Symmetric supercapacitors based on porous 3D interconnected carbon framework

Abstract

The construction and design of novel porous carbons for electric double-layer capacitors (EDLCs) application to meet the increasing demand and supply of energy is eminent. This is important because the pore volume (PV)/micropore volume (MV) in the porous network architecture of the carbon is mostly responsible for the ion traps in energy storage. Three dimensional carbon materials based on graphene materials with relatively high specific surface area (SSA) represents a promising material candidate for EDLCs applications. In this work, we synthesized highly porous carbon from graphene foam (GF) and polyvinyl alcohol PVA as a sacrificial template, and investigate their performance as electrodes for EDLCs applications. The as-produced carbons present a fairly large surface area (502 m 2 g -1 ), and a highly porous interconnected framework with mesopore walls and micropore texture which are suitable as electrode for energy storage. As electrode material in a symmetric configuration the activated graphene foam (AGF) showed a specific capacitance of 65 F g -1 , energy density of 12 Wh kg -1 , power density of 0.4 kW kg -1 , good rate performance and excellent long term stability in 1 M Na 2 SO 4 aqueous with no capacitance loss after 3000cycles.

Stability studies of polypyrole- derived carbon based symmetric supercapacitor via potentiostatic floating test

“…Thus, the symmetric cell was subjected to floating at 1.2 V at 5 A g -1 in order to determine the stability of the electrodes on the cycle life and how long 16 it takes before the electrodes begin to degrade. A 10 h voltage holding period is trailed by five CCCD cycles to detect any loss in the cell capacitance over 190 h. Fig.…”

“…For example symmetric supercapacitor operating at 1.6 V in neutral 1 M and 0.5 mol L −1 Na 2 SO 4 media were reported [16,17]. [14,19,20].…”

Microwave synthesis: Characterization and electrochemical properties of amorphous activated carbon-MnO2 nanocomposite electrodes

“…Activated carbon materials were prepared using a method in our previous work [28,29]. The AC-MnO x composites were prepared using both solvothermal (Ethylene glycol (EG) and water) and hydrothermal (water) routes with microwave irradiation.…”

Investigation of different aqueous electrolytes on the electrochemical performance of activated carbon-based supercapacitors

“…However, organic and ionic liquids are plagued with some demerits which include high cost, low conductivity (large internal resistance), generally complicated handling procedures involved, high ammability and electrolyte leakage. 27 In contrast, aqueous electrolytes have lower cost, environmentally friendly nature, facile preparation methods and operating stability, high ionic conductivity and proton transport which is necessary for obtaining lower internal resistance. 28 It is worthy to state that even though aqueous electrolytes are characterized with a limited operating voltage in comparison with organic electrolytes, the ions present in the former are still capable of much faster transport rates in relation to the latter.…”