Electropolymerization nanoarchitectonics of polyaminoanthraquinone/carbon cloth flexible electrode with nano-spines array structure for high-performance supercapacitor

Abstract

The construction of integrated flexible electrode materials with high density active sites, satisfactory and ideal nanostructures is of great significance for flexible supercapacitors, but it is still a huge challenge. Herein, we targeted select 1,5-diaminoquinone (DAAQ) with high theoretical capacity as monomer and used in-situ electropolymerization strategy to prepare the binder-free flexible poly (1,5-diaminoquinone)/carbon cloth electrode (EP-PDAAQ/CC). In the SEM images of EP-PDAAQ/CC, PDAAQ is uniformly covered on CC with nano-spines array structure. DFT calculations further demonstrate that the polymerization process can effectively reduce band gaps and improve the overall conductivity of electrode materials. Subsequently, we systematically investigate the core influencing factors affecting the electropolymerization process, such as monomer concentration, supporting electrolyte types, polymerization voltage and charge density. Under optimal preparation conditions, we found that EP-PDAAQ/CC exhibited a higher energy storage capacity (about 2.2 times) than PDAAQ/CC (prepared by chemical oxidative polymerization). And the flexible electrodes show the maximum specific capacitance of 645 mF cm−2 at 1 mA cm−2 and superior cycling stability (83.5 % of the initial capacity after 10,000 cycles). The kinetic analysis shows that the capacitance contribution of EP-PDAAQ/CC flexible electrode is as high as 78.1 % at 100 mV s−1, exhibiting fast electrochemical kinetic properties. Finally, we assemble the symmetrical supercapacitor and test its practical application.