Bulk and surface modification of highly porous carbon for super capacitors tested at increased working voltages

摘要

Modifying the surface of highly porous carbon cryogels can affect the microstructure and electrochemical properties when used as electrodes for supercapacitors. For example, carbon cryogels modified with boron and nitrogen exhibit an increased pore volume while maintaining a similar number of pores below 5 nm in diameter when compared to unmodified porous carbon prepared under the same conditions. Additionally, the B and N modified carbon possessed 30% higher specific capacitance than unmodified carbon at higher frequencies. This improved capacitive behavior has been observed in carbon materials due to the presence of active species, which contribute to the total specific capacitance by the pseudocapacitive effect.