Sol-gel synthesis of Li1.3Al0.3Ti1.7(PO4)3 solid electrolyte

A modified sol-gel process was studied as applied to synthesize a lithium-conducting solid electrolyte of composition Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP) using water-soluble salts Al(NO₃)₃ · 9H₂O, LiNO₃ · 3H₂O, and (NH₄)₂HPO₄ and a titanium(IV) citrate complex. As-synthesized samples were characterized using X-ray powder diffraction, DSC/TG, SEM, and impedance spectroscopy. Sintering of as-synthesized amorphous powders at 700°C was found to yield LATP with crystallite sizes of 42–48 nm. Ionic conductivity of the electrolyte measured in the frequency range 25–10⁶ Hz in disks having 86–90% density that were sintered at 1000°C was (3–4) × 10^?4 S/cm. Temperature-dependent ionic conductivity was studied in the range 25–200°C. The activation energy of conduction was determined for LATP.     

Li1.3Al0.3Ti1.7(PO4)3 filler effect on (PEO)LiClO4 solid polymer electrolyte

Composite polymer electrolyte (CPE) films consisting of PEO, LiClO₄, and Li_1.3Al_0.3Ti_1.7(PO₄)₃ with fixed EO/Li = 8 but different relative compositions of the two lithium salts were prepared by the solution casting method. The CPE films were characterized using SEM, DSC, electrical impedance spectroscopy (EIS), and ion transference number measurement. It was found that the incorporation of LiClO₄ and Li_1.3Al_0.3Ti_1.7(PO₄)₃ into PEO by keeping EO/Li = 8 reduced the crystallinity of PEO from 50.34% to the range of 3.57–15.63% depending upon the relative composition of the two salts. The room temperature impedance spectra of the CPE films all exhibited a shape of depressed semicircle in the high frequency range and inclined line in the low frequency range, but the high temperature ones were mainly inclined lines. The Li⁺ ionic conductivity of the CPE films mildly increased and then decreased with increasing Li_1.3Al_0.3Ti_1.7(PO₄)₃ content, and the maximum conductivities were obtained at Li_1.3Al_0.3Ti_1.7(PO₄)₃ content of 15 wt % for all measuring temperatures, for example, 1.378 × 10^?3 S/cm at 100 °C and 1.387 × 10^?5 S/cm at 25 °C. The temperature dependence of the ionic conductivity of the CPE films follows the Vogel–Tamman–Fulcher (VTF) equation The pseudo activation energies (E_a) were rather low, 0.053–0.062 eV, indicating an easy migration of Li⁺ in the amorphous phase dominant PEO. The pre‐exponent constant A and ion transference number t_Li+ were found to have a similar variation tendency with increasing Li_1.3Al_0.3Ti_1.7(PO₄)₃ content and reached their maximums also at Li_1.3Al_0.3Ti_1.7(PO₄)₃ content of 15 wt %. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 743–751, 2005     

Water-stable high lithium-ion conducting Li1.4Al0.4Ge0.2Ti1.4(PO4)3-TiO2-LiCl•H2O–epoxy resin composite film with high mechanical strength as separator for Li-air batteries

Journal of Solid State Electrochemistry - Aqueous rechargeable lithium-air batteries are candidates for next-generation high energy and power density batteries. The key material of this type...     

PEO与Li1.3Al0.3Ti1.7(PO4)3络合的离子导体聚合物电解质

将实验室经固相反应的精细Li1．3Al0．3Ti1．7(PO4)3盐与聚氧化乙烯(PEO)按照不同，nEO／nLi摩尔比，通过溶液浇铸法制备了固态聚合物电解质。红外光谱分析表明Li1．3Al0．3Ti1．7(PO4)3盐与PEO之间有络合产生。SEM照片显示PEO晶体外层为无定形相所包覆形成的胞状结构。经电化学阻抗(简称EIS)法测试发现聚合物电解质膜的室温阻抗谱图是由高频处一压缩的半圆和低频下一条直线组成，而高温时的阻抗谱主要为一条直线。离子电导率的测试结果得到：当nEO／nLi=16时，聚合物电解质室温下电导率约为10^-6／cm，343K时达到10^-4s／cm。离子迁移率的数据表明聚合物电解质为离子和电子共混的导体，但在聚合物电解质体系中电荷的迁移主要是由离子作为载流子导电造成的，由测试结果可得此电解质为离子导体。     

Double NASICON-type cell: ordered Nd3+ distribution in Li0.2Nd0.8/3Zr2(PO4)3

The NASICON compound Li(0.2)Nd(0.8/3)Zr(2)(PO(4))(3), synthesized by a sol-gel process, has been structurally characterized by TEM and powder diffraction (neutron and X-ray). It crystallizes in the space group R3[combining macron] (No. 148): at room temperature, the Nd(3+) ions present an ordered distribution in the [Zr(2)(PO(4))(3)](-) network which leads to a doubling of the classical c parameter (a = 8.7160(3) A, c = 46.105(1) A). Above 600 degrees C, Nd(3+) diffusion occurs leading at 1000 degrees C to the loss of the supercell. This reversible cationic diffusion in a preserved 3D [Zr(2)(PO(4))(3)](-) network is followed through thermal X-ray diffraction. Ionic conductivity measurements have been undertaken by impedance spectroscopy, while some results concerning the sintering of the NASICON compound are given.     

Li1.3Ti1.7Al0.3(PO4)3与Na+的离子交换

锂离子传导材料Li_1.3Ti_1.7Al_0.3(PO₄)₃是具有NASICON结构的功能材料, 与Na⁺进行离子交换具有选择性高的特性. 研究了在不同温度条件下NaCl和LiCl水溶液中Li_1.3Ti_1.7Al_0.3(PO₄)₃上的Na/Li离子交换行为. 实验结果表明, 升高温度能显著提高Li_1.3Ti_1.7Al_0.3(PO₄)₃的Na/Li交换反应速率, 提高LiCl中杂质Na的分离效果.     

LiSn2(PO4)3-based polymer-in-ceramic composite electrolyte with high ionic conductivity for all-solid-state lithium batteries

Journal of Solid State Electrochemistry - In this work, fabrication and electrochemical behavior of polymer-in-ceramic composite electrolytes based on lithium-ion conducting triclinic LiSn2(PO4)3...     

Boron group element doping of Li1.5Al0.5Ge1.5(PO4)3 based on microwave sintering

Journal of Solid State Electrochemistry - We report effectiveness of dopants selected from group 13, such as B, Ga, and In, on the conductivity of Li1.5Al0.5Ge1.5(PO4)3 (LAGP) that is recognized as...     

Li metal-free rechargeable all-solid-state Li2S/Si battery based on Li7P3S11 electrolyte

Journal of Solid State Electrochemistry - As high energy density and enhanced safety are required for the lithium-ion battery development, all-solid-state battery has attracted significant...     

Ti4+离子掺杂对Li3V2(PO4)3晶体结构与性能的影响

采用溶胶凝胶/碳热还原法合成了锂离子电池正极材料Li3V2(PO4)3及其掺Ti化合物Li3-2x(V1-xTix)2-(PO4)3. 电化学测试结果表明, 经Ti4+离子掺杂后材料的充放电性能及循环性能明显提高. 与纯相Li3V2(PO4)3在3.58、3.67和4.08 V出现三个平台相比, 掺杂后材料的前两个平台发生简并且平台趋于模糊的倾斜状态. 这种趋势随掺杂量的增大而增强. 差热分析(DTA)表明掺杂生成了稳定的酌相产物. 采用X射线衍射和Rietveld方法表征了化合物的晶体结构, 结果表明, 三个不同位置Li的不完全占据导致晶体中产生阳离子空穴, 使材料在常温下的离子电导率提高了3个数量级. 锂离子混排提高了样品的电导率和充放电比容量.     

Silane-modified Li6.4La3Zr1.4Ta0.6O12 in thermoplastic polyurethane-based polymer electrolyte for all-solid-state lithium battery

Journal of Solid State Electrochemistry - The ceramic/polymer composite solid electrolyte prepared by a simple physical mixing method has the problem of packing agglomeration and uneven dispersion,...     

Li2Mg2Si4O10F2、H2Mn8O16·1.4H2O和Li1.3Ti1.7Al0.3(PO4)3在高浓度LiCl水溶液中的离子交换行为

研究了用功能材料 Li2Mg2Si4O10F2(LHT)、 H2Mn8O16@ 1.4H2O(CRYMO)和 Li1.3Ti1.7Al0.3(PO4)3(LTAP)分别去除高浓度氯化锂水溶液中的杂质 Fe3+、 K+和 Na+ .实验结果表明,这几种功能材料分别对溶液中的杂质 Fe3+、 K+和 Na+有很高的选择性,除杂效果明显 .分析和研究了这几种功能材料在高浓度氯化锂水溶液中分别与 Fe3+、 K+和 Na+的交换行为 .结果表明,在高浓度氯化锂溶液中这几种功能材料与杂质交换的动力学行为可近似用 JMAK方程描述.     

Carbon coated nano-LiTi2(PO4)3 electrodes for non-aqueous hybrid supercapacitors

The Pechini type polymerizable complex decomposition method is employed to prepare LiTi(2)(PO(4))(3) at 1000 °C in air. High energy ball milling followed by carbon coating by the glucose-method yielded C-coated nano-LiTi(2)(PO(4))(3) (LTP) with a crystallite size of 80(±5) nm. The phase is characterized by X-ray diffraction, Rietveld refinement, thermogravimetry, SEM, HR-TEM and Raman spectra. Lithium cycling properties of LTP show that 1.75 moles of Li (~121 mA h g(-1) at 15 mA g(-1) current) per formula unit can be reversibly cycled between 2 and 3.4 V vs. Li with 83% capacity retention after 70 cycles. Cyclic voltammograms (CV) reveal the two-phase reaction mechanism during Li insertion/extraction. A hybrid electrochemical supercapacitor (HEC) with LTP as negative electrode and activated carbon (AC) as positive electrode in non-aqueous electrolyte is studied by CV at various scan rates and by galvanostatic cycling at various current rates up to 1000 cycles in the range 0-3 V. Results show that the HEC delivers a maximum energy density of 14 W h kg(-1) and a power density of 180 W kg(-1).     

Li2Mg2Si4O10F2、H2Mn8O16•1.4H2O和Li1.3Ti1.7Al0.3(PO4)3在高浓度LiCl水溶液中的离子交换行为

研究了用功能材料Li2Mg2Si4O10F2 (LHT)、H2Mn8O16•1.4H2O (CRYMO)和Li1.3Ti1.7Al0.3(PO4)3 (LTAP)分别去除高浓度氯化锂水溶液中的杂质Fe3＋、K＋和Na＋.实验结果表明，这几种功能材料分别对溶液中的杂质Fe3＋、K＋和Na＋有很高的选择性，除杂效果明显.分析和研究了这几种功能材料在高浓度氯化锂水溶液中分别与Fe3＋、K＋和Na＋的交换行为.结果表明，在高浓度氯化锂溶液中这几种功能材料与杂质交换的动力学行为可近似用JMAK方程描述.     

Development of high ionic-conductive Li1.5Al0.5Ge1.5(PO4)3 glass-ceramic solid electrolyte sheet at low temperature using glass/powder composite

Journal of Solid State Electrochemistry - Because of some drawbacks of the organic electrolytes, such as high toxicity and flammability, inorganic electrolytes have attracted attention regarding...     

Li3Al(MoO4)3, a lyonsite molybdate

Trilithium aluminium trimolybdate(VI), Li₃Al(MoO₄)₃, has been grown as single crystals from α‐Al₂O₃ and MoO₃ in an Li₂MoO₄ flux at 998 K. This compound is an example of the well known lyonsite structure type, the general formula of which can be written as A₁₆B₁₂O₄₈. Because this structure can accomodate cationic mixing as well as cationic vacancies, a wide range of chemical compositions can adopt this structure type. This has led to instances in the literature where membership in the lyonsite family has been overlooked when assigning the structure type to novel compounds. In the title compound, there are two octahedral sites with substitutional disorder between Li⁺ and Al³⁺, as well as a trigonal prismatic site fully occupied by Li⁺. The (Li,Al)O₆ octahedra and LiO₆ trigonal prisms are linked to form hexagonal tunnels along the [100] axis. These polyhedra are connected by isolated MoO₄ tetrahedra. Infinite chains of face‐sharing (Li,Al)O₆ octahedra extend through the centers of the tunnels. A mixed Li/Al site, an Li, an Mo, and two O atoms are located on mirror planes.     

Effect of Al2O3 -coating on the electrochemical performances of Li3V2(PO4)3/C cathode material

The effect of Al₂O₃ -coating on Li₃V₂(PO₄)₃/C cathode material for lithium-ion batteries has been investigated. The crystalline structure and morphology of the synthesized powders have been characterized by XRD, SEM, and HRTEM, and their electrochemical performances are evaluated by CV, EIS, and galvanostatic charge/discharge tests. It is found that Al₂O₃ -coating modification stabilizes the structure of the cathode material, decreases the polarization of electrode and suppresses the rise of the surface film resistance. Electrochemical tests indicate that cycling performance and rate capability of Al₂O₃-coated Li₃V₂(PO₄)₃/C are enhanced, especially at high rates. The Al₂O₃-coated material delivers discharge capacity of 123.03 mAh g^?1 at 4 C rate, and the capacity retention of 94.15 % is obtained after 5 cycles. The results indicate that Al₂O₃ -coating should be an effective way to improve the comprehensive properties of the cathode materials for lithium-ion batteries.     

Complex Phosphates in the Li(Na)3]PO4-InPO4 Systems

Subsolidus sections in the systems Li₃PO₄-InPO₄ (950°C) and Na₃PO₄-InPO₄ (800, 900, and 1000°C) have been studied by X-ray powder diffraction. The compound Li₃In(PO₄)₂ has been synthesized, and the nasicon-type solid solution Li_{3(1 ? x)}In_{2 + x}(PO₄)₃ (0.67 ≤ x ≤ 0.80). has been found to exist. In the system Na₃PO₄-InPO₄, the solid solution Na_{3(1 ? x)}In_x/3PO₄ (0 ≤ x ≤ 0.2) and two complex phosphates exist: Na₃In(PO₄)₂ and Na₃In₂(PO₄)₃. These complex phosphates are dimorphic, with the irreversible-transition temperature equal to 675 and 820°C, respectively. Na₃In(PO₄)₂ degrades at 920°C. Ionic conductivity has been measured in some phases in the system.     

Changes in electronic structure upon Li insertion reaction of monoclinic Li3Fe2(PO4)3

The electrochemical lithium insertion reaction of monoclinic Li(3)Fe(2)(PO(4))(3) as cathode materials of lithium-ion batteries was investigated from the viewpoint of the electronic structure around Fe and the polyanion unit (PO(4)). Fe K-edge and L(III,II)-edge XAS measurements revealed that Fe(3+) was reduced to Fe(2+) upon Li insertion. In addition, O K-edge and P K-edge XAS also showed spectral changes upon Li insertion, which corresponded to changes in the electronic structure of the PO(4) polyanion unit. The ab initio density functional calculation was performed within the GGA and LDA+U methods. The LDA+U method reproduced well the cell potential upon lithium intercalation into Li(3)Fe(2)(PO(4))(3), whereas the GGA method underestimated the intercalation. The calculated electronic structure of Li(3)Fe(2)(PO(4))(3) described strong P 3p-O 2p covalent bonding, while weak hybridization was indicated in Fe 3d-O 2p. Moreover, the difference in electronic density between Li(3)Fe(2)(PO(4))(3) and the lithiated model indicated that the polarization effect between inserted Li and oxygen induced the changes in the electronic structure around the polyanion unit.