Self-organized bowl-like hollow carbon submicrospheres with hierarchical mesopore-rich structure as superior electrode materials for supercapacitors

The design and development of bowl-like hollow carbon submicrospheres (BHCSs) with hierarchical porous structure as a new class of hollow carbon structure has recently attracted increasing attention. Herein, the coarse bowl-like hollow carbon submicrospheres (CBHCSs), smooth bowl-like hollow carbon submicrospheres (SBHCSs) with hierarchical mesopore-rich structure and their hollow carbon submicrospheres (HCSs) counterparts were prepared through a facile sequential heterogeneous nucleation route by changing the temperature and the molar concentration of reactants. The electrochemical measurements reveal that the CBHCS electrode displays a high specific capacitance of 294 F g(-1) at 1 A g(-1) because of the large specific surface area and superior cycling performance with 89.58% of its initial capacitance over 10,000 cycles due to its hierarchical mesopore-rich structure, while the SBHCS electrode shows the best rate capability with 55% of capacity retention at 20 A g(-1) resulted from their thinner shell of hollow carbon submicrospheres. Obviously, the differences of electrochemical performances can be mainly ascribed to the morphology, specific surface area, hierarchical porous structure and hollow shell thickness of these as-prepared samples. The superior capacitive behaviors coupled with the facile and low-cost preparation approach render BHCSs as highly prospective electrode materials for application in supercapacitors or other energy storage systems.