Asymmetric supercapacitors based on biomass-derived porous activated carbon (PAC)/1D manganese oxide (MnO2) electrodes with high power and energy densities

Young-Seok Lee, Aravindha Raja Selvaraj, Nikolaos Kostoglou, Claus Rebholz, Rajmohan Rajendiran, Vivekanandan Raman, Heeje Kim, John Anthuvan Rajesh, Vijay Mohan Nagulapati, Tae Hwan Oh, Peter Jerome, Sung-Shin Kim

Research output: Contribution to journalArticleResearchpeer-review

Abstract

In this study, we present the electrochemical performance of an asymmetric supercapacitor (ASC) composed of one-dimensional manganese oxide (MnO 2) nanorods embedded in porous activated carbon sheets (MnO 2/PAC) as the positive electrode (positrode), and renewable porous activated carbon (PAC) as the negative electrode (negatrode). This configuration facilitates a high rate of charge/discharge while maintaining substantial specific capacity. The MnO 2/PAC composite was successfully synthesized using a hydrothermal technique, while the PAC material was produced through pyrolysis reaction. The MnO 2/PAC composite exhibited a maximum specific capacitance of 208.75F g −1 at 0.5 A/g and demonstrated a cyclic stability of 87.43 % in neutral aqueous electrolytes. This notable electrochemical performance is attributed to the significant contribution of the high pseudo-capacitance offered by dense MnO 2 nanorods, in addition to the expansive surface area of the activated carbon sheets with closely packed structures. The ASC constructed as PAC//MnO 2/PAC displayed a high energy density of 23.3 Wh kg −1 and a power density of 350.4 W kg −1 at a current density of 0.5 A/g. Furthermore, the device showcased exceptional cycling stability, retaining 90.3 % at a current density of 4 A/g. These results underscore the substantial untapped potential of ASC devices for innovative applications in advanced energy storage.

Original languageEnglish
Article number117368
Number of pages10
JournalMaterials science and engineering B (Solid-state materials for advanced technology)
Volume304.2024
Issue numberJune
Early online date14 Apr 2024
DOIs
Publication statusPublished - Jun 2024

Bibliographical note

Publisher Copyright: © 2024 Elsevier B.V.

Keywords

  • 1D β-MnO nanorods
  • Asymmetric capacitors
  • Biomass derived hierarchically porous carbon
  • Pseudo capacitance

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