Hierarchically Porous Biomass Carbon Derived from Natural Withered Rose Flowers as High‐Performance Material for Advanced Supercapacitors
Abrar Khan, Raja Arumugam Senthil, Junqing Pan, Yanzhi Sun, Xiaoguang Liu
Abstract
Abstract Herein, a hierarchically porous carbon was derived from the natural withered rose flower (denoted as RDPC) through a facile two‐step method of carbonization and chemical activation with a mixture of KOH/KNO 3 . The as‐derived RDPC contains an enlarged specific surface area of 1980 m 2 g −1 , better electrical conductivity and hierarchical porous architectures. Under three‐electrode system with 6 M KOH electrolyte, the RDPC displays a wonderful electrochemical activity as supercapacitor electrode including of ultrahigh SC (350 F g −1 at 1 A g −1 ), superb rate ability (165 F g −1 even at 150 A g −1 ) and remarkable durability (only 4.4 % fading rate of capacitance after 140,000 cycles at 100 A g −1 ). The RDPC based symmetric supercapacitor with 6 M KOH electrolyte supplies the highest energy density of 15.6 Wh kg −1 at 499 W kg −1 with only 3.5 % decay rate of capacitance over 15,000 cycles at 20 A g −1 , which is revealing the excellent real application of RDPC in the supercapacitor. This extraordinary electrochemical performance of RDPC can be attributed to its uniform interconnected layered‐like morphology, hierarchical porous networks, large specific surface area and fast electrochemical kinetics. Therefore, it is indicating that a facile and inexpensive designing of porous carbon from naturally available withered rose flowers and is a more sustainable electrode material for advanced energy storage related applications.