Electrochemical responses of flexible graphite in H$_2$SO$_4$

Abstract

Asymmetric capacitors are gaining attention due to their hybrid nature with higher power and energy density compared to individual batteries or capacitors. Electrochemical and structural characteristics of flexible graphite in 40% H$_{2}$SO$_{4\, }$electrolyte are investigated using electrochemical and microscopy techniques. There is a correlation between intercalation of electrolyte and the enlargement of interlayer spacing and electrochemical response. Conditions favoring planar orientation are electrochemically less active and more stable in such corrosive electrolytes. There are response variations between plain and resin-impregnated flexible graphite samples. The reaction peak seems to be reversible for resin impregnated samples while plain samples show continuous intercalation. The higher positive potential limit in cyclic voltammetry causes peak potential to increase in orders of magnitudes.