Towards flexible and wearable supercapacitors: A hierarchical approach in material design

¹Department of Engineering: Electronics. IN2UB, Universitat de Barcelona, Martí i Franquès 1, Barcelona, 08028, Spain

²EUSS: Escola Universitaria Salesiana de Sarria, Passeig de Sant Joan Bosco, 74, Barcelona, 08017, Spain

Adv. Mater. Lett., 2017, 8 (12), pp 1145-1149

DOI: 10.5185/amlett.2017.1680

Publication Date (Web): Sep 08, 2017

Copyright © IAAM-VBRI Press

E-mail: acirera@ub.edu

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. 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. 

Keywords

Supercapacitor, fabric, CNF, MnO₂, electrospray.