Supercapacitor electrode with high charge density based on boron-doped porous carbon derived from covalent organic frameworks
Shigeyuki Umezawa, Takashi Douura, Koji Yoshikawa, Yohei Takashima, Mika Yoneda, Kazuma Gotoh, Vlad Stolojan, S. Ravi P. Silva, Yasuhiko Hayashi, Daisuke Tanaka
Abstract
We developed a facile and unique process for preparing boron-doped porous carbon by direct carbonization of a boron-based covalent organic framework (COF-5). Boron oxides, which are formed during the carbonization of COF-5, were readily removed through water treatment of the resulting carbon to obtain boron-doped porous carbon. Thus, boron atoms were successfully incorporated into the carbon matrix. Supercapacitor electrodes made of the fabricated boron-doped carbon exhibited a specific capacitance of 15.3 μF cm−2 at 40 mA g−1, which is twice that of the conventional activated carbon electrode (∼6.9 μF cm−2) at the same current density, owing to the presence of boron atoms in the carbon material. The supercapacitors based on boron-doped carbon demonstrated 72% capacitance retention after 10000 charge/discharge cycles. The boron-doped COF-derived carbon materials can serve as a new class of multifunctional carbon materials for energy storage devices.