Camellia pollen-derived carbon for supercapacitor electrode material

Abstract Carbon materials derived from pollen for supercapacitor electrode are feasibly prepared through a hydrothermal process with controlled content of ammonium borofruoride (NH 4 BF 4 ) and subsequent carbonization. The effect of NH 4 BF 4 on the morphology, microstructure, chemical state, texture structure and the electrochemical performance of the products are studied. It is found that the sample treated by 0.015 g ml −1  NH 4 BF 4 during the hydrothermal process shows the highest specific surface area of 526 m 2  g −1 as well as the largest specific capacitance of 205 F g −1 at a current density of 0.5 A g −1 in 2 M KOH solution [128% of the sample hydrothermal treated without NH 4 BF 4 (161 F g −1 ) at the same specific current]. The cycle measurement demonstrates the excellent cycling stability of CH-0.015, while 96.2% of its initial capacitance can be retained after 10000 cycles. Furthermore, the contribution of electrical double-layer capacitance and the pseudocapacitance of the samples is uncovered.