The excellent capacitive capability for N,P-doped carbon microsphere/reduced graphene oxide nanocomposites in H2SO4/KI redox electrolyte

• Published in: Journal of materials science 2019-05, Vol.54 (10), p.7665-7678
• Main Authors: Sun, Qimeng, Li, Yueming, He, Tao
• Format: Article
• Language: English
• Subjects: Aqueous electrolytes; Aqueous solutions; Capacitance; Carbon; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Composites; Crystallography and Scattering Methods; Electrode materials; Electrodes; Electrolytes; Flux density; Graphene; Hydrothermal treatment; Materials Science; Microspheres; Nanocomposites; Nitrogen; Phosphorus; Polymer Sciences; Porosity; Solid Mechanics; Structural hierarchy; Sulfuric acid; Supercapacitors
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-019-03414-x

In order to ameliorate the capacitance and energy density of supercapacitors in aqueous electrolytes, nitrogen- and phosphorus-codoped carbon microspheres/reduced graphene oxide nanocomposites are obtained by hydrothermal treatment of graphite oxide and N,P-doped carbon microsphere. The as-prepared nanocomposites display a high specific surface area of 604.3 m 2  g −1 and hierarchical pore structure composed of micropores, mesopores, and macropores. N,P-codoped carbon microspheres/reduced graphene oxide are used as electrode materials in the redox electrolyte of H 2 SO 4 and KI aqueous solution, exhibiting a excellent capacitance performance of up to ~ 654 F g −1 at 2 A g −1 , corresponding to the energy density of 14.53 Wh kg −1 at power density of 402 W kg −1 . Even at a high current of 20 A g −1 , the electrode can keep a capacitance of 318 F g −1 , showing an energy density of 7 Wh kg −1 at power density of 3984 W kg −1 . This study indicates the potential of nitrogen- and phosphorus-codoped carbon microspheres/reduced graphene oxide in high energy density supercapacitor.