Graphite/copper nanoparticle-based high-performance micro supercapacitor with porous wet paper-based PVA-PVP blend polymer electrolyte

A 2D supercapacitor with graphite/copper nanoparticle electrodes and a PVA-PVP polymer electrolyte was screen printed. A novel method to deposit the electrolyte on the current collectors using a porous wet paper has been described to overcome several disadvantages of conventional solid-state gel electrolytes. SEM imaging showed the ideal size of deep pores in the paper-based medium which assisted the electrolyte in storing charge and facilitated high conductivity and capacitance. Electrochemical analysis via Cyclic Voltammetry at various scan rates showed a specific capacitance of 24.12 F g⁻¹. Cyclic stability and charge-discharge times were studied via galvanostatic charge-discharge cycles. The excellent flexibility of the device has been demonstrated by plotting the absolute and relative resistance change across the Cu electrodes at different bending angles with the maximum relative resistance change shown to be less than 5%.