We fabricated a hybrid power source device with three electrodes of which one was a LiPF6-doped polyaniline (PAn) electrode playing the roles of both the positive electrode of a lithium secondary battery and an electrode of a redox supercapacitor. As a consequence, the shared electrode acts as a positive electrode or a positive terminal of a hybrid power source. The negative terminal was connected between a lithium metal electrode and another LiPF6-doped PAn electrode. After characterizing and comparing this hybrid power source with a single lithium secondary battery, its discharge performance was superior to that of a single lithium secondary battery when adopting the sheet-type PAn-LiPF6 electrodes and the porous separator as an electrolyte medium. In this case, the hybrid power source was shown to be advantageous in the high pulse mode of discharge. (c) 2006 Elsevier B.V All rights reserved.