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

P-doped hierarchical porous carbon aerogels are prepared by carbonizing the phloroglucin-formaldehyde resins in the presence of ZnCl 2 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 °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 at 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.