The construction of sea urchin spines-like polypyrrole arrays on cotton-based fabric electrode via a facile electropolymerization for high performance flexible solid-state supercapacitors

Abstract The most explored flexible supercapacitors based on PPy electrodes face a huge challenge of poor cycle performance. Here, we demonstrate successful construction of sea urchin spines-like PPy arrays on cotton-based fabric electrode via a facile electropolymerization and employ it in enhancing the cyclic stability of the supercapacitors without recombination of PPy with other capacitive materials. This novel fabric electrode (called EPPy-PPy/NF/CF) consists of a cotton fabric (CF) coated with PVA-co-PE nanofibers (NF) as a flexible substrate (NF/CF). The formation mechanism of the spiny PPy with nanocavities is explored, and the effects of surface wettability of the support electrode (PPy/NF/CF), micellar size, and bubble generation on the nucleation and growth of the PPy during electropolymerization are elucidated. Significantly, the flexible solid-state symmetrical EPPy-PPy/NF/CF supercapacitor exhibits striking cycling stability with 100% retention after 10000 cycles at a current density of 4 mA cm−2. The superior cyclic stability can be attributed to the spiny PPy arrays, which can shorten the transmission paths of counter ions and charges, thereby weakening stress-induced damages to the PPy skeleton. Additionally, this flexible supercapacitor also shows a great potential for application in portable and wearable electronic devices.