Hydrogen and lithium,along with their compounds,are crucial materials for nuclear fusion research.High-pressure studies have revealed intricate structural transitions in all these materials.However,research on lithium...Hydrogen and lithium,along with their compounds,are crucial materials for nuclear fusion research.High-pressure studies have revealed intricate structural transitions in all these materials.However,research on lithium hydrides beyond LiH has mostly focused on the low-temperature regime.Here,we use density functional theory and ab initio molecular dynamics simulations to investigate the behavior of LiH_(2),a hydrogen-rich compound,near its melting point.Our study is particularly relevant to the low-pressure region of the compression pathway of lithium hydrides toward fusion.We discovered a premelting superionic phase transition in LiH_(2)that has significant implications for its mass transportation,elastic properties,and sound velocity.The theoretical boundary for the superionic transition and melting temperature was then determined.In contrast,we also found that the primary compound of lithium hydrides,LiH,does not exhibit a superionic transition.These findings have important implications for optimizing the compression path to achieve the ignition condition in inertial confinement fusion research,especially when lithium tritium-deuteride(LiTD)is used as the fuel.展开更多
Since the work of Penrose and Hameroff the possibility is discussed that the location of human memory and consciousness could be connected with tubulin microtubules. If one would use superionic nano-materials rolled u...Since the work of Penrose and Hameroff the possibility is discussed that the location of human memory and consciousness could be connected with tubulin microtubules. If one would use superionic nano-materials rolled up to microtubules with an electrolyte inside the formed channels mediating fast ionic exchange of protons respectively lithium ions, it seems to be possible to write into such materials whole image arrays (pictures) under the action of the complex electromagnetic spectrum that composes these images. The same material and architecture may be recommended for super-computers. Especially microtubules with a protofilament number of 13 are the most important to note. We connected such microtubules before with Fibonacci nets composed of 13 sub-cells that were helically rolled up to deliver suitable channels. Our recent Fibonacci analysis of Wadsley-Roth shear phases such as niobium tungsten oxide , exhibiting channels for ultra-fast lithium-ion diffusion, suggests to use these materials, besides super-battery main application, in form of nanorods or microtubules as effectively working superionic memory devices for computers that work ultra-fast with the complex effectiveness of human brains. Finally, we pose the question, whether dark matter, ever connected with ultrafast movement of ordinary matter, may be responsible for synchronization between interactions of human brains and consciousness.展开更多
Na_(5+x) YAl_x Si_(4-x) O_(12) polycrystalline solid electrolytes are prepared by solid reactions. By the analyses of X-ray, TG and DTA, infrared spectu re, and SEM, the variasion of their density with the composition...Na_(5+x) YAl_x Si_(4-x) O_(12) polycrystalline solid electrolytes are prepared by solid reactions. By the analyses of X-ray, TG and DTA, infrared spectu re, and SEM, the variasion of their density with the composition X are discussed Their electric conductivity in the temperature range of R. T. to 300℃ are determined with electric brigde, and their variasions with the compositions X and temperature are studied. Their activations in the tem- perature range 140℃ to 300℃ are calculated, and their variation with the compositons X are discussed.展开更多
Rare-earth(RE)halide solid electrolytes(HSEs)have been an emerging research area due to their good electrochemical and mechanical properties for all-solid-state lithium batteries(ASSBs).However,only very limited types...Rare-earth(RE)halide solid electrolytes(HSEs)have been an emerging research area due to their good electrochemical and mechanical properties for all-solid-state lithium batteries(ASSBs).However,only very limited types of HSEs have been reported with high performance.In this work,tens of grams of RE-HSE Li_(3)TbBr_(6)(LTbB)was synthesized by a vacuum evaporationassisted method.The as-prepared LTbB displays a high ionic conductivity of 1.7 mS·cm^(-1),a wide electrochemical window,and good formability.Accordingly,the assembled solid lithium-tellurium(Li-Te)battery based on the LTbB HSE exhibits excellent cycling stability up to 600 cycles,which is superior to most previous reports.The processes and the chemicals during the discharge/charge of Li-Te batteries have been studied by various in situ and ex situ characterizations.Theoretical calculations have demonstrated the dominant conductivity contributions of the direct[octahedral]-[octahedral]([Oct]-[Oct])pathway for Li ion migrations in the electrolyte.The Tb sites guarantee efficient electron transfer while the Li 2s orbitals are not affected during migration,leading to a low activation barrier.Therefore,this successful fabrication and application of LTbB have offered a highly competitive solution for solid electrolytes in ASSBs,indicating the great potential of RE-based HSEs in energy devices.展开更多
As a novel class of porous crystalline solids,covalent organic frameworks(COFs)based electrolyte can combine the advantages of both inorganic and polymer electrolytes,leading to such as higher structural stability to ...As a novel class of porous crystalline solids,covalent organic frameworks(COFs)based electrolyte can combine the advantages of both inorganic and polymer electrolytes,leading to such as higher structural stability to inhibit lithium dendrites and better processing facility for improving interfacial contact.However,the ionic components of Li salt tend to be closely associated in the form of ion pairs or even ionic aggregates in the channel of COFs due to strong coulombic interactions,thus resulting in slow ionic diffusion dynamics and low ionic conductivity.Herein,we successfully designed and synthesized a novel single-ion conducting nitrogen hybrid conjugated skeleton(NCS)as all solid electrolyte,whose backbone is consisted with triazine and piperazine rings.A loose bonding between the triazine rings and cations would lower the energy barrier during ions transfer,and electrostatic forces with piperazine rings could“anchor”anions to increase the selectivity during ions transfer.Thus,the NCSelectrolyte exhibits excellent room temperature lithium-ion conductivity up to 1.49 mS·cm−1 and high transference number of 0.84 without employing any solvent,which to the best of our knowledge is one of the highest COF-based electrolytes so far.Moreover,the fabricated all-solid-state lithium metal batteries demonstrate highly attractive properties with quite stable cycling performance over 100 cycles with 82%capacity reservation at 0.5 C.展开更多
Superionic conductors(SCs)exhibiting low ion migration activation energy(Ea)are critical to the performance of electrochemical energy storage devices such as solid-state batteries and fuel cells.However,it is challeng...Superionic conductors(SCs)exhibiting low ion migration activation energy(Ea)are critical to the performance of electrochemical energy storage devices such as solid-state batteries and fuel cells.However,it is challenging to obtain Ea experimentally and theoretically,and the artificial intelligence(AI)method is expected to bring a breakthrough in predicting Ea.Here,we proposed an AI platform(named AI-IMAE)to predict the Ea of cation and anion conductors,including Li^(+),Na^(+),Ag^(+),Al^(3+),Mg^(2+),Zn^(2+),Cu^((2)+),F^(−),and O^(2−),which is~105 times faster than traditional methods.The proposed AI-IMAE is based on crystal graph neural network models and achieves a holistic average absolute error of 0.19 eV,a median absolute error of 0.09 eV,and a Pearson coefficient of 0.92.Using AI-IMAE,we rapidly discovered 316 promising SCs as solid-state electrolytes and 129 SCs as cathode materials from 144,595 inorganic compounds.AI-IMAE is expected to completely solve the challenge of time-consuming Ea prediction and blaze a new trail for large-scale studies of SCs with excellent performance.As more experimental and high-precision theoretical data become available,AI-IMAE can train custom models and transfer the existing models to new models through transfer learning to constantly meet more demands.展开更多
The various theoretical and experimental models for ion conduction mechanism of fast ion conducting （FIC） glass electrolytes have been reported in the present review paper. Some characterization techniques of FIC gl...The various theoretical and experimental models for ion conduction mechanism of fast ion conducting （FIC） glass electrolytes have been reported in the present review paper. Some characterization techniques of FIC glasses are presented. The experimental methods for determination of some ion transport parameters viz ionic conductivity （σ）, ionic mobility （μ）, mobile ion concentration （n）, ionic drift velocity （Vd）, ionic transference number （tion） and activation energies of FIC glasses are explained. The solid state battery fabrication by using some FIC glasses is also reported.展开更多
Sodium-ion batteries(SIBs)have developed rapidly owing to the high natural abundance,wide distribution,and low cost of sodium.Among the various materials used in SIBs,sodium superion conductor(NASICON)-based electrode...Sodium-ion batteries(SIBs)have developed rapidly owing to the high natural abundance,wide distribution,and low cost of sodium.Among the various materials used in SIBs,sodium superion conductor(NASICON)-based electrode materials with remarkable structural stability and high ionic conductivity are one of the most promising candidates for sodium storage electrodes.Nevertheless,the relatively low electronic conductivity of these materials makes them display poor electrochemical performance,significantly limiting their practical application.In recent years,the strategies of enhancing the inherent conductivity of NASICON-based cathode materials have been extensively studied through coating the active material with a conductive carbon layer,reducing the size of the cathode material,combining the cathode material with various carbon materials,and doping elements in the bulk phase.In this paper,we review the recent progress in the development of NASICON-based cathode materials for SIBs in terms of their synthesis,characterization,functional mechanisms,and performance validation/optimization.The advantages and disadvantages of such SIB cathode materials are analyzed,and the relationship between electrode structures and electrochemical performance as well as the strategies for enhancing their electrical conductivity and structural stability is highlighted.Some technical challenges of NASICON-based cathode materials with respect to SIB performance are analyzed,and several future research directions are also proposed for overcoming the challenges toward practical applications.展开更多
Composition regulation of semiconductors can engineer their bandgaps and hence tune their properties. Herein, we report the first synthesis of ternary ZnxCd1-xS semiconductor nanorods by superionic conductor （AgRS）-...Composition regulation of semiconductors can engineer their bandgaps and hence tune their properties. Herein, we report the first synthesis of ternary ZnxCd1-xS semiconductor nanorods by superionic conductor （AgRS）-mediated growth with [（C4H9）2NCS2]2M （M = Zn, ca） as single-source precursors. The compositions of the ZnKCd1-xS nanorods are conveniently tuned over a wide range by adjusting the molar ratio of the corresponding precursors, leading to tunable bandgaps and hence the progressive evolution of the light absorption and photoluminescence spectra. The nanorods present well-distributed size and length, which are controlled by the uniform Ag2S nanoparticles and the fixed amount of the precursors. The results suggest the great potential of superionic conductor-mediated growth in composition regulation and bandgap engineering of chalcogenide nanowires/nanorods.展开更多
I. INTRODUCTIONIn recent years, people have conducted a lot of experiments and valuable theoretical studies on amorphous superionic conductors. From their results, the σ～ω property of amorphous superionic conductor...I. INTRODUCTIONIn recent years, people have conducted a lot of experiments and valuable theoretical studies on amorphous superionic conductors. From their results, the σ～ω property of amorphous superionic conductors can generally be concluded as follows:展开更多
The results from the molecular dynamics simulations on crystalline, superionic, molten and quenched-amorphous states of calcium fluoride system are reported. The Ca++ and F- sublattices are studied by using the method...The results from the molecular dynamics simulations on crystalline, superionic, molten and quenched-amorphous states of calcium fluoride system are reported. The Ca++ and F- sublattices are studied by using the method of bond order parameters. The result shows that both Ca++ and F- sublattices can be described with the bond-orientation normal distribution model. In the superionic phase the Ca++ cations keep their original stable fcc frame, but in the F- case random distortion generates from their original simple cubic (sc) structure. The simulation on the molten phase gives three radial distribution functions that are difficult to separate from the experimental X-ray diffraction data. The simulation of quenched-amorphous state shows that a dense random packing of equivalent spheres centered by Ca++ cations occurs in the system simulated. However, the system quenched is not stable enough because the Ca++ cation and F- anions around it do not form themselves into a certain configuration.展开更多
As an ion conductor, the Al-doped Li1+xAlxGe2-x(PO4)3(LAGP) demonstrates the superionic Li diffusion behavior, however,without the convinced verifications. In this context, the density functional theory(DFT) calculati...As an ion conductor, the Al-doped Li1+xAlxGe2-x(PO4)3(LAGP) demonstrates the superionic Li diffusion behavior, however,without the convinced verifications. In this context, the density functional theory(DFT) calculations are employed to clarify the structural origin of the fast Li ion migration kinetics in LAGP solid electrolytes. The calculated results show that doping of Al leads to an emerging high-energy 36 f Li site, which plays an important role in promoting the Li diffusion and can largely lower the Li ion diffusion energy barrier. Moreover, the Li/Al antisite defect is investigated firstly, with which the Li ions are excited to occupy a relatively high energy site in LAGP. The obvious local structural distortion by Li/Al antisite results in the coordination change upon Li diffusion(lattice field distortion), which facilitates the Li diffusion significantly and is probably the main reason to account for the superionic diffusion phenomenon. Therefore, the occupation of Li at high-energy sites should be an effective method to establish the fast Li diffusion, which implies a rewarding avenue to build better Li-ion batteries.展开更多
Superionic transition(SIT)is an extraordinary phenomenon where a compound attains high ionic conductivity through anomalous disordering of mobile-ion sublattice.Comprehending SIT offers notable prospects for the advan...Superionic transition(SIT)is an extraordinary phenomenon where a compound attains high ionic conductivity through anomalous disordering of mobile-ion sublattice.Comprehending SIT offers notable prospects for the advancement of superionic conductors(SICs)for diverse applications.However,the investigation of SIT is impeded by its intricate and stochastic characteristics,coupled with the absence of adequate methods for characterizing,quantifying,and analyzing its microscopic properties.Here we show that the SIT can be discerned through the dynamic signatures of disordering events underlying the increase in ionic conductivity.The adoption of a dynamic perspective as opposed to the conventional treatment of equilibrium properties brings significant advantage to scrutinize the microscopic characteristics of SIT.Our results show the SIT in the prototypical family of fluorite compounds is characterized by the scaleinvariant disordering dynamics independent of temperature or extent of disorder.The observation of scale-invariance in the absence of external tuning implies that the superionic conduction is self-tuned to criticality by intrinsic dynamics.The connection between ionic diffusion and self-organized criticality provides a novel platform for understanding,analyzing,and manipulating SIT towards better SICs.展开更多
Several emerging energy storage technologies and systems have been demonstrated that feature low cost,high rate capability,and durability for potential use in large-scale grid and high-power applications.Owing to its ...Several emerging energy storage technologies and systems have been demonstrated that feature low cost,high rate capability,and durability for potential use in large-scale grid and high-power applications.Owing to its outstanding ion conductivity,ultrafast Na-ion insertion kinetics,excellent structural stability,and large theoretical capacity,the sodium superionic conductor(NASICON)-structured insertion material NaTi2(PO4)3(NTP)has attracted considerable attention as the optimal electrode material for sodium-ion batteries(SIBs)and Na-ion hybrid capacitors(NHCs).On the basis of recent studies,NaTi2(PO4)3 has raised the rate capabilities,cycling stability,and mass loading of rechargeable SIBs and NHCs to commercially acceptable levels.In this comprehensive review,starting with the structures and electrochemical properties of NTP,we present recent progress in the application of NTP to SIBs,including non-aqueous batteries,aqueous batteries,aqueous batteries with desalination,and sodium-ion hybrid capacitors.After a thorough discussion of the unique NASICON structure of NTP,various strategies for improving the performance of NTP electrode have been presented and summarized in detail.Further,the major challenges and perspectives regarding the prospects for the use of NTP-based electrodes in energy storage systems have also been summarized to offer a guideline for further improving the performance of NTP-based electrodes.展开更多
Relations between the structure, ionic conductivity and dielectric properties of fluoride systems of different structures containing rare earth elements were presented. Superionic conductivities, by fluoride ions, of ...Relations between the structure, ionic conductivity and dielectric properties of fluoride systems of different structures containing rare earth elements were presented. Superionic conductivities, by fluoride ions, of fluorite-structured （MF2-REF3, M=Ba, Pb, RE=La-Lu, Sc, Y）, orthorhombic （REF3, RE=Tb-Er, Y）, tysonite-structured （REF3-MF2, RE=La-Nd, M=Sr）, monoclinic （BaRE2Fs, RE=Ho-Yb, Y） fluoride single crystals and eutectic composites （LiF-REF3, RE=La-Gd, Y） were compared. Anisotropy of electrical properties of crystals with a lower symmetry was explained by modeling optimum ionic paths. For explanation of concentration dependences of fast ionic conductivity, models of aggregation of defects into clusters were proposed. In fluorite-structured crystals, the highest ionic conductivity was found for PbF2：7 mol% ScF3 （at 500 K, σ500=0.13 S/cm）. In tysonite-structured crystals, the highest ionic conductivity was found for LaF3：3 mol% SrF2 （σ500=2.4×10^-2 S/cm）. Different types of coordination polyhedrons and their different linking in orthorhombic and tysonite structure explained large differences between conductivities in both structures. Eutectic systems, prepared as directionally solidified composites, enabled to study some orthorhombic fluoride phases （GdF3, SmF3）, which cannot be prepared as single crystals. An influence of the orthorhombic-tysonite phase transition on the ionic conductivity was shown.展开更多
ZrOCl2·8H2O and ZrO（NO3）2·2H2O were used respectively to synthesize a NASICON solid electrolyte by a sol-gel method. The structure and properties of two samples were characterized by X-ray diffraction （XR...ZrOCl2·8H2O and ZrO（NO3）2·2H2O were used respectively to synthesize a NASICON solid electrolyte by a sol-gel method. The structure and properties of two samples were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and electro-chemical impedance spectroscopy （EIS）. The crystal structure was investigated by the Rietveld refinement. It is found that both the samples contain a monoclinic C2/c phase as the main conductive phase with the lattice parameters ofa=1.56312 nm, b=0.90784 nm and c=0.92203 nm, though a small amount of rhombohedral phase is also detected in the final product. The sample synthesized by ZrO（NO3）2·2H/O contains more monoclinic phase （89.48wt%） than that synthesized by ZrOCl2·SH2O（74.91 wt%）. As expected, the ionic conductivity of the latter is higher than that of the former; however, the activation energy of the latter （0.37 eV） is slightly higher than that of the former （0.35 eV）.展开更多
Na superionic conductor（NASICON） nanoparticles were synthesized by a modified sol-gel method and sintered at a temperature range of 800--1000℃. The performance of the samples was characterized by the analysis metho...Na superionic conductor（NASICON） nanoparticles were synthesized by a modified sol-gel method and sintered at a temperature range of 800--1000℃. The performance of the samples was characterized by the analysis methods of X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR）, and transmission electron microscopy（TEM） as well as conductivity measurement. Compared with those sintered at other temperatures, the NASICON material sintered at 900 ℃ had the best crystalline structure and higher conductivity.展开更多
The recent report of near-ambient superconductivity in the nitrogen-doped lutetium hydride has attracted considerable attention.Subsequent follow-up studies confirmed the pressure-induced color changes in both N-free ...The recent report of near-ambient superconductivity in the nitrogen-doped lutetium hydride has attracted considerable attention.Subsequent follow-up studies confirmed the pressure-induced color changes in both N-free and N-doped LuH_(2) but failed to reproduce superconductivity. It remains a puzzle why the samples in the original report exhibited pronounced resistance anomaly reminiscent of the superconducting transition. Here, we show that percolation of metallic grains with high conductivity through the insulating surfaces in cold-pressed LuH_(2) samples can occasionally produce sharp resistance drops, which even display magnetic field and/or current dependences but stay far from zero resistance. The insulating surface of LuH2grain should be attributed to the modification of hydrogen stoichiometry or the contamination by oxygen/nitrogen, resulting in an increase of resistance by over six orders of magnitude. Such an effect is more significant than that discovered recently in LaH_(3±x), which may indicate that LuH_(2) can be a potential superionic conductor. Our results call for caution in asserting the resistivity drops as superconductivity and invalidate the background subtraction in analyzing the corresponding resistance data.展开更多
Developing cost-effective and reliable solid-state sodium batteries with superior performance is crucial for stationary energy storage.A key component in facilitating their application is a solid-state electrolyte wit...Developing cost-effective and reliable solid-state sodium batteries with superior performance is crucial for stationary energy storage.A key component in facilitating their application is a solid-state electrolyte with high conductivity and stability.Herein,we employed aliovalent cation substitution to enhance ionic conductivity while preserving the crystal structure.Optimized substitution of Y^(3+)with Zr^(4+)in Na_(5)YSi_(4)O_(12) introduced Naþion vacancies,resulting in high bulk and total conductivities of up to 6.5 and 3.3 mS cm^(-1),respectively,at room temperature with the composition Na_(4.92)Y_(0.92)Zr_(0.08)Si_(4)O_(12)(NYZS).NYZS shows exceptional electrochemical stability(up to 10 V vs.Naþ/Na),favorable interfacial compatibility with Na,and an excellent critical current density of 2.4 mA cm^(-2).The enhanced conductivity of Naþions in NYZS was elucidated using solid-state nuclear magnetic resonance techniques and theoretical simulations,revealing two migration routes facilitated by the synergistic effect of increased Naþion vacancies and improved chemical environment due to Zr^(4+)substitution.NYZS extends the list of suitable solid-state electrolytes and enables the facile synthesis of stable,low-cost Naþion silicate electrolytes.展开更多
Sodium superionic conductor(NASICON)-type compounds have been regarded as promising cathodes for sodium-ion batteries(SIBs)due to their favorable ionic conductivity and robust structural stability.However,their high c...Sodium superionic conductor(NASICON)-type compounds have been regarded as promising cathodes for sodium-ion batteries(SIBs)due to their favorable ionic conductivity and robust structural stability.However,their high cost and relatively low energy density restrict their further practical application,which can be tailored by widening the operating voltages with earth-abundant elements such as Mn.Here,we propose a rational strategy of infusing Mn element in NASICON frameworks with sufficiently mobile sodium ions that enhances the redox voltage and ionic migration activity.The optimized structure of Na3.5Mn0.5V1.5(PO4)3/C is achieved and investigated systematically to be a durable cathode(76.6%capacity retention over 5,000 cycles at 20 C)for SIBs,which exhibits high reversible capacity(113.1 mAh·g^−1 at 0.5 C)with relatively low volume change(7.6%).Importantly,its high-areal-loading and temperature-resistant sodium ion storage properties are evaluated,and the full-cell configuration is demonstrated.This work indicates that this Na3.5Mn0.5V1.5(PO4)3/C composite could be a promising cathode candidate for SIBs.展开更多
基金Project supported by the National Key Research and Development Program of China(Grant No.2021YFB3802300)the National Natural Science Foundation of China(Grant No.11672274)the NSAF(Grant No.U1730248)。
文摘Hydrogen and lithium,along with their compounds,are crucial materials for nuclear fusion research.High-pressure studies have revealed intricate structural transitions in all these materials.However,research on lithium hydrides beyond LiH has mostly focused on the low-temperature regime.Here,we use density functional theory and ab initio molecular dynamics simulations to investigate the behavior of LiH_(2),a hydrogen-rich compound,near its melting point.Our study is particularly relevant to the low-pressure region of the compression pathway of lithium hydrides toward fusion.We discovered a premelting superionic phase transition in LiH_(2)that has significant implications for its mass transportation,elastic properties,and sound velocity.The theoretical boundary for the superionic transition and melting temperature was then determined.In contrast,we also found that the primary compound of lithium hydrides,LiH,does not exhibit a superionic transition.These findings have important implications for optimizing the compression path to achieve the ignition condition in inertial confinement fusion research,especially when lithium tritium-deuteride(LiTD)is used as the fuel.
文摘Since the work of Penrose and Hameroff the possibility is discussed that the location of human memory and consciousness could be connected with tubulin microtubules. If one would use superionic nano-materials rolled up to microtubules with an electrolyte inside the formed channels mediating fast ionic exchange of protons respectively lithium ions, it seems to be possible to write into such materials whole image arrays (pictures) under the action of the complex electromagnetic spectrum that composes these images. The same material and architecture may be recommended for super-computers. Especially microtubules with a protofilament number of 13 are the most important to note. We connected such microtubules before with Fibonacci nets composed of 13 sub-cells that were helically rolled up to deliver suitable channels. Our recent Fibonacci analysis of Wadsley-Roth shear phases such as niobium tungsten oxide , exhibiting channels for ultra-fast lithium-ion diffusion, suggests to use these materials, besides super-battery main application, in form of nanorods or microtubules as effectively working superionic memory devices for computers that work ultra-fast with the complex effectiveness of human brains. Finally, we pose the question, whether dark matter, ever connected with ultrafast movement of ordinary matter, may be responsible for synchronization between interactions of human brains and consciousness.
文摘Na_(5+x) YAl_x Si_(4-x) O_(12) polycrystalline solid electrolytes are prepared by solid reactions. By the analyses of X-ray, TG and DTA, infrared spectu re, and SEM, the variasion of their density with the composition X are discussed Their electric conductivity in the temperature range of R. T. to 300℃ are determined with electric brigde, and their variasions with the compositions X and temperature are studied. Their activations in the tem- perature range 140℃ to 300℃ are calculated, and their variation with the compositons X are discussed.
基金This work was supported by the National Key R&D Program of China(No.2021YFA1501101)the Natural Science Foundation of China(No.21971117)+11 种基金Functional Research Funds for the Central Universities,Nankai University(No.63186005)Tianjin Key Lab for Rare Earth Materials and Applications(No.ZB19500202)the National Natural Science Foundation of China/Research Grant Council Joint Research Scheme(No.N_PolyU502/21)111 Project(No.B18030)from ChinaOutstanding Youth Project of Tianjin Natural Science Foundation(No.20JCJQJC00130)Key Project of Tianjin Natural Science Foundation(No.20JCZDJC00650)the Projects of Strategic Importance of The Hong Kong Polytechnic University(No.1-ZE2V)Shenzhen Fundamental Research Scheme-General Program(No.JCYJ20220531090807017)National Postdoctoral Program for Innovative Talents(No.BX20220157)Open Foundation of State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures(No.2022GXYSOF07)Haihe Laboratory of Sustainable Chemical Transformations.B.L.H.also thanks the support from Research Centre for Carbon-Strategic Catalysis(RCCSC),Research Institute for Smart Energy(RISE)Research Institute for Intelligent Wearable Systems(RI-IWEAR)of the Hong Kong Polytechnic University.
文摘Rare-earth(RE)halide solid electrolytes(HSEs)have been an emerging research area due to their good electrochemical and mechanical properties for all-solid-state lithium batteries(ASSBs).However,only very limited types of HSEs have been reported with high performance.In this work,tens of grams of RE-HSE Li_(3)TbBr_(6)(LTbB)was synthesized by a vacuum evaporationassisted method.The as-prepared LTbB displays a high ionic conductivity of 1.7 mS·cm^(-1),a wide electrochemical window,and good formability.Accordingly,the assembled solid lithium-tellurium(Li-Te)battery based on the LTbB HSE exhibits excellent cycling stability up to 600 cycles,which is superior to most previous reports.The processes and the chemicals during the discharge/charge of Li-Te batteries have been studied by various in situ and ex situ characterizations.Theoretical calculations have demonstrated the dominant conductivity contributions of the direct[octahedral]-[octahedral]([Oct]-[Oct])pathway for Li ion migrations in the electrolyte.The Tb sites guarantee efficient electron transfer while the Li 2s orbitals are not affected during migration,leading to a low activation barrier.Therefore,this successful fabrication and application of LTbB have offered a highly competitive solution for solid electrolytes in ASSBs,indicating the great potential of RE-based HSEs in energy devices.
基金We thank the financial support from the Natural Science Foundation of Shandong(Nos.ZR2020JQ21 and ZR2021ZD24)National Natural Science Foundation of China(Nos.51873231 and 22138013)+1 种基金Taishan Scholar Project(No.tsqn201909062)the Technology Foundation of Shandong Energy Group Co.,LTD.(YKZB2020-176,YKKJ2019AJ08JG-R63)。
文摘As a novel class of porous crystalline solids,covalent organic frameworks(COFs)based electrolyte can combine the advantages of both inorganic and polymer electrolytes,leading to such as higher structural stability to inhibit lithium dendrites and better processing facility for improving interfacial contact.However,the ionic components of Li salt tend to be closely associated in the form of ion pairs or even ionic aggregates in the channel of COFs due to strong coulombic interactions,thus resulting in slow ionic diffusion dynamics and low ionic conductivity.Herein,we successfully designed and synthesized a novel single-ion conducting nitrogen hybrid conjugated skeleton(NCS)as all solid electrolyte,whose backbone is consisted with triazine and piperazine rings.A loose bonding between the triazine rings and cations would lower the energy barrier during ions transfer,and electrostatic forces with piperazine rings could“anchor”anions to increase the selectivity during ions transfer.Thus,the NCSelectrolyte exhibits excellent room temperature lithium-ion conductivity up to 1.49 mS·cm−1 and high transference number of 0.84 without employing any solvent,which to the best of our knowledge is one of the highest COF-based electrolytes so far.Moreover,the fabricated all-solid-state lithium metal batteries demonstrate highly attractive properties with quite stable cycling performance over 100 cycles with 82%capacity reservation at 0.5 C.
基金J.L.thanks financial supports from the National Key R&D Program of China(No.2021YFC2100100)the National Natural Science Foundation of China(No.21901157)+1 种基金the SJTU Global Strategic Partnership Fund(No.2020 SJTU-HUJI)the National Key Laboratory of Science and Technology on Micro/Nano Fabrication,China.
文摘Superionic conductors(SCs)exhibiting low ion migration activation energy(Ea)are critical to the performance of electrochemical energy storage devices such as solid-state batteries and fuel cells.However,it is challenging to obtain Ea experimentally and theoretically,and the artificial intelligence(AI)method is expected to bring a breakthrough in predicting Ea.Here,we proposed an AI platform(named AI-IMAE)to predict the Ea of cation and anion conductors,including Li^(+),Na^(+),Ag^(+),Al^(3+),Mg^(2+),Zn^(2+),Cu^((2)+),F^(−),and O^(2−),which is~105 times faster than traditional methods.The proposed AI-IMAE is based on crystal graph neural network models and achieves a holistic average absolute error of 0.19 eV,a median absolute error of 0.09 eV,and a Pearson coefficient of 0.92.Using AI-IMAE,we rapidly discovered 316 promising SCs as solid-state electrolytes and 129 SCs as cathode materials from 144,595 inorganic compounds.AI-IMAE is expected to completely solve the challenge of time-consuming Ea prediction and blaze a new trail for large-scale studies of SCs with excellent performance.As more experimental and high-precision theoretical data become available,AI-IMAE can train custom models and transfer the existing models to new models through transfer learning to constantly meet more demands.
基金DST,New Delhi for providing financial assistance through the Fast Track Young Scientist Research Project(No.SR/FTP/PS-23/2009)
文摘The various theoretical and experimental models for ion conduction mechanism of fast ion conducting （FIC） glass electrolytes have been reported in the present review paper. Some characterization techniques of FIC glasses are presented. The experimental methods for determination of some ion transport parameters viz ionic conductivity （σ）, ionic mobility （μ）, mobile ion concentration （n）, ionic drift velocity （Vd）, ionic transference number （tion） and activation energies of FIC glasses are explained. The solid state battery fabrication by using some FIC glasses is also reported.
基金the National Natural Science Foundation of China(Nos.51602193,21601122,21905169)the Belt and Road Initiatives International Cooperation Project(No.20640770300)+5 种基金the Shanghai“Chen Guang”Project(16CG63)the Shanghai Local Universities Capacity Building Project of Science and Technology Innovation Action Program(21010501700)the Shanghai Sailing Program(No.18YF1408600)the Fundamental Research Funds for the Central Universities(WD1817002)the EPSRC(EP/R023581/1,EP/P009050/1,EP/V027433/1)the Royal Society(RGS/R1/211080).
文摘Sodium-ion batteries(SIBs)have developed rapidly owing to the high natural abundance,wide distribution,and low cost of sodium.Among the various materials used in SIBs,sodium superion conductor(NASICON)-based electrode materials with remarkable structural stability and high ionic conductivity are one of the most promising candidates for sodium storage electrodes.Nevertheless,the relatively low electronic conductivity of these materials makes them display poor electrochemical performance,significantly limiting their practical application.In recent years,the strategies of enhancing the inherent conductivity of NASICON-based cathode materials have been extensively studied through coating the active material with a conductive carbon layer,reducing the size of the cathode material,combining the cathode material with various carbon materials,and doping elements in the bulk phase.In this paper,we review the recent progress in the development of NASICON-based cathode materials for SIBs in terms of their synthesis,characterization,functional mechanisms,and performance validation/optimization.The advantages and disadvantages of such SIB cathode materials are analyzed,and the relationship between electrode structures and electrochemical performance as well as the strategies for enhancing their electrical conductivity and structural stability is highlighted.Some technical challenges of NASICON-based cathode materials with respect to SIB performance are analyzed,and several future research directions are also proposed for overcoming the challenges toward practical applications.
文摘Composition regulation of semiconductors can engineer their bandgaps and hence tune their properties. Herein, we report the first synthesis of ternary ZnxCd1-xS semiconductor nanorods by superionic conductor （AgRS）-mediated growth with [（C4H9）2NCS2]2M （M = Zn, ca） as single-source precursors. The compositions of the ZnKCd1-xS nanorods are conveniently tuned over a wide range by adjusting the molar ratio of the corresponding precursors, leading to tunable bandgaps and hence the progressive evolution of the light absorption and photoluminescence spectra. The nanorods present well-distributed size and length, which are controlled by the uniform Ag2S nanoparticles and the fixed amount of the precursors. The results suggest the great potential of superionic conductor-mediated growth in composition regulation and bandgap engineering of chalcogenide nanowires/nanorods.
文摘I. INTRODUCTIONIn recent years, people have conducted a lot of experiments and valuable theoretical studies on amorphous superionic conductors. From their results, the σ～ω property of amorphous superionic conductors can generally be concluded as follows:
基金Project supported by the National Natural Science Foundation of China.
文摘The results from the molecular dynamics simulations on crystalline, superionic, molten and quenched-amorphous states of calcium fluoride system are reported. The Ca++ and F- sublattices are studied by using the method of bond order parameters. The result shows that both Ca++ and F- sublattices can be described with the bond-orientation normal distribution model. In the superionic phase the Ca++ cations keep their original stable fcc frame, but in the F- case random distortion generates from their original simple cubic (sc) structure. The simulation on the molten phase gives three radial distribution functions that are difficult to separate from the experimental X-ray diffraction data. The simulation of quenched-amorphous state shows that a dense random packing of equivalent spheres centered by Ca++ cations occurs in the system simulated. However, the system quenched is not stable enough because the Ca++ cation and F- anions around it do not form themselves into a certain configuration.
基金supported by the National Key Research and Development Program of China (Grant No. 2019YFA0705700)National Natural Science Foundation of China (Grant No. 11704019)+1 种基金the Hundreds of Talents Program of Sun Yat-sen Universitythe Fundamental Research Funds for the Central Universities。
文摘As an ion conductor, the Al-doped Li1+xAlxGe2-x(PO4)3(LAGP) demonstrates the superionic Li diffusion behavior, however,without the convinced verifications. In this context, the density functional theory(DFT) calculations are employed to clarify the structural origin of the fast Li ion migration kinetics in LAGP solid electrolytes. The calculated results show that doping of Al leads to an emerging high-energy 36 f Li site, which plays an important role in promoting the Li diffusion and can largely lower the Li ion diffusion energy barrier. Moreover, the Li/Al antisite defect is investigated firstly, with which the Li ions are excited to occupy a relatively high energy site in LAGP. The obvious local structural distortion by Li/Al antisite results in the coordination change upon Li diffusion(lattice field distortion), which facilitates the Li diffusion significantly and is probably the main reason to account for the superionic diffusion phenomenon. Therefore, the occupation of Li at high-energy sites should be an effective method to establish the fast Li diffusion, which implies a rewarding avenue to build better Li-ion batteries.
文摘Superionic transition(SIT)is an extraordinary phenomenon where a compound attains high ionic conductivity through anomalous disordering of mobile-ion sublattice.Comprehending SIT offers notable prospects for the advancement of superionic conductors(SICs)for diverse applications.However,the investigation of SIT is impeded by its intricate and stochastic characteristics,coupled with the absence of adequate methods for characterizing,quantifying,and analyzing its microscopic properties.Here we show that the SIT can be discerned through the dynamic signatures of disordering events underlying the increase in ionic conductivity.The adoption of a dynamic perspective as opposed to the conventional treatment of equilibrium properties brings significant advantage to scrutinize the microscopic characteristics of SIT.Our results show the SIT in the prototypical family of fluorite compounds is characterized by the scaleinvariant disordering dynamics independent of temperature or extent of disorder.The observation of scale-invariance in the absence of external tuning implies that the superionic conduction is self-tuned to criticality by intrinsic dynamics.The connection between ionic diffusion and self-organized criticality provides a novel platform for understanding,analyzing,and manipulating SIT towards better SICs.
基金supported by the National Natural Science Foundation of China (No. 51302079)the Natural Science Foundation of Hunan Province (No. 2017JJ1008)the Key Research and Development Program of Hunan Province of China under Grant 2018GK2031
文摘Several emerging energy storage technologies and systems have been demonstrated that feature low cost,high rate capability,and durability for potential use in large-scale grid and high-power applications.Owing to its outstanding ion conductivity,ultrafast Na-ion insertion kinetics,excellent structural stability,and large theoretical capacity,the sodium superionic conductor(NASICON)-structured insertion material NaTi2(PO4)3(NTP)has attracted considerable attention as the optimal electrode material for sodium-ion batteries(SIBs)and Na-ion hybrid capacitors(NHCs).On the basis of recent studies,NaTi2(PO4)3 has raised the rate capabilities,cycling stability,and mass loading of rechargeable SIBs and NHCs to commercially acceptable levels.In this comprehensive review,starting with the structures and electrochemical properties of NTP,we present recent progress in the application of NTP to SIBs,including non-aqueous batteries,aqueous batteries,aqueous batteries with desalination,and sodium-ion hybrid capacitors.After a thorough discussion of the unique NASICON structure of NTP,various strategies for improving the performance of NTP electrode have been presented and summarized in detail.Further,the major challenges and perspectives regarding the prospects for the use of NTP-based electrodes in energy storage systems have also been summarized to offer a guideline for further improving the performance of NTP-based electrodes.
基金the Scientific Grant Agency VEGA, Slovak Republic (1/2100/05 and 1/0173/08)
文摘Relations between the structure, ionic conductivity and dielectric properties of fluoride systems of different structures containing rare earth elements were presented. Superionic conductivities, by fluoride ions, of fluorite-structured （MF2-REF3, M=Ba, Pb, RE=La-Lu, Sc, Y）, orthorhombic （REF3, RE=Tb-Er, Y）, tysonite-structured （REF3-MF2, RE=La-Nd, M=Sr）, monoclinic （BaRE2Fs, RE=Ho-Yb, Y） fluoride single crystals and eutectic composites （LiF-REF3, RE=La-Gd, Y） were compared. Anisotropy of electrical properties of crystals with a lower symmetry was explained by modeling optimum ionic paths. For explanation of concentration dependences of fast ionic conductivity, models of aggregation of defects into clusters were proposed. In fluorite-structured crystals, the highest ionic conductivity was found for PbF2：7 mol% ScF3 （at 500 K, σ500=0.13 S/cm）. In tysonite-structured crystals, the highest ionic conductivity was found for LaF3：3 mol% SrF2 （σ500=2.4×10^-2 S/cm）. Different types of coordination polyhedrons and their different linking in orthorhombic and tysonite structure explained large differences between conductivities in both structures. Eutectic systems, prepared as directionally solidified composites, enabled to study some orthorhombic fluoride phases （GdF3, SmF3）, which cannot be prepared as single crystals. An influence of the orthorhombic-tysonite phase transition on the ionic conductivity was shown.
基金supported by the National Natural Science Foundation of China (No.50974012)Program Changjiang Scholars and Innovative Research Team in Universities (No.0708)
文摘ZrOCl2·8H2O and ZrO（NO3）2·2H2O were used respectively to synthesize a NASICON solid electrolyte by a sol-gel method. The structure and properties of two samples were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and electro-chemical impedance spectroscopy （EIS）. The crystal structure was investigated by the Rietveld refinement. It is found that both the samples contain a monoclinic C2/c phase as the main conductive phase with the lattice parameters ofa=1.56312 nm, b=0.90784 nm and c=0.92203 nm, though a small amount of rhombohedral phase is also detected in the final product. The sample synthesized by ZrO（NO3）2·2H/O contains more monoclinic phase （89.48wt%） than that synthesized by ZrOCl2·SH2O（74.91 wt%）. As expected, the ionic conductivity of the latter is higher than that of the former; however, the activation energy of the latter （0.37 eV） is slightly higher than that of the former （0.35 eV）.
基金Supported by the Major International Collaborative Project of the National Natural Science Foundation of China(No. 60574096)the Distinguished Young Scholars(No.60625301).
文摘Na superionic conductor（NASICON） nanoparticles were synthesized by a modified sol-gel method and sintered at a temperature range of 800--1000℃. The performance of the samples was characterized by the analysis methods of X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR）, and transmission electron microscopy（TEM） as well as conductivity measurement. Compared with those sintered at other temperatures, the NASICON material sintered at 900 ℃ had the best crystalline structure and higher conductivity.
基金supported by the National Natural Science Foundation of China (Grant Nos. 12025408, 11921004, 11834016, and 11888101)the Beijing Natural Science Foundation (Grant No. Z190008)+1 种基金the National Key R&D Program of China (Grant Nos. 2021YFA1400200, and 2021YFA1400300)the Strategic Priority Research Program of CAS (Grant No. XDB33000000)。
文摘The recent report of near-ambient superconductivity in the nitrogen-doped lutetium hydride has attracted considerable attention.Subsequent follow-up studies confirmed the pressure-induced color changes in both N-free and N-doped LuH_(2) but failed to reproduce superconductivity. It remains a puzzle why the samples in the original report exhibited pronounced resistance anomaly reminiscent of the superconducting transition. Here, we show that percolation of metallic grains with high conductivity through the insulating surfaces in cold-pressed LuH_(2) samples can occasionally produce sharp resistance drops, which even display magnetic field and/or current dependences but stay far from zero resistance. The insulating surface of LuH2grain should be attributed to the modification of hydrogen stoichiometry or the contamination by oxygen/nitrogen, resulting in an increase of resistance by over six orders of magnitude. Such an effect is more significant than that discovered recently in LaH_(3±x), which may indicate that LuH_(2) can be a potential superionic conductor. Our results call for caution in asserting the resistivity drops as superconductivity and invalidate the background subtraction in analyzing the corresponding resistance data.
基金the China Scholarship Council (CSC,Grant Nos.201906200023,201906200016 and 201808080137,respectively)for financial supportfunding from the European Union's Horizon 2020 research,innovation program under the Marie Sklodowska-Curie grant agreement (No.101034329)the WINNING Normandy Program supported by the Normandy Region,France.
文摘Developing cost-effective and reliable solid-state sodium batteries with superior performance is crucial for stationary energy storage.A key component in facilitating their application is a solid-state electrolyte with high conductivity and stability.Herein,we employed aliovalent cation substitution to enhance ionic conductivity while preserving the crystal structure.Optimized substitution of Y^(3+)with Zr^(4+)in Na_(5)YSi_(4)O_(12) introduced Naþion vacancies,resulting in high bulk and total conductivities of up to 6.5 and 3.3 mS cm^(-1),respectively,at room temperature with the composition Na_(4.92)Y_(0.92)Zr_(0.08)Si_(4)O_(12)(NYZS).NYZS shows exceptional electrochemical stability(up to 10 V vs.Naþ/Na),favorable interfacial compatibility with Na,and an excellent critical current density of 2.4 mA cm^(-2).The enhanced conductivity of Naþions in NYZS was elucidated using solid-state nuclear magnetic resonance techniques and theoretical simulations,revealing two migration routes facilitated by the synergistic effect of increased Naþion vacancies and improved chemical environment due to Zr^(4+)substitution.NYZS extends the list of suitable solid-state electrolytes and enables the facile synthesis of stable,low-cost Naþion silicate electrolytes.
基金This work was supported by the National Natural Science Foundation of China(Nos.51872334 and 51932011)the Innovation-Driven Project of Central South University(No.2020CX024).
文摘Sodium superionic conductor(NASICON)-type compounds have been regarded as promising cathodes for sodium-ion batteries(SIBs)due to their favorable ionic conductivity and robust structural stability.However,their high cost and relatively low energy density restrict their further practical application,which can be tailored by widening the operating voltages with earth-abundant elements such as Mn.Here,we propose a rational strategy of infusing Mn element in NASICON frameworks with sufficiently mobile sodium ions that enhances the redox voltage and ionic migration activity.The optimized structure of Na3.5Mn0.5V1.5(PO4)3/C is achieved and investigated systematically to be a durable cathode(76.6%capacity retention over 5,000 cycles at 20 C)for SIBs,which exhibits high reversible capacity(113.1 mAh·g^−1 at 0.5 C)with relatively low volume change(7.6%).Importantly,its high-areal-loading and temperature-resistant sodium ion storage properties are evaluated,and the full-cell configuration is demonstrated.This work indicates that this Na3.5Mn0.5V1.5(PO4)3/C composite could be a promising cathode candidate for SIBs.
