A new design for dry polyaniline rechargeable batteries

Polyanilline powder of high conductivity is prepared by chemical polymerization of aniline in a solution of 0.10 M aniline, 2 M perchloric acid and 0.15 M ammonium persulfate at 5 °C. The powder is mixed with graphite and acetylene black to obtain the required conductivity and porosity. The mixed powder is compressed into a ring shape at a pressure of 2 t cm−2 for use as positive electrodes (cathodes) in batteries. Zinc powder is mixed with magnesium oxide, zinc oxide and sodium carboxymethyl cellulose (CMC), and then compressed into a cylindrical shape at a pressure of 7 t cm−2 for use as negative electrodes (anodes) in batteries. The battery electrolyte comprises 2 M Zn(ClO4)2, 1 M NH4ClO4, and 1.0×10−4 M Triton-X100 at pH 3. A 1 wt.% Optalloy powder is added to the negative-electrode composite to prevent the release of hydrogen gas. The assembled battery has an open-circuit voltage (OCV) of 1.64 V, a charge storage capacity of 125.43 m Ah g−1, and a Coulombic efficiency greater than 95% during the first 100 charge–discharge cycles. Due to the low amount of electrolyte used, the battery is considered as a dry battery.