Preparatory Conditions Optimization and Characterization of Hierarchical Porous Carbon from Seaweed as Carbon-Precursor Using a Box—Behnken Design for Application of Supercapacitor

Abstract

This study has developed an environmentally friendly, simple, and economical process by utilizing seaweed as a carbon precursor to prepare a hierarchical porous carbon for the application of a supercapacitor. In the carbonization process, the design of experiment (DOE) technology is used to obtain the optimal preparatory conditions with the best electrochemical properties for the electrode materials of supercapacitors. Without using strong acid and alkali solution of the green process, NaCl is used as the pore structure proppant of seaweed (SW) for carbonization to obtain hierarchical porous carbon material to improve the pore size distribution and surface area of the material. In the experiment of SW activation, the interaction between factors has been explored by the response surface methodology (RSM) and Box–Behnken design, and the optimal conditions are found. The activated carbon with the specific surface area of 603.7 m2 g−1 and its capacitance reaching 110.8 F g−1 is successfully prepared. At a current density of 1 A g−1, the material still retains 95.4% of the initial capacitance after 10,000 cycles of stability testing. The hierarchical porous carbon material prepared by the design of experiment planning this green process has better energy storage properties than supercapacitors made of traditional carbon materials.