Solid Electrolyte

The emerging development of electronic and electric vehicle demand safer battery technology. Recently, the Lithium Ion Battery is a promising energy storage technology due to the higher capacity and higher energy density. Briefly, Lithium ion battery consist of electrode, separator and electrolyte. High electronic conductivity is required from electrode material while high ionic conductivity is expected from the electrolyte. Current commercial lithium-ion battery use LiPF₆ and separator to facilitate the lithium ion transport during charge-discharge process. However, the relatively flammable electrolyte and a low-melting point separator may cause some problems sucha as explosion. Therefore, to improve the battery safety, solid electrolyte is developed.

The replacement of liquid electrolyte with solid-electrolyte is proposed accordingly. The Li₃PO₄ which has a total conductivity with a value of 7 x 10^-8 S/cm. However, the ideal ionic conductivity of electrolyte is 10^-3 S/cm. The Li₃PO₄ have been prepared by two different methods which are wet chemical and solid-state reaction. Eventhough The Li₃PO₄ prepared by solid-state reaction shows the existence of Li₄P₂O₇ as an impurity, it exhibits better conductivity, 3x10^-7 S/cm, compared to that of wet-chemical reaction prepared Li₃PO₄, 4x10^-8 S/cm. It shows that the Li₄P₂O₇ on the sample may have a positive impact on its electrochemical properties. Moreover, a Li₃PO₄ composited with montmorillonite-PVDF exhibits higher conductivity compared to that of pure Li₃PO₄. Another candidate for solid electrolyte material is Li₂O – P₂O₅ compound.