Methods for Lithium Ion NASICON Preparation: From Solid-State Synthesis to Highly Conductive Glass-Ceramics

Abstract

Lithium ion-containing Na + Super Ionic Conductor (NASICON) electrolytes are important materials for new energystorage technologies. The NASICON abbreviation represents several compounds with similar structures applied as solid electrolytes, including those conductors of lithium ions. Different methods have been used to synthesize these materials, as well as innumerous other methods used to form the electrolyte in its final shape. The synthesis methods and processing techniques significantly affect the microstructure and conductivity of the electrolyte as a result. Therefore, this paper provides an overview of the main synthesis methods and processing techniques applied for lithium ion NASICON production. First, a general view of the NASICON structure and the variety of possible compositions will be discussed. Next, the influence of the synthesis methods (e.g., solid-state reaction, sol−gel, polymeric precursor, sol−gel/ electrospinning) and sintering techniques (e.g., conventional, microwave, and Spark Plasma Sintering) will be presented. A special topic will be devoted for glass-ceramics production and evaluation, based on their advantageous ionic conductivity and potentiality for practical use on a large-scale. Moreover, the current results for electrochemical cells simulating the application of these materials in batteries will be presented. Finally, a general point of view of the authors about the future for NASICON electrolytes will be provided, presenting oncoming trends for research.

Melamine-Regulated Ceramic/Polymer Electrolyte Interface Promotes High Stability in Lithium-Metal Battery

“…An in-depth research has been done on the usage of ceramic solid-state electrolytes, one of which is the Na superionic conductor (NASICON)-type Li-ion conductor Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (LAGP). LAGP shows exceptional air stability, a high Li + transference number, and ionic conductivity of up to 10 –4 S cm –1 at room temperature. , This material also allows large-scale synthesis and is suitable for commercialization. However, the contact between the electrode and LAGP presents a challenge to the general use of these materials .…”

The fabrication of a highly conductive ceria-embedded gadolinium-stabilized bismuth oxide nanocomposite solid electrolyte for low-temperature solid oxide fuel cells

“…Activation energy is calculated on the assumption that ionic conduction in a solid electrolyte is a thermally stimulated process. In other words, according to an Arrhenius-type equation, the conductivity of an electrolyte tends to increase with an increase in temperature, as follows: 43 where σ o is a pre-exponential factor, E a is the activation energy, T is the absolute temperature, and k is the Boltzmann constant.…”

“…This approach is preferred because it prevents electrode polarization and allows for the differentiation of grain and grain-boundary contributions to the total resistance, among other benefits. 43 The intercept of the semicircle with the real axis in the low frequency domain was used to determine the bulk resistance at all concentrations, as shown in Fig. 4.…”

Combined wet milling and heat treatment in water vapor for producing amorphous to crystalline ultrafine Li1.3Al0.3Ti1.7(PO4)3 solid electrolyte particles

“…Certain oxide-type SEs need to be crystallized because of their low ionic conductivity in the amorphous state. [15][16][17][18] Further, their increased surface area results in the strong adsorption of milling solvents at the particle surface aer milling. Heat treatment at high temperatures for crystallization or removal of the adsorbed materials causes Li evaporation and a side reaction with the active materials within the composites to form a reactive layer.…”