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Liu C, Li C, Ahmed K, Mutlu Z, Lee I, Zaera F, Ozkan CS, Ozkan M. High-Potential Metalless Nanocarbon Foam Supercapacitors Operating in Aqueous Electrolyte. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1702444. [PMID: 29493117 DOI: 10.1002/smll.201702444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 12/22/2017] [Indexed: 06/08/2023]
Abstract
Light-weight graphite foam decorated with carbon nanotubes (dia. 20-50 nm) is utilized as an effective electrode without binders, conductive additives, or metallic current collectors for supercapacitors in aqueous electrolyte. Facile nitric acid treatment renders wide operating potentials, high specific capacitances and energy densities, and long lifespan over 10 000 cycles manifested as 164.5 and 111.8 F g-1 , 22.85 and 12.58 Wh kg-1 , 74.6% and 95.6% capacitance retention for 2 and 1.8 V, respectively. Overcharge protection is demonstrated by repetitive cycling between 2 and 2.5 V for 2000 cycles without catastrophic structural demolition or severe capacity fading. Graphite foam without metallic strut possessing low density (≈0.4-0.45 g cm-3 ) further reduces the total weight of the electrode. The thorough investigation of the specific capacitances and coulombic efficiencies versus potential windows and current densities provides insights into the selection of operation conditions for future practical devices.
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Affiliation(s)
- Chueh Liu
- Materials Science and Engineering Program, Department of Electrical Engineering, Department of Chemistry, University of California, Riverside, CA, 92521, USA
| | - Changling Li
- Materials Science and Engineering Program, Department of Mechanical Engineering, Department of Electrical Engineering, University of California, Riverside, CA, 92521, USA
| | - Kazi Ahmed
- Materials Science and Engineering Program, Department of Electrical Engineering, Department of Chemistry, University of California, Riverside, CA, 92521, USA
| | - Zafer Mutlu
- Materials Science and Engineering Program, Department of Mechanical Engineering, Department of Electrical Engineering, University of California, Riverside, CA, 92521, USA
| | - Ilkeun Lee
- Department of Chemistry, University of California, Riverside, CA, 92521, USA
| | - Francisco Zaera
- Department of Chemistry, University of California, Riverside, CA, 92521, USA
| | - Cengiz S Ozkan
- Materials Science and Engineering Program, Department of Mechanical Engineering, Department of Electrical Engineering, University of California, Riverside, CA, 92521, USA
| | - Mihrimah Ozkan
- Materials Science and Engineering Program, Department of Electrical Engineering, Department of Chemistry, University of California, Riverside, CA, 92521, USA
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