Fabrication of CeO2/PANI composites for high energy density supercapacitors

Highlights: • Fabrication of CeO₂/PANI composite was successfully prepared using easy solution mixing method. • Combinational approaches of rare earth oxides with conducting polymer composites posses' excellent pseudocapacitive nature. • Superior specific capacitance, rate capacitance and cyclic stability. • Outstanding performance of asymmetric and symmetric devices. - Abstract: Combinational approaches of rare earth oxides with conducting polymer composites have gained vast attention in supercapacitor field due to the outstanding pseudocapacitive property. Here we detail the redox reaction based on CeO₂/polyaniline nanostructure to grasp the superior electrochemical nature of the composite. The CeO₂/polymer nanostructure showed the improved specific capacitance of 1452 F g⁻¹ at 2 A g⁻¹ when compared to pristine CeO₂ (927 F g⁻¹ at 2 A g⁻¹). The composite also maintains excellent rate capacitance (875 F g⁻¹ at 10 A g⁻¹) and good cyclic stability upto 1500 cycles at high current density of 20 A g⁻¹. Symmetric and asymmetric supercapacitor devices were fabricated using CeO₂/ PANI as an electrode. Moreover, the asymmetric supercapacitor possesses excellent specific capacity (256 F g⁻¹ at 2 mV s⁻¹) with high energy density (75 Whkg⁻¹) and high power density (566 Wkg⁻¹). These results suggest a potential usefulness of CeO₂/ PANI composite exploit as an efficient electrode for supercapacitor applications.