Lithium-ion conductive glass-ceramics with composition ratio control and their electrochemical characteristics

Abstract

We have developed the high ionic conducting glass-ceramics with the crystalline phase of Li 1+x+y Al x (Ti 2¹y Ge y )P 3¹z Si z O 12 with the NASICON type structure. This type of glass-ceramics exhibits high lithium-ion conductivity of 10 ¹4 S cm ¹1 or more at room temperature. Although this glass-ceramics reacts with Li metal gradually with the passage of time, we have improved the thermal and electrochemical properties by controlling constitution of Ti and Ge in the Li-ion conducting glass-ceramics with the NASICON type structure. Those glass-ceramics worked well as electrolyte of a lithium-ion secondary battery by the charge discharge test using a half cell with LiFePO 4 cathode at room temperature.

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

“…This homogeneity is comparable to that obtained by the wet-chemical methods of synthesis. Furthermore, complex compositions and controllable microstructure can be achieved utilizing scalable techniques. , Ionic conductivities comparable or even better than those related to materials obtained by solid-state and chemical synthesis methods have been reported. ,,− Therefore, the following topic will discuss the main advances of lithium ion NASICON prepared as glass-ceramics. The influence of the NASICON composition on conductivity, as well as the parameters used for glass crystallization and the resulting microstructure, will also be widely discussed.…”

“…However, cationic transport is usually limited in these materials. − Sulfide glasses present the best transport properties, showing typical lithium conductivity on the order of 10 –3 S cm –1 at room temperature . However, they are very unstable in environmental conditions, generating H 2 S by humidity exposure. , Oxide electrolytes are superior in chemical stability, ion selectivity, and thermal stability compared to polymers and sulfides. ,, In particular, the Na + Super Ionic Conductor (NASICON) is a class of phosphate-type electrolytes that can approach lithium conductivity in the same order of sulfides (10 –4 to 10 –3 S cm –1 ), ,,− while the chemical stability in air is maintained. ,, …”

“…This structure provides many possibilities for an A-mobile cation other than sodium (Li + , Ag + , K + , Cu + , etc. ), , which is conducted through structural channels in all three dimensions. , The variety and proportion of B (III) cations (e.g., Al 3+ , Cr 3+ , Fe 3+ , In 3+ ) and B (IV) cations (e.g., Zr 4+ , Ge 4+ , Hf 4+ , Sn 4+ ) change the net polarizability and lattice parameters and allows an extra quantity of mobile A (I) cation in the skeletal structure. , These conditions highly impact the cationic motion and conductivity by consequence, varying in a broad interval (on the order of 10 –8 to 10 –3 S cm –1 at room temperature). ,,− ,, …”

VanadiumK-edge XANES in vanadium-bearing model compounds: a full multiple scattering study

“…Vanadium is a transition metal that can occur in nature in a variety of oxidation states (from 0 to 5+) and coordination geometries, with tetrahedral, square pyramidal and octahedral being the most common (Schindler et al, 2000). The V structural role is widely studied both in crystalline structures and in glasses, because V-bearing compounds and alloys find several applications in the steel industry, for catalysis (Hä vecker et al, 2002;Surnev et al, 2003;Safonova et al, 2009;Walter et al, 2010) and as materials for cathodes in Li-ion batteries (Sakurai & Yamaki, 1988;Katoh et al, 2010;Moretti et al, 2013). V-bearing glasses have been largely studied in the past 40 years because of their conductivity properties (Munakata, 1960;Mott, 1968;Sayer et al, 1971;Frazier & France, 1977;Giuli et al, 2004;Seshasayee & Muruganandam, 1998;McGreevy, 2001;Ori et al, 2011;Schuch et al, 2012).…”

Application of LiCoPO4 Positive Electrode Material in All-Solid-State Lithium-Ion Battery

“…A composite electrode was prepared from suspensions containing 30 wt% active material, 30 wt% LATP electrolyte, 30 wt% AB, and 10 wt% polytetrafluoroethylene. The LATP powder was synthesized by glass-ceramics process described by Katoh et al, 14 which was also used for preparing an electrolyte plate as separator. The sintering of the LiCoPO 4 -LATP composite electrode and LATP electrolyte plate was performed at 800°C for 5 min in the form of disks (outside diameter, 15 mm) under an applied pressure of 90 MPa by using SPS-515S (Sumitomo Coal Mining).…”