The present study involves a new process for preparing the conductive polyaniline; this process is known as absorption polymerization. PAn powders prepared by the absorption polymerization process show higher bulk density, better granularity and film processibility than those made by the traditional chemical oxidation polymerization method. PAn films prepared using the solution-casting technique were used to assemble thin-firm Li/PAn batteries with a modified poly(ethylene oxide) (PEO) electrolyte film. The Li/PAn rechargeable battery shows reasonably high energy density and excellent rechargeability.