Polyaniline composite designed for solid polymer electrolyte

Improved ionic conductivity of solid polymer electrolytes (SPE) was achieved by adding polyaniline (PANI) in membrane formulation. SPE composite membranes contain: tris(4-hidroxybutylacrylate)-phosphate, polyphosphoester, lithium salts and small amount of PANI. The conductivity of membranes increases with PANI content and above a certain amount it decreases. The variation of the conductivity vs temperature is linear, characteristic for a thermally activated process. The activation energy for polymer matrix without PANI is 0.30 eV and 0.26 eV for polymer matrix with PANI. Conductivity enhancement in the composite polymer matrix is caused by the presence of PANI due to the increase in the concentration of free ions. PANI decreases the salt aggregation and as a consequence, the concentration of free ions was increased by improving dispersion of the lithium salt in membranes.