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

Abstract

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.