Abstract:
As "Necessity is the mother of invention", energy is stored from primary sources and
released out, for consumption when there is a shortage of energy, to balance the life of
human beings. In the modern world, sensational research has been done to design storage
devices. While considering cost and environmental aspects, the researcher is impatient to
find a friendlier environment and portable energy storage devices. The desire for
environment-friendly and portable energy storage devices has steered the thorough
investigation for all-solid-state rechargeable batteries.
Solid state batteries have got attention because of more energy security and long life.
Phosphate-based ceramic electrolytes are promising candidates for solid state electrolyte-
based lithium and sodium-ion batteries. Sodium-ion batteries can potentially hold energy
comparable to that of commercial lithium-ion batteries. Li resources are limited whereas
sodium is one of the most abundant elements in the Earth’s crust. Rechargeable sodium
cells are the ideal alternative to lithium-ion batteries based on material abundance and
standard electrode potential.
In this work, phosphate-based solid state electrolytes as M1+xAlxTi2-x (PO4)3 where M=
Li, Na, and x = 0.5, are synthesized by solid state reaction and ball milling method. The
main objective of this study is to examine the ionic behavior, homogeneity, porosity, crystal
structure, and band-gap and also to determine the charging and discharging rate of the
prepared material. The crystal structure of synthesized powder is examined by the x-rays
diffraction technique. X pert high score software is used to determine the phase of the
prepared material. Synthesized material has a single crystalline phase same as NASICON
type material with space group R3̅c. Microstructure analysis is done by using scanning
electron microscopy. The porosity of solid-state electrolytes is determined by the
Archimedes method. The charging and discharging rate are examined by electrochemical
techniques (AC-impendence-conductivity, cyclic voltammetry). The ionic conductivities
of both have the same exponential value with 2.09×10-3 and 1.96×10-3 at 25°C, respectively.
Ultraviolet spectroscopy is done to examine the band-gap. Tauc plot is used to determine
band-gap for Li1.5Al0.5Ti1.5 (PO4)3 and the Na1.5Al0.5Ti1.5 (PO4)3. Raman spectroscopy is
used to determine the vibrational energy modes of the prepared material
