Rickard Andersson; Amin M. Saleem; Ioanna Savva; Theodora Krasia-Christoforou; Peter Enoksson; Vincent Desmaris
Abstract
Carbon nanostructures are of great interest for a variety of applications, but their current processing throughput limits their industrial full scale deployment. This paper presents a cost effective and simple fabrication process, where vertically aligned carbon nanofibers are grown using DC-PECVD at ...
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Carbon nanostructures are of great interest for a variety of applications, but their current processing throughput limits their industrial full scale deployment. This paper presents a cost effective and simple fabrication process, where vertically aligned carbon nanofibers are grown using DC-PECVD at CMOS compatible temperatures from catalytic nanoparticles, spin-coated from stable polymer-nanoparticle colloidal suspensions. Two different catalysts, Co and Cu, are investigated by growing carbon nanofibers at temperatures ranging from 390°C to 550°C, using suspensions with various concentrations of nanoparticles. The length and morphology of the grown nanofibers are examined using SEM and the electrical properties are investigated using electrochemical measurements on samples arranged as supercapacitor devices. Vertically aligned CNFs are successfully grown from both types of catalyst. The Co-derived fibers are long and arranged in a denser carpet-like structure, while the Cu-derived fibers are shorter and in a sparser formation of free-standing individual fibers. All electrochemical measurements show typical supercapacitor behaviour even at high scan rates of 200 mVs -1 , with the fibers grown from Co showing great increase in capacitance over the bare chip reference device, including the samples grown at 390°C.
Anna Batlle
Abstract
Wearable devices requires from macroscopic mechanical properties laying in macro-scale in comparison with chemical processes that requires from material design in the nanoscale. Besides, such reactions and phenomena involves charge transfer, and therefore a charge transducer in mean scale is required. ...
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Wearable devices requires from macroscopic mechanical properties laying in macro-scale in comparison with chemical processes that requires from material design in the nanoscale. Besides, such reactions and phenomena involves charge transfer, and therefore a charge transducer in mean scale is required. In this paper we propose a flexible and wearable supercapacitor that takes advantage of a conductive fabric current collector that is coated by electrospray with MnO2-decorated carbon nanofibers (CNF). The results point out that a high capacitance is obtained due to the pseudocapacitive reactions in MnO2; moreover, the long and conductive structure of CNF allow transferring charge to conductive fabric, keeping a low equivalent serial resistance (ESR). The results indicate a specific capacitance on fabric collector of (226.40 ± 0.3) F/g, about 10 times higher than on aluminum foil collector, with a similar ESR which indicates a suitable way to wearable devices. The proposed technique is scalable, and can be easily applied in the industry.
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