)play the most important role in the development of cutting-edge all-solid-state bat-teries(ASSBs).The lithium(sodium)-rich antiperovskite solid conductors have been considered as the promising SSEs due to the structural tolerance for lattice manipulation and the potential to improve ionic conductivity.In particular,lithium(sodium)-rich antiperovskite SSEs are mainly composed of light elements(e.g.,Li,O,H),which are suitable for studying the structure and ionic transport mechanism through neutron diffraction techniques.This present review summarizes the progress of neutron diffraction in analyzing the structure and revealing the ionic transport mechanisms of antiperovskite SSEs.The structure-function relationships involved in ionic transport pathways,defect chemistry,anion disorder and lattice dynamics are introduced respectively.In addition,the possible future directions for the application of neutron diffraction in antiperovskite SSEs are suggested.
基金supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2018R1D1A3B070050296)。
文摘Li7P3S11solid electrolytes with high lithium-ion conductivity are promising candidates for use in all-solidstate lithium batteries.However,this electrolyte’s poor interfacial compatibility with lithium electrodes causes unstable cyclability.In this study,in order to address this problem,(100-x)Li7P3S11-xLi2OHBr(x=0,2,5,10,20,30,40,and 50)electrolytes are prepared by a high energy ball-milling technique and heat-treatment process.The resulting(100-x)Li7P3S11-xLi2OHBr(x=2,5,10,20,30,40,and 50)electrolytes provide improved electrochemical performance with good cycling stability and a wide electrochemical window of up to 10 V(vs.Li/Li+).Moreover,these electrolytes have high ionic conductivity of 10-4–10-5S/cm at room temperature.Particularly,the 90Li7P3S11-10Li2OHBr electrolyte displays the highest conductivity of 4.4×10-4S/cm at room temperature as well as improved cyclability.Moreover,90Li7P3S11-10Li2OHBr shows decreased interfacial resistance between the solid electrolyte and cathode electrode,which was revealed by Electrochemical Impedance Spectroscopy(EIS)analysis.The initial discharge capacity of 90Li7P3S11-10Li2OHBr was found to be 135 m Ah/g when used in a In|solid electrolyte|Li(Ni0.6Co0.2Mn0.2)O2 all-solid-state lithium battery(ASSLB).Thus,we can conclude the addition of Li2OHBr into the Li7P3S11results in enhanced electrochemical properties.
基金Key Program of the National Natural Science Foundationof China,Grant/Award Number:51732005Guangdong Basic and Applied Basic Research Foundation,Grant/Award Number:2021A1515011784+1 种基金Key Laboratory of Energy Conversion and Storage Technologies(Southern University of Science and Technology),Ministry of EducationShenzhen Science and Technology Program,Grant/Award Number:KQTD20200820113047086。
文摘Anti-perovskites X3BA,as the electrically inverted derivatives of perovskites ABX3,have attracted tremendous attention for their good performances in multiple disciplines,especially in energy storage batteries.The Li/Na-rich antiperovskite(LiRAP/NaRAP)solid-state electrolytes(SSEs)typically show high ionic conductivities and high chemical/electrochemical stability toward the Li-metal anode,illustrating their great potential for applications in the Limetal batteries(LMBs)using nonaqueous liquid electrolyte or all-solid-state electrolyte.The antiperovskites have been studied as artificial solid electrolyte interphase for Li-metal anode protection,film SSEs for thin-film batteries,and low melting temperature solid electrolyte enabling melt-infiltration for the manufacture of all-solid-state lithium batteries.Transition metal-doped LiRAPs as cathodes have demonstrated a high discharge specific capacity and good rate capability in the Li-ion batteries(LIBs).Additionally,the underlying scientific principles in antiperovskites with flexible structural features have also been extensively studied.In this review,we comprehensively summarize the development,structural design,ionic conductivity and ion transportation mechanism,chemical/electrochemical stability,and applications of some antiperovskite materials in energy storage batteries.The perspective for enhancing the performance of the antiperovskites is also provided as a guide for future development and applications in energy storage.
基金supported by the Scientific Research Fund of Guilin University of Aerospace Technology,China(Grant No.YJ1410)
文摘Very recently, a new Ni-based antiperovskite nitride superconductor CuNNi3 has been successfully synthesized. We investigate the electronic structures, phonon dispersions, and electron–phonon interactions of CuNNi3 and the isostructual ZnNNi3 by first-principles approach. By analyzing the Eliashberg function we obtain the superconducting transition temperature Tc 3.16 K(3.53 K), which is in good agreement with corresponding experimental Tc 3.2 K(3 K) for Cu NNi3(ZnNNi3). They can be verified as conventional phonon-mediated superconductors.
基金Project supported by the National Key Basic Research Program of China(Grant Nos.2011CBA00111)the National Natural Science Foundation of China(Grant Nos.51322105,U1632158,51301165,and 51301167)
文摘The low-temperature heat capacities are studied for antiperovskite compounds AX M_3（A = Al, Ga, Cu, Ag, Sn, X = C,N, M = Mn, Fe, Co）. A large peak in（C- γ T）/T^3 versus T is observed for each of a total of 18 compounds investigated,indicating an existence of low-energy phonon mode unexpected by Debye T^3 law. Such a peak is insensitive to the external magnetic field up to 80 k Oe（1 Oe = 79.5775 A·m-1）. For compounds with smaller lattice constant, the peak shifts towards higher temperatures with a reduction of peak height. This abnormal peak in（C- γ T）/T^3 versus T of antiperovskite compound may result from the strongly dispersive acoustic branch due to the heavier A atoms and the optical-like mode from the dynamic rotation of X M_6 octahedron. Such a low-energy phonon mode may not contribute negatively to the normal thermal expansion in AX M_3 compounds, while it is usually concomitant with negative thermal expansion in open-structure material（e.g., ZrW_2O_8, Sc F_3）.
基金Project supported by the National Natural Science Foundation of China （Grant No. 20871119）, the National Basic Research Program of China （973 Program） （Grant Nos. 2011CBA00112 and 2011CB808202）, and the Natural Science Foundation of Luzhou Medical College.
文摘Two series of Cdl-xInxNNi3 （0 〈 x 〈 0.2） and Cd1_yCuyNNi3 （0 〈 y 〈 0.2） samples were prepared from CdO, In203, CuO, and nickel powders under NH3 atmosphere at 773 K. The structural and physical properties were investigated by means of X-ray powder diffraction temperature-dependent resistivity and magnetic measurements. X-ray powder diffraction results showed that the Cd1-xInxNNi3 and Cd1_yCuyNNi3 compounds have a typical antiperovskite structure, and the CdNNi3, Cd0.9In0.1NNi3, and Cd0.9Cu0.1NNia compounds show metallic temperature-dependent resistivity and exhibit a Fermi liquid behavior at low temperature. In contrast to the paramagnetism previously reported, the CdNNi3 sample exhibits very soft and weak ferromagnetism, and no superconductivity was found in the Cd1-xInxNNi3 and Cdl-yCuyNNi3 samples down to 2 K. Each sample exhibited very soft and weak ferromagnetism, and the temperature dependence of the magnetization of the Cd1-xInxNNi3 and Cd1_yCuyNNi3 samples can be well fitted to the combination of a Bloch term and a Curie-Weiss term.
文摘We demonstrate the first successful attempt to partially substitute Cu into the Mn_(3)AgN-antiperovskite system to form Mn_(3)Ag_((1-x))Cu_((x))N thin films with an ultra-low temperature coefficient of resistance(TCR)for fabrication of ultra-precise passive components.Films were grown by reactive magnetron sputtering on alumina and glass substrates and were found to be amorphous in nature with highly negative TCR of-233 to-351 ppm/℃in their as-grown state.Increasing Cu alloying from x=0 to 1,resulted in increased sheet resistance,a negative shift of TCR and a change of grain morphology from spherical to elongated.Post-deposition heat treatment at 300-375℃,resulted in a positive shift of TCR and an ultra-low TCR of-4.66 ppm/℃for films with x=0.6.The heat treatment induces grain growth,surface roughness and the formation of a manganese oxide upper surface layer up until temperatures of 350℃,after which surface oxidation begins to dominate.The growth rate of the surface layer is controlled by the Cu concentration and heat treatment temperature,which both play a central role in the development of these novel ultralow TCR Mn_(3)Ag_((1-x))Cu_((x))N thin film structures.
基金This work was supported by the National Natural Science Foundation of China （Nos. 51232004, 51377156, and 51401224）, the National Magnetic Confinement Fusion Science Program （No. 2015GB121001）, the fund of the State Key Laboratory of Technologies in Space Cryogenic Propellants （No. SKLTSCP1204）, and the Special Foundation of the Director Technical Institute of Physics and Chemistry, CAS.
文摘Using spark plasma sintering （SPS）, Mn3Cu0.6Ge0.4N crystallites have been fabricated with different crystallite sizes, and their magnetic properties and thermal behaviors were systemically investigated. With decreasing crystallite size, the magnetic transition becomes increasingly slow, accompanied by broadening of the negative thermal expansion （NTE） operation-temperature window. The NTE operation-temperature window for the 12-nm crystallite sample reaches at 140 K, which is about 75% larger than that of the 74-nm crystallite sample. The magnetic properties and NTE operation-temperature window can be tuned by varying the crystallite size. This discovery will promote an even wider range of practical applications in precision devices.
基金financially supported by the National Key R&D Program of China(Nos.2016YFA0401801 and 2014CB931704)the Natural Science Foundation of Anhui Province(No.1608085QE107)+1 种基金the Key Research Program of Frontier Sciences,CAS(No.QYZDB-SSW-SLH015)supported by the Youth Innovation Promotion Association of CAS(No.2014283)。
文摘Searching for effective hydrogen evolution reaction(HER)electrocatalysts is crucial for water splitting.Transition metal nitrides(TMNs)are very attractive potential candidates since of high electrical conductivity,robust stability,element rich and high activity.Antiperovskite metal nitrides provide chemical flexibility since two different types of transition metal elements are contained,allowing partial substitution both for A-and M-sites.Herein,we report a novel antiperovskite metal nitride Ag_(x)Ni_(1-x)NNi_(3)(0≤x≤0.80)thin film used as highly effective HER electrocatalysts.Pure phase antiperovskite nitride can be successfully obtained for Ag_(x)Ni_(1-x)NNi_(3)with x less than 0.80.The Ag_(0.76)Ni_(0.24)NNi_(3) towards HER shows an overpotential of 122 mV at 10 mA cm^(-2)in alkaline media.Furthermore,considering the role of Ag for adsorbing hydroxyl groups,chemical engineering has been carried out for designing metal/antiperovskite nitride Ag/Ag_(x)Ni_(1-x)NNi_(3)composite electrocatalysts.The 0.18 Ag/Ag_(0.80)Ni_(0.20)NNi_(3)electrocatalyst shows a mere 13 and 81 mV of overpotential to reach 1 and 10 mA cm^(-2),respectively,showing high durability in alkaline media.These results will provide a novel type of HER catalysts based on antiperovskite metal nitrides and a strategic design for metal/antiperovskite metal nitride composite electrocatalysts for HER in alkaline media.
