<p>The intercalated clay incorporated graphite composite electrodes will receive an unprecedented attention, as it reveals new composite engineering perspectives. In that sense, a graphite composite electrode is fabricated using cerium intercalated montmorillonite clay (Ce-MMT), obtaining a graphite-(Ce-MMT) composite electrode (G-(Ce-MMT)CE) that exhibits an improved electrochemical performance due to synergetic electrode matrix, in which cerium(IV) ions serve as a supportive electroactive mediator. G-(Ce-MMT)CE analyte response exhibits an ideal cyclic voltammogram signal while resulting in a high sensitivity towards complex inorganic anions than simple cations even though both have similar redox centre, exhibiting ~ 2.0&#xa0;A m mol⁻¹ sensitivity towards Fe(CN)₆]⁴⁻/[Fe(CN)₆]³⁻ over Fe²⁺/Fe³⁺ that is ~ 0.55&#xa0;A m mol⁻¹. The polyaniline nanofibers with villi-like surface projections dominantly materialize on G-(Ce-MMT)CE surface during aniline electropolymerization under Ce⁴⁺ intervention, resulting in an interwoven PANI network with low charge transfer (4.1&#xa0;Ω) and serial resistance (17.8&#xa0;Ω). The polyaniline-coated G-(Ce-MMT)CE is a potential candidate for supercapacitors, as it attributes to a specific capacitance above 1300&#xa0;F g⁻¹ while delivering a high energy and power density, which is evident from both cyclic voltammetry and galvanostatic charge–discharge analysis. The pseudocapacitor-like behaviour is dominant with a supercapacitor cell that consists of two identical polyaniline-G-(Ce-MMT)CE segments, as it also accounts for a high coulombic efficiency that indicates a better cyclic stability, ensuring a longer lifespan.</p> Graphical abstract <p></p>