Advancements in the utilization of nanocarbon sphere composites in supercapacitor

Supercapacitors, as a novel type of energy storage device, have garnered significant attention due to their outstanding charging and discharging rates, high power density, and safe operation. Electrode materials, crucial components of supercapacitor devices, directly influence the electrochemical performance. Hollow carbon spheres (HCSs) have emerged as noteworthy candidates in energy storage and conversion, particularly in high-performance supercapacitors, owing to their well-defined morphology, uniform size (100 μm to 3 nm), low density, and extensive surface area (300–2221 m² g⁻¹). Substantial advancements have been achieved in developing advanced supercapacitor electrode materials incorporating hollow carbon sphere structures. This paper provides a comprehensive overview and discussion of the preparation of hollow spheres with controllable structure and morphology. Additionally, it explores various methods employed in recent years to enhance HCS, encompassing variations in doping elements and adjustments in content and composite types. The primary objective of this paper is to elucidate the application of HCS as electrode materials in supercapacitors and to serve as a reference for further research on HCS-based materials.