Preparation and electrochemical properties of high-performance activated carbon based on self-assembly of seaweed template

In recent years, porous carbon prepared by the self-template method receives much attention due to its excellent structural controllability. However, carbon materials have a comparatively small number of self-templates, and removing templates often provides inadequate activation sites. Based on the self-assembly of seaweed templates, this study uses Ca2+ to chelate with the G-G units in alginate to form a reticulated macromolecular structure, thereby increasing the unique "egg-box" structure of calcium alginate in seaweed. Subsequently, a large number of "egg-box" initial pore structures are successfully formed inside and outside the seaweed raw material by removing the Ca2+ template, making it an exceptional electrode material for supercapacitors. The template selfassembly solves the problem of insufficient templates in the carbon materials, and successfully introduces the "egg-box" initial pore structures that can optimize the pore structure and increase the specific surface area, significantly improving the electrochemical performance of the porous carbon materials. The results show that the specific surface area of SACCa2 constructed by self-assembly of seaweed templates is 3093.4 m2 g- 1, and its specific capacitance reaches up to 256.0 F g- 1 when the current density is 0.5 A g- 1. The capacitance retention rate of SACCa2 reaches up to 93.43 % after 5000 times of charging and discharging, which exhibits excellent cycling stability.