Synthesis of hierarchically macro/meso/microporous carbon spheres and its application in fast rechargeable electric double layer capacitor

A porous carbon sphere (PCS), which exhibits hierarchical macro/meso/microporosity, is fabricated by nanocasting. The macropores within the PCS are penetrable, fully open and well interconnected, which is admirable for fast mass transfer applications. The carbon has been attempted as a novel electrode material for a fast rechargeable electrochemical double layer capacitor (EDLC). Though the total surface area is only 826 (+/-2) m(2) g(-1) and a large quantity of micropores exist, the capacitance of the EDLC can reach 172 (+/-3) F g(-1) regardless of the cyclic voltammetry scan rate. The macropores within the PCS acted as ion-buffering reservoirs in-situ, which facilitates the accessibility of the mesopores as well as the micropores within the PCS. As a result, unlike traditional microporous carbon material, the micropores in the PCS show no obvious negative effect to the performance of the EDLC. The PCS material is a promising candidate in fast mass transfer applications. (C) 2012 Elsevier B.V. All rights reserved.