Three-dimensional heterostructured polypyrrole/nickel molybdate anchored on carbon cloth for high-performance flexible supercapacitors

The urgent demands of energy storage for wearable electronics necessitates the development of flexible supercapacitors (FSCs). However, the service environment of portable/wearable devices requires supercapacitors to possess excellent mechanical properties to withstand harsh straining conditions, such as bending, rolling, and twisting. Hence, to develop a high-performance flexible supercapacitor (FSC) that possesses both superior electrochemical properties and remarkable mechanical capacities is still a formidable challenge. In this paper, we successfully fabricate a 3D heterostructured electrode with bulge structured polypyrrole (PPy) wrapped NiMoO₄ nanowires on carbon cloth (CC). Benefiting from the 3D heterostructure and the synergistic effect between NiMoO₄ and PPy, the PPy/NiMoO₄/CC electrode shows a high areal capacitance of 3.4 F cm⁻² and cyclic stability (94% capacitance retention). Moreover, the assembled PPy/NiMoO₄/CC//activated carbon (AC)/CC device exhibits a high energy density (0.5 mW cm⁻² at a power density of 3.7 mWh cm⁻²). Furthermore, the CV curves of PPy/NiMoO₄/CC//AC/CC show no obvious change under miscellaneous deformation conditions, indicating good flexibility. This work demonstrates that the assembled PPy/NiMoO₄/CC//AC/CC FSC possesses notable electrochemical properties and exhibits great potential for application in future wearable energy-storage devices.