Two CeO2/carbon nanotube composites were prepared in both basic and neutral medium thus using different deposition procedures of the cerium oxide. The modification of the synthesis conditions varied the hydrolysis rate of the cerium oxide precursor, leading to materials with different morphology, texture and surface chemistry, significantly changing their electrochemical performance. The different mechanisms of charge storage occurring on the surface of the materials were thoroughly studied to investigate the origin of the observed changes in the electrochemical properties. To that end, a combination of sweep wave voltammetry and deconvolution analysis in acid (1M H2SO4), basic (1M NaOH) and neutral (1M Na2SO4) electrolytes was conducted. The faradaic activity of the composite prepared by slow hydrolysis (containing well-dispersed and small ceria particles) is enhanced as compared with the composite prepared by fast hydrolysis, which originates bulky particles. Display omitted •Fine identification of charge storage mechanisms in EDCL electrodes.•Unravelling the pseudofaradaic activity of CeO2/carbon nanotube composite.•Different active phases were identified as function of the used electrolyte.•Potential application for the characterization of a wide variety of electrodes.