The improvement in the discharge characteristics
can be attributed to the larger surface area of sol gel prepared cathode
with desired stoichiometry. The cells have not been subjected to
charge–discharge cycles due to lowvalue of Na+ diffusion coefficient of
about 10−12 cm2/s when compared to that of value 10−8 cm2/s for Li+
in the LiCoO2 based systems [17] and low ionic conductivity of the
electrolyte (10−6 S/cm) when compared to that of conventional liquid
electrolyte.