“Egg-box”-assisted preparation of hierarchical porous carbon with excellent electrochemical property

Based on the "egg-box" structure of calcium alginate in enteromorpha prolifera (EP), the carbonized products of EP are treated by HCl pickling to remove Ca2+ ions from calcium alginate and form the "egg-box" model initial pore structure. Then EP-based activated carbon is prepared by KOH activation method with the treated carbonized products as precursors. The pore characteristics and electrochemical properties of EP-based activated carbon are studied. The existence of hierarchical porous structures in EP-based activated carbon leads to a high specific surface area (SBET) up to 3283 m2 g−1, with more than 66% surface area provided by mesopores. This hierarchical porous carbon shows excellent electrochemical property when used as electrode materials for a supercapacitor, even at high current densities. The gravimetric capacitance value of the EP-based activated carbon reaches up to 361 F g−1 at the current density of 0.1 A g−1, the capacitance even remains at 323 F g−1 at the current density of 10 A g−1, demonstrating excellent high-rate capacitive performance.