B-Doped Carbon Powder Synthesized from PU/PF/GO Composite as Electrode Material for Supercapacitors

Graphite is a vital natural mineral material that is used to synthesize graphene oxide. In the present study, polyurethane/phenolic/graphene oxide composite materials were prepared from polyisocyanate prepolymer, phenolic resin prepolymer, and graphene oxide then treated with boric acid, ferric chloride, and zinc chloride and carbonized at high temperatures to synthesize boron-doped carbon powder (UFGC-B-Fe-Zn). The UFGC-B-Fe-Zn exhibited a Brunauer–Emmett–Teller specific surface area SBET of 885.9759 m2 g−1 and a specific pore volume of 0.550491 cm3 g−1, as well as high specific capacitance of 377.4 F g−1 at 0.5 A g−1. Used as an electrode material for supercapacitors, UFGC-B-Fe-Zn exhibited excellent rate capability and durability as well as low charge and ion diffusion resistance. In 6 M KOH electrolyte, the assembled symmetrical supercapacitor achieved relatively high energy density of 7.43 Wh kg−1 at 474 W kg−1. Moreover, it displayed excellent cycling stability (90.9% retention rate after 5000 cycles).