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1.
《Ceramics International》2023,49(20):32903-32912
The urgent need for high-performance sodium batteries has drawn great attention to the development of novel solid-state electrolyte systems. However, it is still a great challenge to obtain excellent ionic conductivity and interfacial stability performance for most solid-state electrolytes. In this study, a new NASICON-type solid-state electrolyte Na3.1+xZr2−xScxSi2.1P0.9O12 (donated as NZSSP, x = 0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3) was successfully prepared by solid-phase method. Due to the aliovalent substitution of Sc3+/Si4+, the phase transition or unwanted rhombohedral phase is effectively suppressed, the Na+ transport channel bottlenecks are greatly enlarged, and the concentration of Na+ is largely increased, giving rise to the significant improvement of the ionic conductivity and stability of NZSSP solid-state electrolyte. The Na3.35Zr1.75Sc0.25Si2.1P0.9O12 solid-state electrolyte has an ultra-high ionic conductivity of 4.92 mS cm−1 at room temperature. Meanwhile, it shows an excellent sodium plating/stripping stability by the optimization of the Na+ transport channel. The critical current density of the Na//Na3.35Zr1.75Sc0.25Si2.1P0.9O12//Na symmetric battery is achieved up to 1.0 mA cm−2, and it can stably cycle for nearly 3000 h at 0.1 mA cm−2 or 1000 h at 0.5 mA cm−2 at room temperature. A detailed analysis of these aliovalent dual element substitution samples has been performed, and the mechanism of the conductivity enhancement is discussed systematically. This study can provide a feasible method to improve the ionic conductivity and electrochemical stability of NZSP materials and paves a way for the application of all-solid-state sodium batteries. 相似文献
2.
《Journal of the European Ceramic Society》2007,27(7):2577-2589
Undoped-BaTiO3 powder prepared from the mixed oxide route (0 h sample) has been attrition milled using yttria-stabilized ZrO2 milling media for 0.5–3 h prior to formation of dense ceramics. Both isovalent (Zr4+ → Ti4+) and aliovalent (Y3+ → Ba2+) dopant contamination effects have been observed. Systematic changes occur in the lattice parameters, polymorphic phase transition temperatures and dielectric properties below the Curie temperature for 0–2 h attrition milled powders and these are attributed primarily to an ion-size effect associated with Zr-doping on the Ti-site due to milling media contamination. The bulk conductivity of attrition milled samples at high temperature decreases by ∼2–3 orders of magnitude compared to 0 h samples and the activation energy associated with bulk conduction increases from ∼1 eV for 0 and 0.5 h samples to 1.4 eV for 3 h samples. The change in bulk conductivity and conduction mechanism for the attrition milled samples is attributed to aliovalent Y3+ dopant contamination from the milling media. 相似文献
3.
《Ceramics International》2017,43(15):11879-11884
Li6.5La3Zr1.5Nb0.5O12 (LLZN) garnet-type structure was synthesized at low temperature with B2O3 addition by solid state reaction method. The effects of B2O3 content on the formation, microstructure, ionic conductivity and activation energy of the LLZN solid electrolytes have been investigated by X-Ray diffraction (XRD), scanning electron microscopy (SEM) and alternate current (AC) impedance spectroscopy. The cubic LLZN phase was obtained after calcining at 850 °C for 6 h and no phase evolution was observed after sintering at 1100 °C for 6 h. The relative density and lithium ion conductivity increased first and then decreased with increasing B2O3 content, reaching the maximum value of 92.4% and 1.86×10−4 S cm−1 respectively in the sample with 1.4 wt% B2O3. By contrast, the activation energy reached a minimum value of ~31.5 kJ mol−1. 相似文献
4.
《Ceramics International》2017,43(7):5642-5646
Perovskite-structured Li3/8Sr7/16Zr1/4Nb3/4O3 solid-state Lithium-conductors were prepared by conventional solid-state reaction method. Influence of sintering aids (Al2O3, B2O3) and excess Lithium on structure and electrical properties of Li3/8Sr7/16Zr1/4Nb3/4O3 (LSNZ) has been investigated. Their crystal structure and microstructure were characterized by X-ray diffraction analysis and scanning electron microscope, respectively. The conductivity and electronic conductivity were evaluated by AC-impedance spectra and potentiostatic polarization experiment. All sintered compounds are cubic perovskite structure. Optimal amount of excess Li2CO3 was chosen as 20 wt% because of the total conductivity of LSNZ-20% was as high as 1.6×10−5 S cm−1 at 30 °C and 1.1×10−4 S cm−1 at 100 °C, respectively. Electronic conductivity of LSNZ-20% is 2.93×10−8 S cm−1, nearly 3 orders of magnitude lower than ionic conductivity. The density of solid electrolytes appears to be increased by the addition of sintering aids. The addition of B2O3 leads to a considerable increase of the total conductivity and the enhancement of conductivity is attributed to the decrease of grain-boundary resistance. Among these compounds, LSNZ-1 wt%B2O3 has lower activation energy of 0.34 eV and the highest conductivity of 1.98×10−5 S cm−1 at 30 °C. 相似文献
5.
Jing Luo Gaolei Zhao Wenjiang Qiang Bingxin Huang 《Journal of the American Ceramic Society》2022,105(5):3428-3437
NASICON solid electrolyte Na3Zr2Si2PO12 (NZSP) exhibits high chemical stability and can be utilized as cladding materials of cathodes to improve battery cycle stability. However, the electronic conductivity of NZSP is extremely low (∼10−9 S cm−1), which will hinder the electron conduction of cathode materials. To address this issue, the electronic conductivity of NZSP is improved by doping with transition metal elements (Co, Fe, Ni). Co-doped NZSP has an electronic conductivity of 5.03 × 10−6 S cm−1. On the other hand, the ionic conductivity of doped samples remains stable, even slightly increased. The mechanical properties of pristine and doped samples are characterized with a micro indenter, which is also a key parameter for coating materials. 相似文献
6.
《Journal of the European Ceramic Society》2023,43(10):4443-4450
Na3Zr2Si2PO12 (NZSP) solid-state electrolyte is considered one of the most promising solid-state electrolyte because of their excellent electrochemical and thermal stability. Even though, the low conductivity of NZSP solid-state electrolytes hinders practical application. Therefore, an anions/cations co-assisting strategy is proposed by introducing the Zn2+ and F−. The influence of adding different amounts of Zn2+ and F− on the Na+ conductivity of NZSP was investigated computationally and experimentally. The Zn2+/F− co-assisting (Na3.3Zr1.85Zn0.15Si2PO12) solid-state electrolyte exhibits the ionic conductivity of 0.722 mS cm−1 at 30 °C, and the activation energy of ∼0.237 eV. Its applicability in a solid-state battery is tested, and the assembled Na/Na3V2(PO4)3 (NVP) battery exhibits an outstanding electrochemical performance of 98.4% capacity retention after being cycled at 0.5 C. Moreover, DFT calculations also have been used to demonstrate the effect of doping on the crystal structure and space migration energy barrier. This research provides new ideas for improving the electrochemical properties of inorganic solid electrolytes. 相似文献
7.
Li3/8Sr7/16-3x/2LaxZr1/4Nb3/4O3 (x = 0, 0.05, 0.10, 0.15, 0.20) were synthesized using the conventional solid-state reaction method. In order to increase the vacancy concentration, La3+ was doped on the Sr2+ site. Crystal structures of doped samples were characterized by X-ray diffraction. Except, perovskite-type Li3/8Sr7/16-3x/2LaxZr1/4Nb3/4O3 (x = 0, 0.05, 0.10, 0.15) samples were fabricated by heat treatment at 1250 °C, 1275 °C, 1275 °C and 1275 °C, respectively, for 15 h. Lattice sizes decreased with the increase of doping amounts because of the smaller ion radius of La3+ compared to that of Sr2+. Ionic conductivities of the samples were measured by AC impedance spectroscopy. The results showed that the ionic conductivity increases at first and then decreases with raising doping amounts and sintering temperatures. So the optimized composition Li3/8Sr7/16-3x/2LaxZr1/4Nb3/4O3 (x = 0.05) sintered at 1275 °C was selected with the highest total conductivity of 3.33 × 10?5 S cm?1at 30 °C and an activation energy of 0.27 eV. Additionally, potentiostatic polarization test was used to evaluate the electronic conductivity. The optimal composition Li3/8Sr7/16-3x/2LaxZr1/4Nb3/4O3 (x = 0.05) as a possible Li-ion conducting solid electrolyte has an electronic conductivity of only 8.39 × 10?9 S cm?1. 相似文献
8.
《Ceramics International》2017,43(2):1716-1721
Perovskite-type structured solid electrolytes with the general formula (Li0.25La0.25)1−xM0.5xNbO3 (M=Sr, Ba, Ca, x=0.125) have been prepared by solid-state reaction. Their crystal structure and ionic conductivity were examined by means of X-ray diffraction analysis (XRD), scanning electron microscope (SEM), and alternating current (AC) impedance technique. All sintered compounds are isostructural with the parent compound Li0.5La0.5Nb2O6. Some impurity phase is detected at the grain boundary in the Ba- and Ca-substituted compounds. The substitution of partial Li+ by alkaline earth metal ions has responsibility for the cell volume expansion as determined by the XRD data. The densification is accelerated, with the overall porosity and grain boundary minimized as Sr2+ ions are doped. Among the investigated compounds, the perovskite (Li0.25La0.25)0.875Sr0.0625NbO3 shows a remarkable ionic conductivity of 1.02×10−5 S/cm at room temperature (20 °C) and the lowest activation energy of 0.34 eV in comparison with 0.38 eV and 0.44 eV for the corresponding Ba- and Ca-doped samples, respectively. It is identified that the enhancement of ionic conductivity is attributed to a reduction in activation energy for ionic conduction which is related to an increase in the cell volume. 相似文献
9.
《Journal of the European Ceramic Society》2005,25(4):481-487
The ion conductivities and phase transitions of lanthanum molybdate (La2Mo2O9) substituted with lanthanide rare-earths are investigated using impedance spectroscopy, dilatometry, and X-ray powder diffraction. Among the substituted La2Mo2O9 of 10 mol% Ce, Nd, Sm, Gd, Dy, Er, Yb, the specimens containing Er, and Dy exhibit depressed α–β phase transformation and high conductivities. Their 700 °C conductivities are approximately five to seven times that of La2Mo2O9, around 0.26 S cm−1, comparable with those of (LaSr)(GaMg)O3 and Gd-substituted CeO2. Among the three compositions of 10 mol% Gd, Dy, Er showing depressed phase transition, Er- and Dy-substituted La2Mo2O9 possess relatively low thermal expansion coefficient 11×10−6 K−1, compared with that of the Gd-substituted La2Mo2O9, 18×10−6 K−1, which is near that of La2Mo2O9. Hence, Dy and Er are valuable dopants in improving the La2Mo2O9 properties. Across the lanthanide series, 10 mol%-substituted La2Mo2O9 demonstrates systematic variations in the conductivity–temperature relation. Hysteresis phenomena in both of conductivity and thermal expansion are also observed in those compositions which display phase transition. 相似文献
10.
《Ceramics International》2016,42(10):12156-12160
Li7La3Zr2O12 (LLZO) has cubic garnet type structure and is a promising solid electrolyte for next-generation Li-ion batteries. In this work, Al-doped LLZO was prepared via conventional solid-state reaction. The effects of sintering temperature and Al doping content on the structure and Li-ion conductivity of LLZO were investigated. The phase composition of the products was confirmed to be cubic LLZO via XRD. The morphology and chemical composition of calcined powders were investigated with SEM, EDS, and TEM. The Li-ion conductivity was measured by AC impedance. The results indicated the optimum sintering temperature range is 800–950 °C, the appropriate molar ratio of LiOH·H2O, La(OH)3, ZrO2 and Al2O3 is 7.7:3:2:(0.2–0.4), and the Li-ion conductivity of LLZO sintered at 900 °C with 0.3 mol of Al-doped was 2.11×10−4 S cm−1 at 25 °C. 相似文献
11.
《Journal of the European Ceramic Society》2017,37(2):477-484
SiC-Zr2CN composites were fabricated from β-SiC and ZrN powders with 2 vol% equimolar Y2O3-Sc2O3 additives via conventional hot pressing at 2000 °C for 3 h in a nitrogen atmosphere. The electrical and thermal properties of the SiC-Zr2CN composites were investigated as a function of initial ZrN content. Relative densities above 98% were obtained for all samples. The electrical conductivity of Zr2CN composites increased continuously from 3.8 × 103 (Ωm)−1 to 2.3 × 105 (Ωm)−1 with increasing ZrN content from 0 to 35 vol%. In contrast, the thermal conductivity of the composites decreased from 200 W/mK to 81 W/mK with increasing ZrN content from 0 to 35 vol%. Typical electrical and thermal conductivity values of the SiC-Zr2CN composites fabricated from a SiC-10 vol% ZrN mixture were 2.6 × 104 (Ωm)−1 and 168 W/m K, respectively. 相似文献
12.
《Ceramics International》2015,41(7):8562-8567
The effect of calcination on Li ion conductivity of Li1.5Al0.5Ge1.5(PO4)3 (LAGP) solid electrolyte prepared by a sol–gel method is examined. The Li ion conductivity of LAGP increases with calcination temperature. After reaching maximum conductivity at 850 °C, the conductivity decreases with increase of the calcination temperature. The calcination holding time also strongly affects Li ion conductivity of LAGP. The conductivity increases with holding time until 12 h and then decreases. It is found that the control of crystallization rate is critical to obtain bulk LAGP with high Li ion conductivity. The highest bulk and total conductivities at 30 °C are 9.5×10−4 and 1.8×10−4 S cm−1, respectively, obtained for the bulk LAGP calcined at 850 °C for 12 h. 相似文献
13.
《Journal of the European Ceramic Society》2005,25(4):455-462
Na3Si2Zr1.88Y0.12PO11.94 was for the first time synthesised using mechanically activated mixtures of (ZrO2)0.97(Y2O3)0.03, Na3PO4·12H2O and SiO2 aiming to lower the sintering temperature thus improving chemical homogeneity. The best result was obtained with powder mixtures activated in Teflon containers with partial amorphisation of the reactants attained after milling for 70 h at a maximum of 300 rpm, without significant contamination. The microstructure consists of 300–500 nm agglomerates of smaller grains with size in the range 50–100 nm. Dense, single phase ceramics with submicrometric grain size were obtained from the activated mixture after sintering at 1050 °C for 10 h. The ionic conductivity of these ceramics is 2.5×10−3 S cm−1 at room temperature, and 0.24 S cm−1 at 300 °C. These values are higher than those obtained with non-activated solid state reaction samples and amongst the highest reported in the literature. 相似文献
14.
《Ceramics International》2016,42(3):4361-4369
We study the thermal, mechanical and electrical properties of B4C, BCN, ZrBC and ZrBCN ceramics prepared in the form of thin films by magnetron sputtering. We focus on the effect of Zrx(B4C)1−x sputter target composition, the N2+Ar discharge gas mixture composition, the deposition temperature and the annealing temperature after the deposition. The thermal properties of interest include thermal conductivity (observed in the range 1.3–7.3 W m−1 K−1), heat capacity (0.37–1.6×103 J kg−1 K−1 or 1.9–4.1×106 Jm−3 K−1), thermal effusivity (1.6–4.5×103 J m−2 s−1/2 K−1) and thermal diffusivity (0.38–2.6×10−6 m2 s−1). We discuss the relationships between materials composition, preparation conditions, structure, thermal properties, temperature dependence of the thermal properties and other (mechanical and electrical) properties. We find that the materials structure (amorphous×crystalline hexagonal ZrB2-like×nanocrystalline cubic ZrN-like), more than the composition, is the crucial factor determining the thermal conductivity and other properties. The results are particularly important for the design of future ceramic materials combining tailored thermal properties, mechanical properties, electrical conductivity and oxidation resistance. 相似文献
15.
《Ceramics International》2017,43(4):3847-3853
La9.33Si2Ge4O26 materials have been fabricated from La2O3, SiO2 and GeO2 powders by high speed mechanical alloying followed by conventional and microwave hybrid sintering at different temperatures and holding times. XRD data showed that the apatite phase is formed after 1 h of mechanical alloying at 850 rpm. This phase remained stable after conventional sintering in an electric furnace with density increasing as sintering temperatures and holding times were increased. However, the highest density was achieved for samples sintered in the microwave furnace (5.44 g cm−3), corresponding to a relative density of 98%. The electrical conductivity of the samples microwave sintered at 700 and 800 ºC are 4.72×10−3 and 1.93×10−2 S.cm−1, respectively, with a correspondent activation energy of 0.952 eV. 相似文献
16.
《Journal of the European Ceramic Society》2017,37(8):2871-2876
Pure pyrochlore Lanthanum zirconate (LZ) was synthesized by co-ions complexation method (CCM) at 1300 °C, which is 300 °C lower than that by solid-state method (SSM). At 1450 °C, the LZ prepared by CCM possessed lower thermal conductivity (1.15 W/m K) than that obtained by SSM (1.99 W/m K). This significant decrease may be caused by the different grain size, which is 300 nm and 2.5 μm synthesized by CCM and SSM, respectively. LZ precursor was belt-shaped and the belt shorten and the grain grown with the temperature increasing. Fourier transform infrared spectroscopy suggested the solidification in CCM forms from the complexation between La3+, Zr4+ and CH3COO−, which is the key for solidification. Compared to SSM, CCM is a lower temperature and simpler technology to synthesize nano-size LZ and other rare-earth oxides. 相似文献
17.
《Journal of the European Ceramic Society》2007,27(6):2445-2454
The solubility of Ti4+ in the lattice of apatite-type La9.83Si6−xTixO26.75 corresponds to approximately 28% of the Si-site density. The conductivity of La9.83Si6−xTixO26.75 (x = 1–2) is predominantly oxygen-ionic and independent of the oxygen partial pressure in the p(O2) range from 10−20 to 0.3 atm. The electron transference numbers determined by the modified faradaic efficiency technique are lower than 0.006 at 900–950 °C in air. The open-circuit voltage of oxygen concentration cells with Ti-doped silicate electrolytes is close to the theoretical Nernst value both under oxygen/air and air/10%H2–90%N2 gradients at 700–950 °C, suggesting the stabilization of Ti4+ in the apatite structure. Titanium addition in La9.83Si6−xTixO26.75 (x = 1–2) leads to decreasing ionic conductivity and increasing activation energies from 93 to 137 kJ/mol, and enhanced degradation in reducing atmospheres due to SiO volatilization. At p(O2) = 10−20 atm and 1223 K, the conductivity decrease after 100 h was about 5% for x = 1 and 17% for x = 2. The solubility of Zr4+ in the La9.83Si6−xZrxO26.75 system was found to be negligible, while the maximum concentration of Ce4+ in La9.4−xCexSi6O27−δ is approximately 5% with respect to the number of lanthanum sites. 相似文献
18.
《Journal of the European Ceramic Society》2005,25(6):943-948
The stability of the La3.5Ru4O13 and La2RuO5 compounds in the La–Ru–O system in various atmospheres and various temperature ranges was investigated by thermal analysis, X-ray diffraction analysis and electron microscopy. The La3.5Ru4O13 compound is stable in oxidizing and neutral atmospheres (N2 with 10 ppm O2), while La2RuO5 is partially reduced in a neutral atmosphere to form La2RuO4.6. In a reducing atmosphere both compounds decompose into metallic Ru and La2O3. The thermal expansion coefficients of La2RuO5 and La3.5Ru4O13 at 800 °C are 11.2 × 10−6 K−1 and 9.3 × 10−6 K−1, respectively. The specific electrical resistivity for La3.5Ru4O13 is relatively independent of temperature and is 2 × 10−2 Ω cm at 800 °C, while for La2RuO5 it decreases with increasing temperature and is 1 Ω cm at 800 °C. 相似文献
19.
《Journal of the European Ceramic Society》2014,34(8):1981-1988
La1−x−yCexYbyNbO4 specimens with various Ce and Yb contents were prepared by solid reactions, and their crystal structure, element valence, sinterability and conductivity were investigated. LaNbO4-type single phase was formed at 1200 °C in air, and the lattice of La1−x−yCexYbyNbO4 was distorted from that of LaNbO4 to various extents, depending on the added amount of Ce and Yb. Both La and Nb remained the same valence as they are in LaNbO4; Ce4+, Ce3+ and Yb3+ were detected at room temperature. Highly densified La1−x−yCexYbyNbO4 specimens were achieved by sintering at above 1215 °C in air with conductivity 1–2 orders higher than that of pure LaNbO4 in dry air, wet air and wet 5% H2–N2 atmospheres. The conductivity changed with testing atmosphere owing to the competition of electron and proton conduction, and maximal value 4.7 × 10−4 S cm−1 was obtained in wet air at 900 °C. 相似文献
20.
Ag enhanced electrochemical performance for Na2Li2Ti6O14 anode in rechargeable lithium-ion batteries
《Ceramics International》2016,42(6):6874-6882
Due to the characteristics of an electronic insulator, Na2Li2Ti6O14 always suffers from low electronic conductivity as anode material for lithium storage. Via Ag coating, Na2Li2Ti6O14@Ag is fabricated, which has higher electronic conductivity than bare Na2Li2Ti6O14. Enhancing the Ag coating content from 0.0 to 10.0 wt%, the surface of Na2Li2Ti6O14 is gradually deposited by Ag nanoparticles. At 6.0 wt%, a continuous Ag conductive layer is formed on Na2Li2Ti6O14. While, particle growth and aggregation take place when the Ag coating content reaches 10.0 wt%. As a result, Na2Li2Ti6O14@6.0 wt% Ag displays better cycle and rate properties than other samples. It can deliver a lithium storage capacity of 131.4 mAh g−1 at 100 mA g−1, 124.9 mAh g−1 at 150 mA g−1, 119.1 mAh g−1 at 200 mA g−1, 115.8 mAh g−1 at 250 mA g−1, 111.9 mAh g−1 at 300 mA g−1 and 109.4 mAh g−1 at 350 mA g−1, respectively. 相似文献