Nanocomposites and nanomaterials

Reduced graphene oxide based symmetric supercapacitors
Okhay O.1, Tkach O.2, Staiti P.3, Lufrano F.3
1TEMA-Center for Mechanical Technology and Automation, Department of Mechanical Engineering, University of Aveiro, 3810-193 Aveiro, Portugal 
E-mail: olena@ua.pt 
2CICECO – Aveiro Institute of Materials, Deptartament of Materials and Ceramic Engineering, University of Aveiro, Campus de Santiago, 3810-193, Aveiro, Portugal. 
3CNR-ITAE, Istituto di Tecnologie Avanzate per l'Energia “Nicola Giordano”, 98126 S. Lucia, Messina, Italy.

Development of flexible energy storage devices with high performance is very important due to need to develop next-generation wearable and flexible electronics [1]. Supercapacitors (SCs) are the most promising candidate in comparison to batteries and fuel cells due to their relatively simple structures and inherent electrochemical properties. High-performance SCs need to show high energy and power density, fast charge-discharge and long cycle life. Investigation of flexible electrodes with high capacitance and high electrical conductivity ensures fast charge-discharge. 
Freestanding reduced graphene oxide (rGO) electrodes without binder and composite electrodes with nanospacer and polymer, screen printed on substrates were used for the fabrication and comparison of symmetric SCs here. Freeze dried aerogel of graphene oxide (GO), after heat treatment at two different temperatures and mixing with carbon nanotubes (CNTs) and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF), was used to obtain flexible electrodes on carbon cloth. Symmetric SC based on analyzed composite electrodes shows high durability at 1.6 V and higher specific capacitance.

1.	González A., Goikolea E., Barrena J. A., Mysyk R. Review on supercapacitors: Technologies and materials // Renew. Sust. Energ. Rev.- 2016.-58.-1189.