High‐Performance Supercapacitor Electrode Materials from Chitosan via Hydrothermal Carbonization and Potassium Hydroxide Activation. Issue 3 (17th August 2016)

• Record Type: Journal Article
• Authors: Zhu, Linfeng; Shen, Feng; Smith, Richard L.; Qi, Xinhua
• Is Part Of: Energy technology. Volume 5:Issue 3(2017:Mar.)
• Page Start: 452
• Page End: 460
• Publication Date: 2016-08-17
• Subjects: biomass -- carbon -- chitosan -- hydrothermal carbonization -- supercapacitors; Energy development -- Periodicals; Power resources -- Periodicals; 333.79
• DOI: 10.1002/ente.201600337
• Languages: English
• ISSNs: 2194-4288

Abstract

Abstract: Nitrogen‐rich porous carbonaceous materials suitable for supercapacitor applications can be synthesized directly from chitosan using a hydrothermal treatment (250 °C, 14 h) that is followed by chemical activation of the carbonized solids with KOH (ca. 800 °C, 2 h). The synthesized chitosan‐derived carbonaceous materials (CDCMs) had high specific surface area (ca. 2200 m 2 g −1 ), large pore volume (ca. 1.36 cm 3 g −1 ), and high nitrogen content (ca. 6.3 %). When a current density of 0.5 A g −1 was applied to CDCM‐800 obtained at an activation temperature of 800 °C, specific capacitances of 231 and 305 F g −1 were achieved for 0.5 m K2 SO4 and 6 m KOH aqueous electrolytes, respectively. Capacitances of 154 and 198 F g −1 were retained for the respective electrolytes at 20 Ag −1 . CDCM‐800 had an energy density of 8.5 Wh kg −1 corresponding to a specific power of 1 kW kg −1 at 20 A g −1 in 6 m KOH aqueous electrolytes. The prepared carbonaceous materials retained 99 % of their properties for over 3000 cycles at 1 A g −1 in 0.5 m K2 SO4 . The nitrogen‐rich nanoporous carbonaceous materials have wide application in energy, electrical, chemical, analytic, separation, and catalysis. Abstract : Crabby energy : Carbon‐based materials are an important class of materials used in supercapacitors as electrodes. Synthesis of such materials usually requires time‐ and energy‐intensive procedures. Therefore, the use of biomass‐based starting materials would be beneficial. We prepare a carbonaceous material through carbonization of chitosan using a hydrothermal treatment which is followed by KOH activation. The resulting material has a high stability at high discharge currents in aqueous electrolytes.