A Review on Anode Side Interface Stability Micromechanisms and Engineering for Garnet Electrolyte-based Solid-state Batteries

Li-ion solid electrolytes, which are compatible with metallic lithium anodes, are the key component of all solid-state batteries. Recently, the garnet Li₇La₃Zr₂O₁₂ solid electrolyte has experienced booming development and shown great potential for its excellent overall performance. However, further understanding of its stability with lithium is required for a longer battery lifetime. In this review, latest research work on the interface between garnet-type solid electrolytes and lithium is presented, including both mechanisms governing interface stability and interface engineering methods. The development prospects and potential directions for following research are also discussed in the last section.     

Ta 5+掺杂Li7La3Zr2O12的合成及其性能研究

本文采用固相法制备了Ta ⁵⁺掺杂的石榴石型无机固体电解质Li_7-xLa₃Zr_2-xO₁₂（xTa-LLZO）,研究了不同的掺杂量对材料性能的影响. 通过X射线发射光谱（XRD）、冷场发射电子扫描电镜（FESEM）和电化学阻抗（EIS）对材料进行物理表征和阻抗测试,并且组装LiFePO₄//LLZTO//Li全固态锂电池测试电池的循环稳定性. 结果表明,随着Ta ⁵⁺掺杂的增加,材料呈现出一个单一的立方相结构,当Ta ⁵⁺掺杂量为14.09wt.%（即x=0.3）时,材料的室温离子电导率达到最大（2.58×10 ^-4 S·cm ^-1）,呈现出稳定的立方相结构且具有相对较高的致密度（89.16%）,并具有较稳定的循环稳定性,经过50个循环后容量保持率依然保持到88.67%左右.     

Synthesis,Characterization and Luminescent Properties of La2Zr2O7:Eu3+ Nanorods

The Eu³⁺-doped La₂Zr₂O₇ phosphor with rod-like morphology was successfully synthesized by conventional solid state reaction and hydrothermal method. X-ray diffraction patterns, transmission electron microscopy, and photoluminescence spectra were employed to charac-terize its structure and morphology as well as luminescent properties. The results indicated that the red-emitting phosphor La₂Zr₂O₇:Eu³⁺ had well crystallized and belonged to the cubic structure with space group of Fd3m. The as-obtained product mainly appeared as straight nanorods with an average diameter of 47 nm and length of 50-700 nm. The pos-sible growth mechanism was also discussed. It was found that under blue excitation with a wavelength of 466 nm, the La₂Zr₂O₇:Eu³⁺ phosphor exhibited a characteristic red emission at 616 nm that was attributed to the hypersensitive ⁵DO_→⁷F2 _{electric dipole transition of Eu³⁺ ions. Meanwhile, it was more interesting to note that the emission of ⁵D}1_→⁷FJ _{(J=0, 1, 2) transitions and the splitting patterns of ⁵D}0_→⁷FJ _{(J=1, 2, 4) transitions of Eu³⁺ ions can be observed in the luminescent spectra of La2Zr2O7:Eu³⁺. It was demonstrated that Eu³⁺ preferred to occupy a low symmetry site.}     

La2Zr2O7催化剂结构相变对甲烷氧化偶联反应性能的影响

采用共沉淀法并通过改变焙烧温度制备了一系列具有不同晶相结构的La₂Zr₂O₇催化剂，在微型固定床反应器上评价其甲烷氧化偶联反应性能，并利用XRD、Raman、CO₂-TPD、XPS等表征手段，探究催化剂的物相结构、表面碱性以及表面氧物种的变化规律。结果表明，随着焙烧温度从700℃逐渐升高到1200℃，La₂Zr₂O₇催化剂结晶度不断提高，晶相发生明显变化，从无定形结构逐渐向缺陷萤石结构过渡，最终转变成烧绿石结构。焙烧温度提高促使La₂Zr₂O₇晶相转变过程中，催化剂表面的碱性强度减弱，中等碱性位数量以及具有催化活性的表面氧物种O₂^2-和O₂^-的相对含量不断减少，致使催化剂的CH₄转化率和C₂₊选择性不断降低。其中，无定形LZO-CP-700催化剂表现出最佳的甲烷氧化偶联反应性能。     

Comparative Study of CuO Species on CuO/Al2O3, CuO/CeO-Al2O3 andCuO/La2O-Al2O3 Catalysts for CO Oxidation

CuO/Al2O3, CuO/CeO2-Al2O3, and CuO/La2O3-Al2O3 (denoted as Cu/Al, Cu/CeAl, and Cu/LaAl) catalysts were prepared by an impregnation method. CuO species and CuO/Al2O3 thermal solid-solid interaction were characterized by in situ XRD, Raman spectroscopy and H2-TPR techniques. For the Cu/Al catalyst, a CuAl2O4 phase exists between the CuO and Al2O3 layer and the CuO phase exists on the surface in both highly dispersed and bulk forms. For the Cu/CeAl catalyst, there is highly dispersed and bulk CuO on the surface, but most of the CuO has transferred into the internal layer of CeO2 as bulk CuO and CuAl2O4. For the Cu/LaAl catalyst, only bulk CuO is present on the surface of the catalyst and no CuAl2O4 is formed. The catalytic activity order for CO oxidation is Cu/CeAl>Cu/Al>Cu/LaAl. The highly dispersed CuO on the catalyst surface may be the active phase for CO oxidation. The results show that the addition of CeO2 not only promotes both the transference of CuO and the formation of CuAl2O4 but also favors the CO oxidation due to the association of highly dispersed CuO with CeO2, while La2O3 hinders the transference of CuO and the formation of CuAl2O4.     

Effect of Calcination Temperature on La-Modified Al2O3 Catalysts for Vapor Phase Hydrofluorination of Acetylene to Vinyl Fluoride

A La-modified Al₂O₃ catalyst was prepared with deposition-precipitation method. The effect of calcination temperature on the reactivity for vapor phase hydrofluorination of acetylene to vinyl fluoride. The catalysts calcined at different temperatures were characterized using NH₃-TPD, pyridine-FTIR, X-ray diffraction, and Raman techniques. It was found that the calcination process could not only change the structure of these catalysts but also modify the amount of surface acidity on the catalysts. The catalyst calcined at 400 oC exhibited the highest conversion of acetylene (94.6%) and highest selectivity to vinyl fluoride (83.4%) and lower coke deposition selectivity (0.72%). The highest activity was related to the largest amount of surface acidity on the catalyst, and the coke deposition was also related to the total amount of surface acidic sites.     

La2O3助剂对Au/TiO2催化氧化CO性能的影响

采用溶胶-凝胶法制备了TiO2以及La2O3-TiO2载体, 再用沉积沉淀法制备Au/TiO2和Au/La2O3-TiO2催化剂, 并对催化剂的CO氧化反应活性进行测试. 结果表明, La2O3助剂可以显著提高催化剂催化氧化CO的活性. X射线衍射(XRD)、程序升温脱附(TPD)、N2吸附-脱附(BET)表征结果表明, La2O3助剂不仅提高了催化剂比表面积, 抑制了TiO2晶粒尺寸的长大, 并且增强了TiO2的晶格应变, 在O2气氛吸附过程中主要在TiO2表面形成O-物种. 原位傅立叶变换红外(FT-IR)结果进一步表明, La的掺杂不仅提高了吸附在Au活性位CO的氧化速率, 还使TiO2表面形成第二种活性位, 从而显著提高了催化活性.     

Recycling in telomerization of butadiene with D‐xylose: Pd(TPPTS)n‐KF/Al2O3 as an active catalyst

A palladium‐TPPTS catalyst heterogenized on KF/alumina has been shown to be effective and recyclable for the selective formation of monooctadienylxylopyranosides via the telomerization of butadiene with D ‐xylose. Copyright © 2007 John Wiley & Sons, Ltd.     

Solid state synthesis of lithiated manganese oxides from mechanically activated Li2CO3–Mn3O4 mixtures

The solid state formation of lithium manganese oxides has been studied from the thermal decomposition of mixtures Li₂CO₃–Mn₃O₄ with X_Li (lithium cationic fraction)=0.33 (LiMn₂O₄), 0.50 (LiMnO₂) and 0.66 (Li₂MnO₃). The analysis of the reactivity has been performed mainly by thermoanalytical (TG/DSC) and diffractometric (XRPD) techniques either on physical mixtures and on mixtures subjected to mechanical activation by high energy milling. At X_Li=0.33, the cubic lithium manganese spinel oxide (LiMn₂O₄) forms in air. TG measurements showed that the reaction starts at a considerably lower temperature in the activated mixture. By variable temperature X-ray diffraction it has been assessed that, upon mechanical activation, LiMn₂O₄ forms directly and its formation is completed within 700 °C whereas, starting from a physical mixture, the formation goes through Mn₂O₃ and is complete only at 800 °C. At T>820 °C LiMn₂O₄ reversibly decomposes to LiMnO₂ and Mn₃O₄ with an enthalpy of 30.05 kJ mol⁻¹ of LiMn₂O₄. At X_Li=0.50, by annealing under nitrogen flow for 6 h at 650 °C the activated mixture, the orthorhombic LiMnO₂ is formed. Such a formation goes through a mixture of LiMnO₂ and LiMn₂O₄. The enthalpy of LiMnO₂ solid state formation from the activated mixture has been determined to be 57.4 kJ mol⁻¹ of LiMnO₂. At X_Li=0.66 in air the mechanical activation considerably lowers the temperature within the monoclinic phase Li₂MnO₃ forms. Besides the reaction enthalpy could be determined as 40.13 kJ mol⁻¹ of Li₂MnO₃. The reaction, when performed under nitrogen flow, goes through the formation of LiMnO₂. Such a first stage of the reaction is affected by the temperature of reaction rather than by mechanical activation. The activation greatly enhances the second stage of the reaction leading from LiMnO₂ to Li₂MnO₃.     

可见光下Fe3+掺杂对K2La2Ti3O10分解水制氢性能的影响

采用溶胶-凝胶法制备了Fe3+掺杂的Fe-K2La2Ti3O10光催化剂, 并通过X射线衍射(XRD)、紫外-可见漫反射(DRS)、X射线光电子能谱(XPS)等技术对其进行了表征和分析, 考察了不同掺杂量对K2La2Ti3O10的性质及光催化分解水制氢活性的影响. 结果表明, Fe-K2La2Ti3O10在400-650 nm范围内显示强吸收, 光谱响应扩展到可见光区(λ>400 nm), 掺杂Fe3+后, K2La2Ti3O10的可见光区的光催化制氢活性显著提高, 掺杂量为nFe/nTi=0.04时活性最佳, 当催化剂用量为0.1 g, 反应液为CH3OH(30 mL)+H2O(90 mL)时, 产氢量达到1.92 μmol·h-1, 为未掺杂时的4倍.     

Solvation Effect of Li+ on the Voltammetric Properties of [PMo12O40]3−. Part 2: Comparative Studies on the Preferential Solvation in Acetonitrile+S and Acetone+S Mixtures

For [PMo₁₂O₄₀]^3?, the presence of Li⁺ produced a two‐electron wave at nearly the same potential as the first one‐electron wave in acetonitrile or acetone. The voltammetric behavior of [PMo₁₂O₄₀]^3? in a binary mixture of acetonitrile and solvent S was compared with those in a mixture of acetone and S. When the donor number (DN) of S>20, the first two‐electron wave was converted into one‐electron waves in such binary mixtures. The conversion occurred at lower mole fractions of S in an acetonitrile+S mixture than in an acetone+S mixture. The ⁷Li NMR results showed that the preferential solvating ability of Li⁺ with S was greater in the former mixture. A linear relationship was found between the iso‐solvation point x_iso(S) and the reciprocal of the difference between the DNs of S and acetonitrile, which gave the basis to explain the anomalies observed for a mixture of acetonitrile and H₂O.     

Pt含量及活化温度对固体超强酸催化剂异构化性能的影响

本文制备了固体超强酸Pt- S2O82-/ZrO2-Al2O3催化剂,采用XRD、TPR、TG-DTA 、FT-IR等表征手段对催化剂进行了表征,并在高压微反－色谱联合装置上,考察了Pt质量分数和活化温度对催化剂正戊烷异构化性能的影响. 结果表明,Pt能使催化剂的还原温度降低;增强载体表面氢气的溢流效应,提高酸强度;Pt质量分数0.10%、活化温度300℃的催化剂异构化活性最高,在反应温度220℃、压力2.0MPa、氢烃摩尔比4:1、质量空速1.0h-1时,异戊烷产率达62.3%. 在100h内异戊烷收率可稳定在55%左右,选择性在98.0％以上.     

硬脂酸法制备SO42-/Fe2O3-SiO2固体酸及其催化性能的初步探讨

首次用硬脂法制备了Fe2O3-SiO2混合氧化物,经浸渍H2SO4后再焙烧得SO4^2-/Fe2O3-SiO2固体酸催化剂。用TEM,XRD,N2吸附/脱附和TG-DTA等手段对其进行了表征,结果显示制得的Fe2O3-SiO2混合氧化物具有多孔结构,且随着Si含量的增大,其比表面积明显增大,但孔径减小。用乙酸/丁醇酯化催化反应评估了该固体酸的催化性能。