A novel supercapacitor electrode structure has been developed in which a uniform and conformal coating of nanostructured Ni(OH)2 flakes on carbon microfibers is deposited in situ by a simple chemical bath deposition process at room temperature. The microfibers conformally coated with Ni(OH) 2 nanoflakes exhibit five times higher specific capacitance compared to planar (non-conformal) Ni(OH)2 nanoflake electrodes prepared by drop casting of Ni(OH)2 powder on the carbon microfibers (1416 F g-1vs. 275 F g-1). This improvement in supercapacitor performance can be ascribed to the preservation of the three-dimensional structure of the current collector, which is a fibrous carbon fabric, even after the conformal coating of Ni(OH)2 nanoflakes. The 3-D network morphology of the fibrous carbon fabric leads to more efficient electrolyte penetration into the conformal electrode, allowing the ions to have greater access to active reaction sites. Cyclic stability testing of the conformal and planar Ni(OH)2 nanoflake electrodes, respectively, reveals 34% and 62% drop in specific capacitance after 10 000 cycles. The present study demonstrates the crucial effect that electrolyte penetration plays in determining the pseudocapacitive properties of the supercapacitor electrodes. © 2013 The Royal Society of Chemistry.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: The authors acknowledge Dr Dongkyu Cha, Research Scientist at KAUST Advanced Nano Imaging and Characterization Laboratory (ANIC), for his help in TEM characterization, and Dr Omar El Tall, Research Specialist at KAUST Analytical Core Lab (ACL), for his help in physisorption experiments. Nuha A. Alhebshi acknowledges the support from the KAUST Graduate Fellowship. R. B. Rakhi acknowledges the support from SABIC Postdoctoral Fellowship.
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)