Bio-Inspired Energy Storage Electrode: Utilizing Co₃O₄ Hollow Spheres Derived from Sugarcane Bagasse Extract Synthesis Via Hydrothermal Route

Recent research has explored the utilization of sugarcane bagasse, a bio-industrial waste, to fabricate energy storage devices due to ecofriendly nature, low cost with industrial scale production. In this investigation, cobalt oxide hollow spheres (Co₃O₄ HSs) were synthesized from waste sugarcane bagasse extract with the carbon spheres (CSs) act as template. The main component of sucrose (C₁₂H₂₂O₁₁) linked with cellulose fibers and other oxygenic functional groups were used to prepare CSs. Previously, a metal precursor (Co(NO₃)₂.6H₂O) was mixed with sugarcane bagasse extract and subjected to a hydrothermal process, resulting in uniform-sized metal CSs. The uniform sized Co₃O₄ HSs were formed by calcined metal CSs. The calcination temperature plays a crucial role to eliminating implanted carbon material on inter surface area of the metal oxide, shaping the Co₃O₄ HSs. Structural, vibrational, morphology and elemental analyses were confirmed by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), respectively. Electrochemical tests show improved ion transport and low resistance, leading to high capacitance in asymmetric supercapacitor (ASC) devices. Subsequently, for asymmetric supercapacitor (ASC) devices, using with Co₃O₄ HSs has function of cathode and activated carbon (AC) as anode, the devices demonstrated impressive results of 33.1 Fg^− 1 at 1 Ag^− 1, 86.8% retention after 4,000 cycles, as well as the energy density and power density of 5.9 W h kg^− 1 at 1500 W kg^− 1. The Co₃O₄ HSs||AC device exhibits promising energy storage properties for future applications.