Rational hybrid modulation of P, N dual-doped holey graphene for high-performance supercapacitors

• Published in: Journal of power sources Vol. 372; pp. 286 - 296
• Main Authors: Nazarian-Samani, Masoud, Haghighat-Shishavan, Safa, Nazarian-Samani, Mahboobeh, Kim, Myeong-Seong, Cho, Byung-Won, Oh, Si-Hyoung, Kashani-Bozorg, Seyed Farshid, Kim, Kwang-Bum
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 31.12.2017
• Subjects: Acid catalyst; Doping; Holey graphene; sp2→sp3 transition; Supercapacitor; Supercapacitor; sp2→sp3 transition; Acid catalyst; Holey graphene; Doping
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2017.10.087

A P, N dual-doped holey graphene (PNHG) material is prepared by a scalable, facile synthetic approach, using a mixture of glucose, dicyandiamide (DCDA), and phosphoric acid (H3PO4). H3PO4 successfully functions as an “acid catalyst” to encourage the uniform breakage of C=C bonds to create large, localized perforations over the graphene monolith. Further acid treatment and annealing introduce in-plane holes. The correlation between the capacitance of the PNHG and its structural parameters during the fabrication process is comprehensively evaluated. A thermally induced sp2→sp3 transformation occurs at high temperatures because of the substantial loss of graphitic sp2-type carbons, together with a dramatic reduction in capacitance. The target PNHG-400 electrode material delivers exceptionally high gravimetric capacitance (235.5 F g−1 at 0.5 A g−1), remarkable rate capability (84.8% at 70 A g−1), superior capacitance retention (93.2 and 92.7% at 10 and 50 A g−1 over 25000 cycles, respectively), and acceptable volumetric capacitance due to moderate density, when it is used with organic electrolytes in the voltage range between 0 and 3 V. These results suggest a pioneering defect-engineered strategy to fabricate dual-doped holey graphene with valuable structural properties for high-performance electric double layer supercapacitors, which could be used in next-generation energy storage applications. Fabrication of well-designed defect-laden holey graphene counterparts for energy-related applications using a simple, up-scalable and cost-effective strategy. [Display omitted] •Rationally designed P, N dual-doped holey graphene as an electrode in supercapacitors.•Importance of synergistic ion transport with a high content of C=C bonds.•Occurrence of sp2→sp3 transition in graphene structure at temperatures higher than 400 °C.•High capacitance, excellent rate capability and cyclic stability of the target PNHG-400.•Novel approach to develop future supercapacitors with high energy and power densities.