Non-precious electrocatalysts with high activity and low cost are desirable candidates for many state-of-the renewable energy devices, such as energy storage and conversion. However, the design and formation of such materials remain a significant challenge. In this study, a facile soft-templated route is designed for the synthesis of mesoporous graphitic carbon nitride (meso g-C₃N₄) and cobalt modified g-C₃N₄ composites. Once the meso g-C₃N₄ modified with cobalt (Co) source, the morphology slowly changed to aggregated nanoballs like morphology at a particular Co composition (3 wt.%). The mesoporous architecture and morphology were confirmed by using N₂-sorption and high resolution transmission electron microscopy studies, respectively. The effects of Co concentration on the nanostructures and electrochemical performances of the composites for supercapacitor application are investigated. The obtained mesoporous Co/g-C₃N₄ nanoballs showed excellent electrochemical performance related to high specific capacitance, good rate capability, and greater cyclic stability than other samples (mesoporous g-C₃N₄ nanoflakes and non-porous analogue). The exceptional electrochemical performance of mesoporous Co/g-C₃N₄ nanoballs for supercapacitor could be attributed to an effective integration of g-C₃N₄ nanoflakes and cobalt that maximizes the synergistic interaction between them. Detailed synthetic procedure and electrochemical properties of these nanostructures will be discussed in the meeting with reference to the physicochemical properties.