Graphene based sulfonated polyvinyl alcohol hydrogel nanocomposite for flexible supercapacitors

Abstract

Graphene based sulfonated polyvinyl alcohol (PVA) hydrogel was synthesized and its performance as nanocomposite gel polymer electrolyte was investigated for application in quasi solid-state flexible supercapacitors. Hydrothermally reduced graphene (HRG) was synthesized through hydrothermal reduction of graphene oxide (GO). Sulfonated PVA hydrogel (SPVA) was synthesized with predetermined quantities of HRG to obtain nanocomposite gel polymer electrolytes coded as SPVA-HRG-x (x = content (wt.%) of HRG). The amorphous nature of SPVA-HRG-x was determined using X-ray diffraction (XRD) technique. The electrochemical performance of SPVA-HRG-x was evaluated using techniques like cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical spectroscopy (EIS) studies of a lab scale supercapacitor cell, fabricated using hydrothermally reduced carbon cloth (CCHy) current collectors coated with HRG (HRG-CCHy). In SPVA-HRG-0.5 electrolyte, HRG-CCHy exhibited specific capacitance of 200 F g-1 at 1 A g-1 and specific energy of 6.1 Wh kg-1 at specific power of 1 kW kg-1 and retained 93 % of its initial capacitance even after 5000 GCD cycles. The incorporation of SPVA with 0.5 wt.% of HRG-CCHy can be attributed to the increase in amorphous nature of SPVA-HRG-0.5, which in-turn lowers its impedance. This contributed to the remarkable supercapacitive behaviour of HRG-CCHy, demonstrating its potential as gel polymer electrolyte (GPE) for application in quasi solid-state flexible supercapacitors.

Rice husk char as a potential electrode material for supercapacitors

“…Obtained HRG was vacuum dried (12 h at 60 °C) and ground to fine powder. HRG (0.5 wt.%) incorporated sulfonated PVA (SPVA-HRG-0.5) hydrogel electrolyte was prepared by synthesis procedure reported elsewhere [40]. PVA (0.5 g) was added to a mixture of DI water (4 mL) and H2SO4 (270 µL) and stirred continuously for half an hour at 80 °C to obtain sulfonated PVA hydrogel (SPVA).…”

Challenges and doubts of electrochemical energy conversion and storage

“…Razvoj različitih materijala, pogotovo od sredine 20. veka i pronalaska elektrohemijkih dvojnoslojnih superkondenzatora čiju osnovu čine ugljenični materijali, doveo je do toga da danas postoje čitav niz supekondenzatora raličitih osobina [24]. Posebno treba izdvojiti pseudokapacitivne superkondenzatore, koji koriste neke okside metala ili provodne polimere koji pored akumulacije naelektrisanja na površini, deo energije akumuliraju i isporučuju procesima Faradejske prirode, razmenjuju elektrone kroz niz diskretnih stanja,elektrohemijskom reakcijom.…”

Char of Tagetes erecta (African marigold) flower as a potential electrode material for supercapacitors

“…NGPE was prepared by incorporating HRG into sulfonated PVA hydrogel to obtain HRG incorporated sulfonated PVA hydrogel (SPVA-HRG-0.5) following the procedure reported elsewhere [48]. To DI water (4 mL), H2SO4 (270 L) was added and heated up to 80 °C followed by the addition of PVA (0.5 g) and stirred until a clear sulfonated PVA (SPVA) hydrogel was obtained.…”