Polyaniline (PANI) is electrochemically synthesized using agar gel as a template (Agar-PANI). The material characteristics and electrochemical behavior of the Agar-PANIs are compared with those of polyaniline synthesized by means of conventional methods (C-PANI). The electrochemical synthesis is monitored using the cyclic potential sweep (CPS) technique. The dependency of the total deposition charge on the number of cycles can be satisfactorily explained with a CPS parameter, n, and is consistent with scanning electron micrographs. The electrical conductivity and the bulk density of the Agar-PANI samples are 1.5 S cm(-1) and 1.53 g cm(-3), which are three orders and four times larger than those of the C-PANI samples, respectively. On the other hand, C-PANI and Agar-PANI have similar crystallinity. The capacitances of the Agar-PANIs are 200-500 F cm(-3) at 5 mHz and these electrodes would be adequate for high energy density devices. The accommodation of glutamate is 1.5 x 10(-3) mol cm(-3) for the Agar-PANI, which is two orders of magnitude larger than when a polypyrrole electrode is used. (C) 2003 Elsevier B.V All rights reserved.