Molybdenum selenide nanotubes decorated carbon net for a high performance supercapacitor

A unique encapsulated asymmetric supercapacitor is implemented with a yet unreported electrode architecture of molybdenum selenide nanotubes decorated carbon net (MoSe2@CN) hybrid. MoSe2 and CN are independently synthesized hydrothermally by using SiO2 nanospheres as a scaffold and a template respectively. The synergistic effects of MoSe2, namely, a porous nanostructured morphology that enables easy electrolyte penetration, and maximizes active MoSe2 sites’ utilization coupled with a high redox activity towards Li-ion insertion and extraction via short ion-diffusion pathways and of CN, such as high electrical conductivity that ensures facile ion and electron transport across the electrodes, and a distinctive holey nanostructure result in a superior areal specific capacitance (SC) of 101.3 mF cm−2 (at 5 mV s−1)/88 mF cm−2 (at 0.5 mA cm−2) for the asymmetric MoSe2@CN//CN cell contrasting strongly against the lower performances of the symmetric MoSe2, CN and MoSe2@CN analogues. The MoSe2:CN proportion in the MoSe2@CN hybrid is found to be optimal at 3:1, for the cell based on this hybrid delivers significantly enhanced SCs compared to its’ counterparts with lower (1:1 and 2:1) and higher (4:1) MoSe2 content. The MoSe2@CN//CN cell also outperforms many reported MoS2/carbon nanomaterial composites in terms of the voltammetric and galvanostatic SCs. Further, an energy density of 12.22 µWh cm−2 at a power density of 0.25 mW cm−2 is achieved for the asymmetric MoSe2@CN//CN cell. The demonstration of a mini toy fan using three such cells connected in series validate the practical usability of this cell