Self-charging supercapacitor power cell (SCSPC) received much attention for harvesting and storing energy in an integrated device, which paves the way for developing maintenance free autonomous power systems for various electronic devices. In this work, a new type of SCSPC device is fabricated comprising 2D molybdenum di-selenide (MoSe2) as an energy storing electrode with polyvinylidene fluoride-co-hexafluoropropylene/tetraethylammonium tetrafluoroborate (PVDF-co-HFP/TEABF4) ion gelled polyvinylidene fluoride/sodium niobate (PVDF/NaNbO3) as the piezopolymer electrolyte. The fabricated SCSPC delivers a specific capacitance of 18.93 mF cm−2 with a specific energy of 37.90 mJ cm−2 at a specific power density of 268.91 µW cm−2 obtained at a constant discharge current of 0.5 mA. The MoSe2 SCSPC device can be self-charged with the aid of mechanical deformation induced using the applied compressive force, thus making it harvest and store energy. The MoSe2 SCSPC device can be charged up to a maximum of 708 mV under a compressive force of 30 N in 100 s, and the mechanism of charge-storage is discussed in detail. The experimental findings of this work demonstrate the high efficiency of the fabricated MoSe2 SCSPC device, which can provide new insights for developing sustainable power sources for the next generation wearable electronic applications.