P-doped hierarchical porous carbon aerogels derived from phenolic resins for high performance supercapacitor

摘要

P-doped hierarchical porous carbon aerogels are prepared by carbonizing the phloroglucin-formaldehyde resins in the presence of ZnCl2 and subsequently being activated by KOH. Phosphoric acid is simultaneously used as the polymerization catalyst and P-doped agent in the preparation procedure. Compared with un-doped sample, P-doped carbon with hierarchical porous structure shows improved electrochemical performance. The prepared sample that activated at 800 degrees C exhibits good capacitance of 406.2 F g(-1) in 6 M KOH at a scan rate of 5 mV s(-1). When the scan rate is 500 mV s(-1), the specific capacitance still reaches to 267.4 F g(-1), demonstrating good rate capability. When 60 mg of active materials is loaded, the mass specific capacitance of the prepared electrode reaches to 348.8 F g(-1) M a scan rate of 5 mV s(-1), and the maximum area capacitance is 11.35 F cm(-2). The energy density of the prepared sample is as high as 16.97 Wh kg(-1) at a power density of 200 W kg(-1) and reaches to 8.52 Wh kg(-1 )at 2000 W kg(-1). Importantly, after 100,000 charging and discharging cycles, the specific capacitance of the prepared sample is no attenuated, indicating a long-term electrochemical stability.