Ultrastable carbazole-tethered conjugated microporous polymers for high-performance energy storage

Abstract

Conjugated microporous polymers (CMPs) have considered as organic porous polymers featuring combination of p -conjugated skeletons with permanent micro-porosity. In the present study, we report the synthesis of carbazole-tethered conjugated microporous polymers, BC-Py-CMP and BC-BF-CMP, respectively, through the Suzuki-Miyaura coupling polymerization of the novel 3,3′,6,6′-tetraboronic-pinacolate-9,9′-bicarbazole (BC-4Bpin) with 1,3,6,8-tetrabromopyrene (Py-4Br) and 3,3′,6,6′-tetrabromo-9,9′-bifluorenylidene (BF-4Br). These CMPs exhibited extraordinary thermal stabilities (up to ca. 694 and 569 °C) and high surface areas (up to ca. 1030 m 2 g −1 ). Moreover, the as-prepared BC-BF-CMP exhibited a high specific capacitance of 260 F g −1 at 0.5 A g −1 and showed outstanding cycling stability, having 89.60% capacitance retention of its authentic capacitance over 6000 cycles. The excellent electrochemical capacitances of the BC-BF-CMP were presumably due to the 9,9′-BF could easily accept one electron, causing the reduced form acquiring greater aromaticity by meeting Huckel's requirements, as a result improving the electron transporting properties. Such CMPs tend to have tremendous potential to be used as a high-performance supercapacitors in energy storage systems. • Carbazole-tethered conjugated microporous polymers, CB-Py-CMP and CB-BF-CMP have been prepared. • CMPs exhibited extraordinary thermal stabilities (up to ca. 694 and 569 °C) and high surface areas (up to ca. 1030 m 2 g −1 ). • CB-BF-CMP showed a specific capacitance of 260 F g −1 at a current density of 0.5 A g −1 and an excellent cycling stability.