Iwuoha Emmanuel I.Njomo Njagi2025-07-012025-07-012024N/Ahttps://hdl.handle.net/10566/20560To meet a fast-growing market demand for next generation portable electronic devices with higher performance and increased device functionalities, efficient electrical energy devices with substantially higher energy, power densities and faster recharge times such as supercapacitors are needed. The overall aim of this thesis was to synthesize nanostmctured su lphonated polyaniline and transition metal single, binary and ternary mixed oxide doped nanocomposites with electro-conductive properties. These nanocomposites were anchored on activated graphitic carbon and used in design of asymmetric supercapacitors. Tan talum(IV)oxide, tantalum(IV)oxide-n ickel (II)oxide, tantalum(ll)oxide- manganese(IIT)oxide, tantalum(II)oxide-nickel(II)oxidemanganese( l l,IIl)oxide nanoparticles were synthesised using modified sol-gel methods. These were then dispersed, individually, in acidic media through sonication and incorporated in-situ into the polymeric matrix during the oxidative chemical polymerization of aniline doped with poly(4-styrene sulphonic acid). These novel polymeric nanocomposites were characterised with FTIR, UV-visible, TEM, SEM, EDS, XRD to ascertain successful polymerization, doping, morphology and entrapment of the metal oxide nanoparticles. SECM approach curves and interrogation of CV revealed that these nanocomposites are conductive and electro-active.enSol gel methodTransition mixed metal oxides nanopartic lesSulphonated po lyanil ine nanocompositesElectrochemical cellElectrochemical double layer capacitorThesis