The Polymer Society of Korea

Ampasala Surya Kiran (Sungkyunkwan University)

엄숭호 (Sungkyunkwan University)

This work presents the design and energineering of electrochemical performance of a hierarchical MnO₂@C@NiSe₂ core–shell electrode for supercapacitor applications. The architecture integrates birnessite δ-MnO₂ as the active shell with a conductive carbon interlayer and a stable NiSe₂ core, enabling improved charge transport and ion diffusion. Structural optimization enhances electrochemical behavior, resulting in high capacity and good cycling stability. An asymmetric supercapacitor device assembled using the optimized electrode exhibits high specific capacitance with excellent energy and power density in an aqueous KOH electrolyte. In addition, a pouch-type device demonstrates practical feasibility in by delivering a stable 3 V output capable of powering electronic displays and LED arrays. These results highlight the advantages of hierarchical core–shell design and demonstrate the potential of MnO₂@C@NiSe₂ hybrid electrodes for advanced energy storage systems.