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1.
Na3PO4 forms an extensive range of solid solutions with the replacement mechanism, 4Na+ ? Zr4+ and formula Na3–4xZrxPO4:0 < x < 0.20. With increasing x, the conductivity increases markedly and passes through a maximum at with a value of 2.5 × 10?2 ohm?1cm?1 at 300°C. The solid solutions are thermodynamically stable, easily prepared and sinter into dense ceramics at ~1000°C. 相似文献
2.
Masayuki Nagai Satoru Fujitsu Takafumi Kanazawa Hiroaki Yanagida 《Journal of Materials Science》1981,16(6):1633-1642
Two series of solid solutions, Na
x
Ca(1−x)/2Zr2(PO4)3 (NCZP(x), 0⩽x⩽1) and Na
x
Nb1-x
Zr1+x
(PO4)3(NNZP(x), 0⩽x⩽1), were synthesized. They were examined by powder X-ray diffraction, infra-red (i.r.) absorption and Raman scattering.
Ionic conductivities of graphite coated samples were measured. A complete series of solid solutions was formed for NCZP(x), while a second phase was found forx<0.1 for NNZP(x). The i.r. and Raman spectra of their solid solutions consistently showed the formation of PO4 tetrahedra with different geometries. The composition dependence of conductivity is interpreted on the basis of a structural
change around Na+. 相似文献
3.
C. Delmas J.C. Viala R. Olazcuaga G. Le Flem P. Hagenmuller F. Cherkaoui R. Brochu 《Materials Research Bulletin》1981,16(1):83-90
Ionic conductivity measurements in the solid solution Na1+xZr2?xLx(PO4)3 (L = Cr, Yb) have been carried out. The materials have a Nasicon-type structure in a 0 ? x ? xmax.L range (xmax.Cr = 2.0 and xmax.Yb = 1.9). A small monoclinic distortion appears at low temperature for Na3Cr2(PO4)3. As in the Na1+xZr2P3?xSixO12 system a strong increase of the conductivity with rising x has been observed. The results are discussed in connection with temperature and structural parameters. 相似文献
4.
C. Delmas R. Olazcuaga G. Le Flem P. Hagenmuller F. Cherkaoui R. Brochu 《Materials Research Bulletin》1981,16(3):285-290
A crystal chemistry study of the three solid solutions Na1+xZr2?xLx(PO4)3 (L = Cr, In, Yb) has been carried out. A Nasicon-type phase is obtained in the range 0 ? x ? xmax.L with xmax.Cr = 2.0, xmax.In = 1.85, xmaxYb = 1.90 at 950°C. All phases have rhombohedral symmetry except Na3Cr2(PO4)3, where a small monoclinic distortion appears at low temperature. Influence of cationic size, electrostatic repulsion and sodium distribution is discussed. 相似文献
5.
Lithium ion mobility and the superionic phase transition in the Li0.12Na0.88Ta0.4Nb0.6O3 solid solution have been studied using temperature-dependent ionic conductivity measurements and Raman spectroscopy. From the temperature dependences of the conductivity and the width of a Raman line corresponding to Li+ and Na+ vibrations in the AO x (A = Na+, Li+) polyhedra, the average lifetime of the Li+ ion in its equilibrium position and the height of the barrier to hopping have been estimated at ?3.9 × 10?13 s and ?16 kJ/mol, respectively. 相似文献
6.
The existence and ionic conductivity of solid solutions Na1+xM
x
III
Zr2–x(PO4)3 with Nasicon-like structure have been investigated and the results compared with literature data. A limited range of solid solutions is formed with MIII = aluminium, gallium, yttrium, ytterbium, whereas a continuous series is obtained for MIII = chromium, iron, scandium, indium. The pure end member Na3ln2(PO4)3 is reported for the first time; according to powder diffraction data, it is hexagonal witha = 0.8966(1) andc = 2.2104(4) nm. The small monoclinic distortion already known for MIII = chromium, iron and scandium is restricted tox values very close to 2. Ionic conductivity measurements show that for a given value ofx, the mobility of the Na+ ions is strongly influenced both by the ionic radius and the type of electronic structure of the MIII ion. However, no simple correlation can be found. 相似文献
7.
The orthophosphate solid solution phase, Na5?4x Zr1+x(PO4)3:0.04 ? x ? 0.15 has trigonal symmetry with an apparent one dimensional incommensurate superstructure parallel to cHEX. Using selected area electron diffraction patterns as a guide, an indexing scheme for the powder X-ray data has been devised. The parameter varies smoothly with composition from ~ 10.4 at x = 0.04 to ~4.4 at x = 0.11 and is believed to originate in ordering of the extra interstitial Zr4+ ions. The Na+ ion conductivity increases gradually with x and for x = 0.108 varies from ~5×10?8 ohm?1 cm?1 at 25°C to ~1×10?3 ohm?1 cm?1 at 300°C. 相似文献
8.
A. Clearfield R. Guerra A. Oskarsson M.A. Subramanian W. Wang 《Materials Research Bulletin》1983,18(12):1561-1567
Sodium zirconium phosphates of the type Na1+4x Zr2?x (PO4)3 were prepared from mixtures of Na3PO4-ZrO2-ZrP2O7 in sealed platinum tubes at temperatures of 900 – 1200°C. Stoichiometric NaZr2 (PO4)3 (x = 0) was found not to exist. Instead, a solid solution in the range x = 0.02 ? 0.06 was found, with a slight difference in unit cell dimensions obtained. A second solid solution region was found with x = 0.88 – 0.93. At still higher values of x, a stoichiometric phase with hexagonal unit cell dimensions of and was obtained. Finally a phase of composition Na7Zr0.5 (PO4)3 was synthesized at the highest values of x. Attempts to prepare Na5+x ZrSix-P3?xO12 always yielded NASICON and Na7Zr0.5 (PO4)3. 相似文献
9.
The formation mechanisms of Li x Na1 ?x Ta y Nb1 ? y O3 perovskite solid solutions in the Li2CO3-Na2CO3-Nb2O5-Ta2O5 system have been studied by x-ray diffraction, differential thermal analysis, thermogravimetry, IR spectroscopy, and mass spectrometry at temperatures from 300 to 1100°C. The results indicate that the synthesis of Li x Na1 ? x Ta y Nb1 ? y O3 solid solutions involves a complex sequence of consecutive and parallel solid-state reactions. An optimized synthesis procedure for Li x Na1 ? x Ta y Nb1 ? y O3 solid solutions is proposed. 相似文献
10.
J.A. García M.E. Villafuerte-Castrejón J. Andrade R. Valenzuela A.R. West 《Materials Research Bulletin》1984,19(5):649-654
Three extensive new rutile solid solution series have been prepared in which Ti4+ is replaced by a combination of Li+ and a pentavalent cation: Nb5+, Ta5+, Sb5+. The formulae are Ti1?4xLixM3xO2: 0 < x ? 0.15, M = Ta; 0 < x ? 0.17, M = Nb; 0 < x ? 0.12, M = Sb. The solid solutions were characterised by X-ray powder diffraction and density measurements. In addition to the rutile solid solutions, LiNb3O8 forms a limited range of solid solutions, Li1?yNb3?3yTi4yO8: 0 < y ? 0.06. 相似文献
11.
《Materials Research Bulletin》1987,22(5):631-639
Reversible intercalation of sodium in NaTi2(PO4)3 at room temperature can be achieved either chemically or electrochemically. Na3Ti2(PO4)3 is obtained as final product via a two phase mechanism. The non-existence between both extreme compounds of a Na1+xTi2(PO4)3 solid solution seems to result from a topotactic demixtion reaction which requires only Na+ and e− transfers without skeleton bond breaking and recombination. 相似文献
12.
Qiang Fu Bingrui Guo Weibo Hua Angelina Sarapulova Lihua Zhu Peter G. Weidler Alexander Missyul Michael Knapp Helmut Ehrenberg Sonia Dsoke 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(44):2304102
Herein, the electrochemical properties and reaction mechanism of Li3‒2xCaxV2(PO4)3/C (x = 0, 0.5, 1, and 1.5) as negative electrode materials for sodium-ion/potassium-ion batteries (SIBs/PIBs) are investigated. All samples undergo a mixed contribution of diffusion-controlled and pseudocapacitive-type processes in SIBs and PIBs via Trasatti Differentiation Method, while the latter increases with Ca content increase. Among them, Li3V2(PO4)3/C exhibits the highest reversible capacity in SIBs and PIBs, while Ca1.5V2(PO4)3/C shows the best rate performance with a capacity retention of 46% at 20 C in SIBs and 47% at 10 C in PIBs. This study demonstrates that the specific capacity of this type of material in SIBs and PIBs does not increase with the Ca-content as previously observed in lithium-ion system, but the stability and performance at a high C-rate can be improved by replacing Li+ with Ca2+. This indicates that the insertion of different monovalent cations (Na+/K+) can strongly influence the redox reaction and structure evolution of the host materials, due to the larger ion size of Na+ and K+ and their different kinetic properties with respect to Li+. Furthermore, the working mechanism of both LVP/C and Ca1.5V2(PO4)3/C in SIBs are elucidated via in operando synchrotron diffraction and in operando X-ray absorption spectroscopy. 相似文献
13.
Chunyan Lai Zheng Chen Huihui Zhou Yunfeng Lu Hexing Li 《Journal of Materials Science》2015,50(8):3075-3082
Mn-doped Li3V2?x Mn x (PO4)3 nanocrystals with enhanced electrochemical properties for lithium-ion batteries were synthesized by aerosol process successfully. The nanocrystals synthesized from aerosol-assisted spray process have an average particle size smaller than 500 nm, with some initial particle size of about 100 nm. The Mn-doped Li3V2(PO4)3 cathode materials show higher capacity and coulombic efficiency than pure Li3V2(PO4)3 materials. Especially, the Mn-doped Li3V1.94Mn0.06(PO4)3 shows a capacity of 130 mAh/g in the voltage range of 3.0–4.4 V and a coulombic efficiency of 99.5 % at 1C. The results from XRD, SEM, HRTEM, and EIS suggested that lattice changes of Li3V2(PO4)3 due to Mn doping and the fine particles enabled by aerosol-assisted spray process can significantly reduce the charge-transfer resistance and improve the apparent Li+ diffusion coefficient of insertion/desertion in the electrodes, which were the critical reason of better electrochemical performance of Mn-doped Li3V2(PO4)3 cathode materials. 相似文献
14.
Electrical conductivity of Cs<Subscript>3</Subscript>PO<Subscript>4</Subscript> doped with trivalent cations 总被引:1,自引:1,他引:0
Cs3 ? 3x M x PO4 (M = Sc, Y, La, Sm, Nd) solid electrolytes have been synthesized, their phase composition has been determined, and their electrical conductivity has been measured as a function of temperature. In all of the systems, we have identified cesium orthophosphate based solid solutions. Above ~550°C, the solid solutions are isostructural with the high-temperature, cubic phase of Cs3PO4. They offer high cesium ion conductivity owing to the formation of cesium vacancies via 3Cs+ → M3+ substitutions and the decrease in phase transition temperature. The conductivity of the synthesized solid solutions, (4.8?5.6) × 10?3 S/cm at 300°C and (1.6?1.9) × 10?1 S/cm at 800°C, is at the level of earlier studied Cs3 ? 2x M x II PO4 solid electrolytes. 相似文献
15.
MM.Abderrahim Sadel Régnault Von Der Mühll Jean Ravez Paul Hagenmuller 《Materials Research Bulletin》1980,15(9):1281-1286
A solid solution with formulation Na1?xLix(Nb0.6Ta0.4)O3 (0.02 ? x ? 0.20) and a perovskite related structure has been prepared by substituting sodium by lithium in Na(Nb0.6Ta0.4)O3. The ferroelectric Curie temperature increases with x from 308 to 428 K. The pyroelectric properties have been investigated. The high performances may lead to appropriate applications. 相似文献
16.
We have studied the dielectric properties and electrical conductivity of Li
x
Na1 − x
Ta0.1Nb0.9O3 (x = 0.03−0.135) ferroelectric solid solutions at temperatures from 290 to 700 K and frequencies from 25 to 106 Hz. The results demonstrate that charge transport in these materials is due to the Li+ ion and that their conductivity is dominated by volume ion transport. In the temperature range studied, the Li
x
Na1 − x
Ta0.1Nb0.9O3 solid solutions undergo a first-order ferroelectric phase transition close to second order. Increasing the lithium content
enhances features characteristic of second-order transitions. 相似文献
17.
This paper describes a process for the preparation of powders and films of the lithium ion conducting solid electrolyte Li1.3Al0.3Ti1.7(PO4)3 from peroxide solutions. The use of peroxide solutions ensures the preparation of Li1.3Al0.3Ti1.7(PO4)3 with a room-temperature electrical conductivity of (4?C5) × 10?4 S/cm by calcining a precursor at 800°C. The synthesized Li1.3Al0.3Ti1.7(PO4)3 powders were characterized by X-ray diffraction, thermal analysis (DTA/TG), and ionic and electronic conductivity measurements. The growth of Li1.3Al0.3Ti1.7(PO4)3 solid electrolyte films is described. 相似文献
18.
Intercalation complexes Mx(DMSO)y[Cr1?x+3 Crx+2OCl] have been obtained by cathodic reduction of chromium oxide chloride in a solution of M+ (Li+, Na+, K+) in dimethyl-sulfoxide (DMSO). From galvanostatic experiments upper limits for x were determined to be x = 0.12 for Li+ and x = 0.05 for Na+ and K+. Correlations between the degree of reduction (x), ionic radii of M+, amount of solvent intercalation (y), lattice expansion and M+-coordination are discussed.Chromium oxide chloride samples with either chloride deficiency or Cl? by O2? replacement showed a degree of reduction of only x = 0.05 upon Li+-intercalation. 相似文献
19.
Huiteng Tan Lianhua Xu Hongbo Geng Xianhong Rui Chengchao Li Shaoming Huang 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(21)
To further increase the energy and power densities of lithium‐ion batteries (LIBs), monoclinic Li3V2(PO4)3 attracts much attention. However, the intrinsic low electrical conductivity (2.4 × 10?7 S cm?1) and sluggish kinetics become major drawbacks that keep Li3V2(PO4)3 away from meeting its full potential in high rate performance. Recently, significant breakthroughs in electrochemical performance (e.g., rate capability and cycling stability) have been achieved by utilizing advanced nanotechnologies. The nanostructured Li3V2(PO4)3 hybrid cathodes not only improve the electrical conductivity, but also provide high electrode/electrolyte contact interfaces, favorable electron and Li+ transport properties, and good accommodation of strain upon Li+ insertion/extraction. In this Review, light is shed on recent developments in the application of 0D (nanoparticles), 1D (nanowires and nanobelts), 2D (nanoplates and nanosheets), and 3D (nanospheres) Li3V2(PO4)3 for high‐performance LIBs, especially highlighting their synthetic strategies and promising electrochemical properties. Finally, the future prospects of nanostructured Li3V2(PO4)3 cathodes are discussed. 相似文献
20.
N. K. Orlov V. I. Putlayev P. V. Evdokimov T. V. Safronova E. S. Klimashina P. A. Milkin 《Inorganic Materials》2018,54(5):500-508
The resorbability of bioceramics in the Ca3(PO4)2–CaNaPO4–CaKPO4 system is evaluated in an approach involving thermodynamic assessment of solubility and investigation of the dissolution kinetics in model media, in particular in citric acid solutions. Thermodynamic calculation indicates high solubility of the Ca5Na2(PO4)4, α-CaМPO4, β-CaKPO4, and β-СаK0.6Na0.4PO4 phases. Investigation of the dissolution kinetics of ceramics has made it possible to identify two distinct types of behavior of resorbable materials in weakly acidic solutions: with fast resorption kinetics in the case of the phases based on nagelschmidtite solid solutions and α-CaМPO4 disordered high-temperature solid solutions, and with a nearly constant, relatively low dissolution rate and a high solubility limit in the case of β-СaK1 – xNa x -based phases. 相似文献