Highly Stable CuS Nanotrough‐Networks Constructed on Arbitrate Substrate for Flexible Supercapacitor

Abstract

Herein, supercapacitors (SC) are fabricated on arbitrary flexible substrates by constructing copper sulfide nanotrough‐network and electrodeposition of polyaniline (PANI@CuS NN) as electrode. Attributed to its unique hollow structure, the CuS NN current collector demonstrates high conductivity (10.4 Ω □−1) and mechanical flexibility (within 2.3% relative resistance change after more than 1,000 bending times at the radius of 4 mm). The obtained PANI@CuS NN electrode demonstrates more than 218.28 F g−1 specific capacity at the current density of 1 A g−1, remaining 85.08% of the original capacity after 1,000 cycles (5 A g−1). This can be attributed to that CuS NN provides abundant attachment sites for PANI by the large specific surface area. Additionally, a flexible solid‐state supercapacitor is constructed by coating silk fibroin hydrogel as the electrolyte between the PANI@CuS NN and another CuS NN electrode loaded with multiwalled carbon nanotubes (MWCNTs@CuS NN). The capacity is 107.8 F g−1 at the current density of 0.25 A g−1 with excellent cycling stability.