A solid state battery based on polyaniline (PANI), Zinc (Zn) and a gel polymer electrolyte (GPE) is reported for the first time. Poly (ethylene oxide)–zinc sulphate-nanoclay-H2O based GPE was used as the separator. The GPEs with a varying composition of salt were evaluated for their electrochemical performance. The highest conductivity at ambient temperature for the GPEs was found to be 5.54 × 10−4 S cm−1. Cyclic voltammetry and impedance studies, with the Zn/GPE/Zn cell, showed reversibility with respect to Zn/Zn2+ couple. The battery showed a capacity of 43.9 Ah kg−1 of PANI and a coulombic efficiency higher than 100%. However, a decrease in capacity was observed for the system during the cycling.