Facile synthesis of synergetic MoO₂/MoS₂@GO nanohybrid as energy-efficient electrode material for high-performance asymmetric supercapacitor applications

Rechargeable batteries and supercapacitors have been unitized extensively for energy storage applications, but each possesses its downsides, such as gradual charge transfer and low energy density, respectively. Hybrid supercapacitors are gaining extreme consideration due to their versatility in merging both power density and energy storage performance to an optimum level. Still, increasing energy and power density requires significant attention for their utilization in industrial applications. For this purpose, a prospective MoO2/MoS2@GO ternary nanohybrid is synthesized by employing a wet-chemical-aided approach and used as a synergistic electrode for high-performance asymmetric supercapacitor applications. FESEM images revealed that the enriched active sites, provided by highly porous shape, MoS2-covered MoO2 nanoparticles interconnected with large area GO sheets facilitate quicker ions transport along with an exceptional surface area. From half-cell measurements, the integrated electrode displayed a high specific capacitance of 1530 F/g at a current density of 2 A/g. For practical applications, an asymmetric device (ASC) device MoO2/MoS2@GO||AC||KOH was assembled which displayed the specific energy and specific power of 76 Wh/kg and 825 W/kg, respectively, in conjunction with excellent capacitance retention of 91.3 % after 10,000 continuous cycles. The theoretical Dunn model was used to validate experimental findings by quantitatively analyzing the maximum diffusive and capacitive contribution of 78 % (10 mV/s) and 72 % (100 mV/s) to overall ASC device capacity, respectively. These fascinating results show that graphene-hybridized metal oxide/sulfide composites could potentially be a great choice for high-performance energy and power applications in industrial, biomedical, and sensing technologies.