We have developed a novel nanocomposite material, [PANI]0.24MoO3, comprised of poly(aniline) chains interleaved with the layers of MoO3, using concomitant ion exchange−polymerization in the presence of an external oxidizing agent. The characterization of this material using SEM, FTIR spectroscopy, powder XRD, and thermal analysis shows that the poly(aniline) is present primarily in the emeraldine salt form. The high degree of ordering evident from the oriented film XRD patterns suggests that the PANI chains are at least partially aligned in the ac (basal) plane. The properties of the polymer nanocomposite for electrochemical lithium insertion were compared to those of the alkali molybdenum oxide using the materials as cathodes in conventional lithium cells. The polymer/oxide battery demonstrated substantially reduced cell polarization on galvanostatic cycling, compared to the alkali molybdenum oxide in the absence of PANI. The resultant enhanced ion and/or electron transport induced by incorporation of the polymer, in addition to the redox capacity of the intercalated PANI, provided a moderate increase in cell capacity and improved the reversibility of the Li insertion reaction.