Synthesis and characterisation of new nanocomposites of poly(3-decylpyrrole) (P3DP) and poly(hexadecylpyrrole) (P3HDP) with V2O5 are described. These nanocomposites were characterised using X-ray diffraction (XRD), electrochemical quartz crystal microbalance, electroacoustic impedance (EAI) and cyclic voltammetry. The results were compared with an other nanocomposite, polypyrrole (Ppy)V2O5, aiming to verify the influence of the side chains of P3DP and P3HDP on the electrochemical behaviour Of V2O5. These hybrid materials have different structures that modify the electrochemical properties. The side chains of P3DP and P3HDP contributed to greater electrochemical stability than that of Ppy into the V2O5 matrix. This results in a higher specific capacity for the P3DP/V2O5 and P3HDP/V2O5 nanocomposites (115 and 106 Ah kg(-1), respectively) than that of Ppy/V2O5 (50 Ah kg(-1)) after 50 electrochemical cycles.