Abstract Cobalt oxide (Co 3 O 4 ) is recognized as a promising electrode material for supercapacitors due to its high theoretical capacitance, significant redox activity, cost‐effectiveness, and eco‐friendliness. However, its practical use is limited by challenges such as poor electrical conductivity, low power density, and structural instability. Recent developments have aimed at improving its electrochemical performance through a variety of approaches. These include creating binary and ternary metal oxide composites, doping with heteroatoms, and adding carbon‐based materials to enhance conductivity and structural stability. The use of conductive polymers and metal nanoparticles has also bolstered charge transport and overall stability. Advances in morphology engineering, such as the creation of hierarchical structures, binder‐free electrodes, and combinations of multiphase oxides, have led to improved specific capacitance, cycling longevity, and rate performance. Additionally, optimizing electrolytes, especially with redox‐active additives and hybrid types, has significantly improved both energy and power densities. Advanced synthesis techniques, such as hydrothermal processing, electrodeposition, and chemical bath deposition, enable fine control over nanostructures and phases, resulting in enhanced performance. This review critically analyses the synergistic impact of material composition, nanostructure design, synthesis technique, and electrolyte engineering, offering insights into the rational development of next‐generation Co 3 O 4 ‐based supercapacitor electrodes.
Shinde et al. (2025) studied this question.