Beyond hierarchical mixed nickel-cobalt hydroxide and ferric oxide formation onto the green carbons for energy storage applications.

To attain superior energy density concurrently with high power density, high-performance supercapacitors have been developed. Herein an innovative strategy has been adopted to fabricate unique binder-free electrodes composed of a unique porous structure of binary metal carbonate hydroxide nanomace-decorated hydrothermal porous carbon spheres (PCSs). Hierarchical nickel-cobalt carbonate hydroxide (NiCOCH) nanomaces, directly grown on PCSs, are used as positive electrodes for supercapacitors fabrication. Furthermore, FeO@PCS composites, having benefits of highly reversible redox reaction in the negative potential window and highly porous structure, are employed as the negative electrode in the fabrication of the asymmetric supercapacitors (ASCs). The assembled NiCoCH@PCS// FeO@PCS asymmetric devices with a wide electrochemical potential window not only have the merit of high energy and power densities but also receive benefits from remarkable cycle stability. These encouraging outcomes that are mutually beneficial, make these fabricated ASCs significantly ideal for high-performance electronics.