Search Results (5)

Lithium lanthanum titanate (LLTO) is a promising solid electrolyte for all-solid-state lithium-ion batteries (ASSLIBs), and its total conductivity is dramatically influenced by the ceramic microstructure. Here we report a novel aerodynamic levitation rapid solidification method to prepare dense LLTO ceramics with a dendrite-like microstructure, which can be hardly obtained by conventional sintering. At optimal nominal lithium content and cooling rate, the solidified LLTO ceramic achieved a high total conductivity of 2.5 × 10⁻⁴ S·cm⁻¹ at room temperature, along with excellent mechanical properties such as a high Young’s modulus of 240 GPa and a high hardness of 16.7 GPa. Results from this work suggest that aerodynamic levitation rapid solidification is an effective processing method to manipulate the microstructure of LLTO ceramics to minimize the GBs’ contribution to the total conductivity, which may be expanded to prepare other oxide-type lithium electrolytes. Full article

Lithium lanthanum titanate (LLTO) is a very promising material due to its ability to conduct lithium ions. It has many potential applications in the field of lithium batteries and sensors. Typical synthesis methods include solid-state reaction and sol–gel synthesis. We report a novel solvothermal synthesis method that produces almost single-phase LLTO samples at significantly reduced costs. The samples thus obtained were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), electrical impedance spectroscopy (EIS), and chemical analysis. The results obtained for the newly synthesized samples were compared with results obtained from samples prepared using the solid-state reaction method. The XRD data show the formation of orthorhombic LLTO for the solvothermal synthesis, tetragonal LLTO for the hydrothermal synthesis, and cubic LLTO for the solid-state reaction. Additionally, XRD showed that the solid-state reaction of LLTO is a multi-stage process in which intermediary compounds such as La₂Ti₂O₇ are formed. The bulk ionic conductivity of the LLTO samples produced through the solvothermal and hydrothermal processes is estimated at 10⁻⁴ S/cm, and the grain boundary conductivity is estimated at 10⁻⁶ S/cm. Full article

The rapid development of portable electronic devices and the efforts to find alternatives to fossil fuels have triggered the rapid development of battery technology. The conventional lithium-ion batteries have reached a high degree of sophistication. However, improvements related to specific capacity, charge rate, safety and sustainability are still required. Solid state batteries try to answer these demands by replacing the organic electrolyte of the standard battery with a solid (crystalline, but also polymer and hybrid) electrolyte. One of the most promising solid electrolytes is Li_3xLa_2/3−xTiO₃ (LLTO). The material nevertheless presents a set of key challenges that must be resolved before it can be used for commercial applications. This review discusses the synthesis methods, the crystallographic and the ionic conduction properties of LLTO and the main limitations encountered through a number of selected studies on this material. Full article

Based on the LiLaTiO₃ compound, a ceramic membrane for a photoelectrochemical cell was created. The microstructure, phase composition, and conductivity of a semiconductor photoelectrode and a ceramic membrane were studied by using various experimental methods of analysis. A ceramic Li conducting membrane that consisted of Li_0.56La_0.33TiO₃ was investigated in solutions with different pH values. The fundamental possibility of creating a photoelectrochemical cell while using this membrane was shown. It was found that the lithium-conductive membrane effectively works in the photoelectrochemical system for hydrogen evolution and showed a good separating ability. When using a ceramic membrane, the pH in the cathode and anode chambers of the cell was stable during 3 months of testing. The complex impedance method was used to study the conductive ceramic membrane in a cell with separated cathode and anode chambers at different pH values of the electrolyte. The ceramic membrane shows promise for use in photoelectrochemical systems, provided that its resistivity is reduced (due to an increase in area and a decrease in thickness). Full article

Lithium ions play a crucial role in the energy storage industry. Finding suitable lithium-ion-conductive membranes is one of the important issues of energy storage studies. Hence, a perovskite-based membrane, Lithium Lanthanum Titanate (LLTO), was innovatively implemented in the presence and absence of solvents to precisely understand the mechanism of lithium ion separation. The ion-selective membrane’s mechanism and the perovskite-based membrane’s efficiency were investigated using Molecular Dynamic (MD) simulation. The results specified that the change in the ambient condition, pH, and temperature led to a shift in LLTO pore sizes. Based on the results, pH plays an undeniable role in facilitating lithium ion transmission through the membrane. It is noticeable that the hydrogen bond interaction between the ions and membrane led to an expanding pore size, from (1.07 Å) to (1.18–1.20 Å), successfully enriching lithium from seawater. However, this value in the absence of the solvent would have been 1.1 Å at 50 °C. It was found that increasing the temperature slightly impacted lithium extraction. The charge analysis exhibited that the trapping energies applied by the membrane to the first three ions (Li⁺, K⁺, and Na⁺) were more than the ions’ hydration energies. Therefore, Li⁺, K⁺, and Na⁺ were fully dehydrated, whereas Mg²⁺ was partially dehydrated and could not pass through the membrane. Evaluating the membrane window diameter, and the combined effect of the three key parameters (barrier energy, hydration energy, and binding energy) illustrates that the required energy to transport Li ions through the membrane is higher than that for other monovalent cations. Full article