Meso- and micro- porous composite carbons derived from humic acid for supercapacitors

• DOI: 10.1016/j.electacta.2014.05.115
• Publication Date: 2014-06-02T18:19:53Z
• Authors: Jiao Yin; Duanyi Zhang; Jiquan Zhao; Xiaolei Wang; Hui Zhu; Chuanyi Wang
• Keywords: Specific surface area; Horizontal scan rate

Abstract Herein, humic acid (HA), a kind of biomass (natural polymer), is firstly adopted as a raw material for synthesis of activated carbons (ACs) via a high-temperature activation procedure with KOH. Their porous textures as well as surface groups are fully characterized by N 2 sorption isothermal analysis, SEM, TEM, XPS and IR, respectively. The HA-derived ACs show very high specific surface areas (up to 2990.32 m 2 g −1 ). Furthermore, electrochemical studies such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge (GCD) are carried out to evaluate their specific capacitance and rate capability. It reveals that HA-derived ACs possess high specific capacitance (350 Fg −1 ) at a scan rate of 5 mV s −1 in 1 M H 2 SO 4 . Moreover, supercapacitors based on HA-derived ACs demonstrate good cycling stability in which the 92% initial capacitance has been retained even after 9000 cycle numbers at a high current density of 1 A g −1 .