Synthesis of porous carbon materials derived from laminaria japonica via simple carbonization and activation for supercapacitors

High-performance electrode materials derived from biomass for supercapacitors have been considered as an effective solution to the problems of the fossil energy shortage and the environment deterioration. Most importantly, the specific capacitance, rate performance and cyclic stability for these electrode materials are focused issues. Here, we prepare a new type porous carbon using laminaria japonica as the carbon source via a simple carbonization and activation method, and investigate its morphology, structure and electrochemical properties. The results show that the porous carbon materials exhibit amorphous structure, high specific surface area with abundant pores and oxygen functional groups. The specific capacitance of the porous carbon with a large specific surface area of 1902.42 m² g⁻¹ and total pore volume of 1.26 cm³ g⁻¹ can reach to 192 F g⁻¹ at 0.1 A g⁻¹. Furthermore, this porous carbon possesses a specific capacitance of 120 F g⁻¹ at 10 A g⁻¹, nearly 100% capacitance retention rate and coulomb efficiency after 10000 cycles at 1 A g⁻¹, indicating excellent rate performance and cyclic stability. Therefore, as-prepared porous carbons derived from laminaria japonica with low cost, easy availability, high regeneration ability and sustainability have a promising application as the electrode materials for supercapacitors.