Nano-flowering ternary molybdenum disulfide/polypyrrole/manganese dioxide composite to boost electrochemical performance for its solid-state supercapacitors

Flexible supercapacitors face limitations in capacitance and energy density due to structural constraints and sluggish ion diffusion. Herein, a cost-effective two-step confined synthesis is proposed to prepare molybdenum disulfide (MoS 2 )/polypyrrole (PPy)/manganese dioxide (MnO 2 ) ternary composites with high energy storage performance. The plane structure of MoS 2 not only ameliorates bipolaron concentration of PPy, but also preserves its conjugated structure during the combination with MnO 2 , thereby enhancing electrochemical stability. Nanoflower-structured MnO 2 can effectively improve ions adsorption/transport, as well as reinforce electrochemical reactivity. The measured specific surface areas increase from 33.25 m 2 /g for PPy to 112.47 m 2 /g for MoS 2 /PPy/MnO 2 . Consequently, synergistic effect of MoS 2 /PPy/MnO 2 components delivers a higher specific capacitance of 721 F g −1 at a current density of 1 A g −1 , while the specific capacitance of PPy, MoS 2 /PPy, and PPy/MnO 2 is only 179 F g −1 , 480 F g −1 , 270 F g −1 , respectively. The ternary composites supercapacitor exhibits a high mass power density of 3235.63 W/kg at an energy density of 40 Wh/kg. The cycling stability of MoS 2 /PPy/MnO2 material is also effectively improved compared to PPy/MnO 2 . After 5000 cycles, the capacitance of MoS 2 /PPy/MnO 2 is still 89.6 %, whereas that of PPy/MnO 2 is only 67.8 %. This research illuminates the fabrication of high-performance conducting polymer electrodes for wearable energy-storage devices.