This study dives into the successful synthesis of CeO2/CuFe2O4 nanocomposites using the auto-combustion approach and elucidates their characteristics. The electrochemical analysis of samples calcination produced at 700 °C (CeO2/CuFe2O4) revealed good results, with a specific capacitance (Cs) of 123 F/g at a current density (CD) of 0.25 A g−1 in a 1 M KOH solution. Significantly, these findings emphasize the established technique's potential for producing new, highly active, flexible, and environmentally friendly substrate materials appropriate for a variety of applications in supercapacitors. CeO2/CuFe2O4 nanocomposites may be useful in biological and medicinal research. Despite their extensive use, little study has been conducted to investigate their possible impact on cell viability, in normal cell lines. The positive benefits of the CeO2/CuFe2O4 nanocomposite structure were assessed using X-ray diffraction (XRD). To assess the impact of these nanocomposites, MTT cytotoxicity tests were performed on normal (mouse muscle fibroblast - BLO-11) cell lines. The results show that CeO2/CuFe2O4 nanocomposites have a high potential for biomedical applications, as they had no harmful effects on the cell types evaluated. As a result, the structure of the material appears to be crucial in determining both electrochemical performance and cell longevity. This discovery is significant because it provides useful insights into the morphological engineering of electrodes for a variety of applications and influences future material development.