Complex Investigation of Water Impact on Li-Ion Conductivity of Li_1.3Al_0.3Ti_1.7(PO₄)₃—Electrochemical, Chemical, Structural, and Morphological Aspects

Abstract

The interest in alternative energy sources grows rapidly and demands improved materials. The cutting-edge investigations focus attention on the development and optimization of solid electrolytes for advanced energy storage. Their chemical and structural stability defines both battery performance and lifetime, yet it is studied poorly even for well-known superionic conductors such as NASICON-based compounds. In this work, we studied the Li1.3Al0.3Ti1.7(PO4)3 (LATP) stability toward water. Corresponding ceramics were synthesized in pellet form through the solid-state reaction and had been immersed in deionized water for different periods of time with subsequent electrochemical (electrochemical impedance spectroscopy), structural (powder X-ray diffraction analysis, Raman spectroscopy, computational modeling), chemical (ceramicsenergy-dispersive X-ray spectroscopy; mother-solutionsinductively coupled plasma mass spectrometry), and morphological (scanning and transmission electron microscopy) analyses. Water exposure triggers drastic conductivity losses (64% for σt) with accompanying lithium elution (exceeds 13 atomic%) and unit cell shrinkage. All these changes reach a plateau after 2 h of water exposure.

A Complex Investigation of LATP Ceramic Stability and LATP+PVDF Composite Membrane Performance: The Effect of Solvent in Tape-Casting Fabrication

“…Since the beginning of our research activities, the path toward the desired lithium-conductive composite membrane has not been easy as we intended to develop the full-cycle synthesis routine. First, we designed the solid-state synthesis of Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 (LATP) ceramic of the pure NASICON-type phase with high IC (above 4 ∙ 10 −4 S cm −1 ) but severe sensitivity to moisture that had never been characterized before [ 31 , 32 , 33 ]. From now on, we additionally expected the introduction of the inert matrix to protect the LATP filler from the ambient humidity and preserve its originally high IC.…”

“…The entire work was categorized into two parts, where a solid instrumental basis was applied to study the materials, including: X-ray diffraction (XRD), attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). Previously, we showed the instability of LATP toward water led to drastic IC losses, along with structural and morphological changes, mostly due to the elution of lithium ions [ 33 ]. The NAq solvents applied in this study possess twice lower polarity compared to water; the dielectric constants are: water 80.1, DMSO 46.7, DMF 36.7, and NMP 32.2 [ 40 ].…”

Synthesis and Characterization of Lithium-Conducting Composite Polymer–Ceramic Membranes for Use in Nonaqueous Redox Flow Batteries

“…We synthesized the composite membranes used in this work by initially refining the procedures for both the ceramic filler and the polymer film. Here, we focus on the preparation of the PVDF film, as we have described the LATP synthesis elsewhere. , The target polymer film should ideally be thin and possess low porosity and uniform roughness. To identify suitable conditions for membrane preparation, we varied the casting conditions as follows: selecting a suitable solvent → achieving a uniform membrane thickness → cleaning the casting substrate → drying the samples → controlling additional minor variations.…”

“…Ceramic pellets of LATP and LAGTP were prepared through a solid-state reaction . Lithium carbonate (Li 2 CO 3 , ≥99%, Sigma-Aldrich), ammonium dihydrogen phosphate (NH 4 H 2 PO 4 , ≥98%, Alfa Aesar), aluminum nitrate (Al­(NO 3 ) 3 ·9H 2 O, ≥97%, RusChem), germanium­(IV) oxide (GeO 2 , ≥99.99%, Sigma-Aldrich), and titanium­(IV) oxide (TiO 2 , ≥99.5%,Sigma-Aldrich) were used for the preparation of LATP and LAGTP powder.…”

Lattice Dynamics in the NASICON NaZr2(PO4)3 Solid Electrolyte from Temperature-Dependent Neutron Diffraction, NMR, and Ab Initio Computational Studies

“…The flexibility of the NASICON structure has also allowed for the development of battery materials containing mobile divalent cations, such as calcium or zinc . Finally, in some recent studies, NASICON compounds have also been examined for applications in unconventional battery architectures, such as seawater or redox-flow batteries …”