Graphene-Wrapped Polyaniline Nanowire Array Modified Functionalized of Carbon Cloth for High-Performance Flexible Solid-State Supercapacitor

Graphene-wrapped polyaniline (PANI) nanowire array modified functionalized carbon cloth (fCC) (fCC-PANI array-rGO) is successfully fabricated and served as free-standing electrode for assembling flexible solid-state supercapacitors (SCs). Carbon cloth is functionalized so as to improve both hydrophilicity and capacitance, thus the vertically aligned PANI nanowire arrays are conducive to growth on fCC. After being wrapped with graphene, the fCC-PANI array-rGO electrode exhibits largest capacitance of 471 mF/cm² at 0.5 mA/cm². In addition, the graphene layer is employed as protective layer to alleviate swelling and shrinking of PANI in order to improve the cycle stability of fCC-PANI array-rGO. As a result, the free-standing electrode can maintain 75.5% of original capacitance even up to 10 000 cycles. Furthermore, the flexible solid-state SCs based on fCC-PANI array-rGO exhibit an outstanding area capacitance of 197 mF/cm² at current density of 0.1 mA/cm², keeping 91.3% of its original value after 7000 cycles at 5 mA/cm². Remarkably, the flexible solid-state SCs exhibit excellent mechanical properties and maintain about 100% of its capacitance, when bent at 180° after 500 cycles. Moreover, the flexible solid-state SCs are further employed as energy-storage device to light up a red, green, or yellow LED. Thus, the flexible solid-state SCs based on fCC-PANI array-rGO exhibit potential applications as a candidate for flexible energy-storage devices.