LAUSR

Abstract Hierarchical cobalt oxyhydroxide (CoOOH) nanostructures were directly grown on flexible stainless steel (SS) mesh substrates via a cost-effective, facile chemical solution method. The nanostructures were grown at 90 °C with different time intervals, and their morphological evolution and electrochemical performance were investigated. Initially, the nanowires and nanoparticles were randomly distributed on the surface of the SS mesh substrate. With increasing growth times, the nanowire-like structures were assembled as nanosheet-like structures having widths of ~20 nm. The small nanoparticles between the nanosheet-like structures agglomerated into large nanoparticles with a diameter of ~130 nm. The mixed nanosheet-like- and nanoparticle-structured CoOOH grown on the SS mesh substrate exhibited mass specific capacitances of ~383 F/g at 2 mV/s and ~176 F/g at 100 mV/s with excellent cycling stability (~96%, 3000 cycles).