Chitosan-based porous carbon materials (CSPC)were prepared by a one-step carbonization-activation supplemented with a freeze-drying method. The structural morphology and chemical composition of the materials prepared at different activator ratios were characterized by scanning electron microscopy (SEM),X-ray diffraction (XRD),Raman spectroscopy (Raman),X-ray photoelectron spectroscopy (XPS)and nitrogen adsorption and desorption test (BET),and their electrochemical properties were investigated. The test results show that CSPC had a rough surface with a high specific surface area of 2 178. 9 m2·g-1,a hierarchical porous structure and a high mesoporosity,and was rich in heteroatoms such as nitrogen and oxygen,which endows the electrode material with good electrical conductivity,good wettability and fast ion diffusion performance,enabling it to exhibit excellent capacitive properties. When the mass ratio of activator to chitosan was 1 ∶ 1,the specific capacity of porous carbon (CSPC-1. 0)was as high as 386. 0 F·g-1 at a current density of 0. 5 A·g-1,and when the current density was 20 A·g-1,its specific capacitance was still as high as 319. 6 F·g-1,showing excellent rate performance;meanwhile,at a current density of 5 A·g-1,the electrode had 94. 4% specific capacity retention after 10 000 charge/ discharge cycles,showing excellent cycling stability. A symmetrical supercapacitor assembled with CSPC-1. 0 as the electrode active substance could achieve an energy density of 15. 5 Wh·kg-1 at a power density of 300 W·kg-1. The chitosan-based porous carbon with a hierarchical structure prepared in this work has a promising application as an energy storage material. © 2023 Cailiao Daobaoshe/ Materials Review. All rights reserved.
