High-performance supercapacitors fabricated with activated carbon derived from lotus calyx biowaste. (April 2022)

• Record Type: Journal Article
• Authors: Dhakal, Ganesh; Mohapatra, Debananda; Kim, Young-Il; Lee, Jintae; Kim, Woo Kyoung; Shim, Jae-Jin
• Is Part Of: Renewable energy. Volume 189(2022)
• Page Start: 587
• Page End: 600
• Publication Date: 2022-04
• Subjects: Biowaste -- Lotus calyx -- 3D carbon structure -- Aqueous electrolyte -- Ionic liquid electrolyte -- Symmetric supercapacitor; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2022.01.105
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: The clean, green, and renewable energy source and its storage have attracted considerable interest from both industry and academia to address the ongoing global climate change. The waste biomass-derived porous carbon is an important research topic complementing its low-cost, eco-friendly, and renewable nature. Three-dimensional (3D) porous carbon was prepared by the one-step simultaneous carbonization and activation of natural lotus ( Nelumbo nucifera ) calyx. The as-prepared 3D-lotus calyx-derived activated carbon (3D-LCAC) electrode, with a specific surface area of 798 m 2 g −1 delivered a remarkable specific capacitance of 223 F g −1 at 1 A g −1, with exceptionally high cycling stability, showing 97% retention of its initial capacitance, even after 50, 000 charge-discharge cycles in a KOH electrolyte. It also demonstrated superior rate capability approximately 3-times higher than the commercial AC. The electrochemical performance of the 3D-LCAC electrode in a symmetric supercapacitor device was measured in aqueous (6 M KOH, 1 M Na2 SO4 ) and ionic liquid (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) electrolytes. The ionic liquid electrolyte facilitated 3D-LCAC symmetric supercapacitor device delivered approximately ten-times higher energy density than that of aqueous electrolytes under similar electrochemical conditions. Overall, the 3D-LCAC from renewable and sustainable biowaste is a good candidate for high-performance electrode materials in practical supercapacitor applications. Graphical abstract: Image 1