Abstract:For a problem of low performance of planar supercapacitors

graphene films were prepared by a method of direct growth on silicon wafers as electrodes

and PVA/H2SO4 is used as gel electrolyte. Graphenebased all-solidstate planar supercapacitor was prepared with working principle of electric double layer capacitor. The results of cyclic voltammetry showed that the supercapacitor had characteristics of double layer capacitance

and there was no redox peak in the cyclic voltammetry curves

indicating that the electric double layer provided capacity of electrodes. When the scanning rate was 50mV/s

the supercapacitor had better performance of cyclic voltammetry. The area capacitance was 290.24μFc-2 and the energy density was 22.68μWhcm-2. This paper provides an important reference for further research on planar micro-supercapacitors.