Formation of Monodisperse Carbon Spheres with Tunable Size via Triblock Copolymer-Assisted Synthesis and Their Capacitor Properties

A facile hydrothermal polymerization method has been developed for the preparation of monodisperse carbon spheres (MCSs) using the triblock copolymer F108 as surfactant. The synthesis is based on the ammonia-catalyzed polymerization reaction between phenol and formaldehyde (PF). The resultant MCSs have a perfect spherical morphology, smooth surface, and high dispersity. The particle sizes can be tuned in a wide range of 500~2400 nm by adjusting the dosage of the PF precursor. The activated MCSs with suitable heteroatoms (N and O) doped and a large specific surface area (960 m² g-¹) were obtained. A high-performance electrode of electrical double-layer capacitors fabricated by those active material have an excellent specific capacitance (310 F g^-1 at 0.5 A g^-1) and outstanding cycling stability (92% capacitance retention after 10,000 cycles). This work provides a new opportunity for the fabrication of MCSs with potential applications.