The development of cost-effective and efficient energy-storage devices

such as supercapacitors with enhanced electrochemical properties

is highly needed for the future. Therefore

the highly porous surface area of wheat straw

which is activated carbon (AC) derived through chemical activation

is being used to develop electrodes. AC with a surface area of 1093.46 m2/g was used for electrode fabrication by mixing proportions of 80%

90%

100%

and 0% AC with polyvinylidene fluoride and N-methyl-2-pyrrolidone solution on different current collectors such as copper

stainless steel

and aluminum. The electrochemical analysis of the developed electrodes and symmetric electrochemical double-layer capacitors was performed against a silver/silver chloride reference electrode by using cyclic voltammetry

galvanostatic charge–discharge

and electrochemical impedance spectroscopy. The specific capacitance of the electrodes

as shown in cyclic voltammogram curves

is 305.2

287

and 256.2 F/g. The galvanostatic charge–discharge curves display 281

244.5

and 226.5 F/g at 0.5 A/g

and 247

206

and 189 F/g at 1 A/g for copper

aluminum

and stainless steel current collectors

respectively. The symmetric electrochemical double-layer capacitors

made with 90% AC and copper current collectors

exhibited quasi-rectangular curves with specific capacitances of 219.4

172.7

and 132.4 F/g. Different areas of the current collector in supercapacitors increase the active material deposit

enabling more charge and ions to accumulate

resulting in improved charge-transfer resistance.