A facile drop-casting approach to nanostructured copper oxide-painted conductive woven textile as binder-free electrode for improved energy storage performance in redox-additive electrolyte

Hierarchical copper oxide (CuO) nanostructures (NSs) with caterpillar-like morphologies were facilely integrated onto a highly flexible conductive woven textile substrate (CWTs) by a drop-casting approach. Initially, the CuO NSs were synthesized via a simple and green wet-chemical method in 30 min and the obtained colloidal solution of CuO was easily dropped onto well-cleaned CWTs. By virtue of their interesting structural features, the caterpillar-like CuO NSs on CWTs were employed as binder-free electrodes for supercapacitors and their electrochemical properties were investigated in 1 M KOH solution. Additionally, a small portion of redox-additive potassium ferricyanide (K3Fe(CN)6) was added to the 1 M KOH solution, which led to efficient enhancement of energy storage performance with superior cycling stability for the caterpillar-like CuO NSs on CWTs. Furthermore, the fabricated asymmetric supercapacitor (SC) with CuO NSs on CWTs and activated carbon with an operating potential window of 1.5 V simultaneously exhibited excellent energy density and power density values. Such a simple and low-cost approach to easily construct metal oxide nanomaterials on flexible textiles with redox-additive electrolyte may be useful for several potential applications in high-performance energy storage devices.