Influence of Multiwalled Carbon Nanotubes as Additives in Biomass Derived Carbons for Supercapacitor Applications

• Type: Article in International Scientific Journal
• Date: 2019-01-17

Authors

José Inácio Martins (Author) FEUP; Natalia Rey-Raap (Author) FEUP; Marina Enterria (Author) Other; Manuel Fernando R. Pereira (Author) FEUP; José Luís Figueiredo (Author) FEUP

Journal

Title: ACS Applied Materials & Interfaces

Vol. 11 No. 6

Pages: 6066-6077

ISSN: 1944-8244

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge

ISI Web of Science

Scopus

Other information

DOI: 10.1021/acsami.8b19246

Abstract (EN): Glucose-derived carbon/carbon nanotube (CNT) hybrid materials were prepared by hydrothermal carbonization of glucose in the presence of CNTs and subsequent carbonization, physical activation, or chemical activation. The proportion of CNTs added during the hydrothermal polymerization of glucose was varied to ascertain the optimum dose to maximize the performance of the carbon hybrids in supercapacitor applications. Both the thermal treatment applied and the addition of CNTs lead to changes in the textural and chemical properties of the activated carbons. It was observed that samples bearing CNTs exhibit higher number of nucleation centers for glucose oligomers to polymerize, and consequently, the behavior of the hydrothermal carbon toward activation differs according to the activating agent employed. Moreover, the initial chemical speciation dominated by acidic groups shifts to more basic functionalities (quinones and carbonyl groups) with the addition of CNTs. The effect of the different physicochemical properties of the prepared carbons on their electrochemical behavior was evaluated. The addition of 2 wt % of CNTs and subsequent chemical activation leads to electrode materials yielding 206 F g(-1) and 78% of capacitance retention up to 0.8 V and 20 A g(-1) and high rate cyclability (97% after 5000 cycles). The outstanding performance is ascribed to the high surface area, narrow mesopores, and phenol/carbonyl surface functionalities, which enhance molecular diffusion, the amount of stored energy, and electronic transportation, respectively.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12