Polyaniline (PANI)–molybdenum trisulfide (MoS3) electrode, prepared by a multi-step procedure, and polyaniline electrode were characterized in non-aqueous electrolyte (0.5 M LiClO4/acetonitrile) by cyclic voltammetry, electrochemical impedance spectroscopy and the electrochemical quartz crystal microbalance (EQCM). The voltammetric charge decreased slightly (20%) upon incorporation of MoS3 in the PANI film electrode. The normalized low frequency capacitance defined as the low frequency capacitance/voltammetric charge ratio is identical for both PANI and PANI–MoS3 electrodes suggesting that MoS3 does not contribute to the capacitance measured. The EQCM data is consistent with mixed transport of anions and cations. Upon oxidation in 0.5 M LiClO4/acetonitrile, a mass change of 43 g/mol is observed for PANI–MoS3 and this suggests that solvent is also involved in addition to ClO4 − ingress and Li+ expulsion.