Role of the electrode-edge in optically sensitive three-dimensional carbon foam-MoS₂ based high-performance micro-supercapacitors

Developing high-performance micro-supercapacitors in a limited footprint area is important for miniaturized electronics, where enhancement in energy storage per unit area is critical. In this study, we used zig-zag edge based interdigitated electrodes for the micro-supercapacitor. The novel electrode geometry contributes to improved electrochemical capacitance, energy density, and power density compared to planar edge interdigitated electrodes. The zig-zag edges of the electrodes induce stronger electric field intensity between the interdigitated fingers contributing to enhanced charge storage capacity. A simulation study further confirmed the enhanced electric field intensity. A layered molybdenum disulfide (MoS₂) nanostructure directly grown on a three-dimensional scaffold of carbon foam (CF) is used as the electrode material. The novel zig-zag interdigitated electrode geometry demonstrated an areal capacitance of 21 mF cm⁻², which is 242% (or ∼350% enhancement while considering electrode interdigitated finger area only) higher than that of the planar edge electrodes using the same material. Moreover, the optically sensitive CF-MoS material resulted in an optically chargeable supercapacitor upon illumination with 600 nm radiation, where a self-powered voltage generation is observed. The study provides broad future prospects for combining electrode design and optically sensitive materials for enhanced charge storage in micro-supercapacitors. Thus, the study demonstrated a promising route to design efficient planar supercapacitor devices for miniaturized electronics and self-powered devices.