Hybrid crumpled graphene supported Fe-Co binary oxides nanoparticles for aqueous asymmetric supercapacitors

Asymmetric supercapacitors are considered promising energy storage devices due to their high applied voltage and corresponding high energy density. Herein, Fe-Co binary oxides nanoparticles loaded crumpled graphene (CGR) composites were prepared for use as the positive electrode material of asymmetric supercapacitors (ASC) using aerosol spray pyrolysis and post heat-treatment processes. The composites showed a crumpled paper like morphology and were around 1 µm in average diameter. Asymmetric electrode structures were fabricated using the composites as the positive electrode and CGR as the negative electrode. Electrochemical measurement of the ASC indicated excellent capacitive performance, which resulted in high energy density (36 W h kg−1) and long-term cycling stability after 2000 cycles at a current density of 1 A g-1.