Investigation of nanopore scale composition changes during the charge and discharge of supercapacitors

Supercapacitors are emergent electrochemical energy storage devices that exhibit very high power densities. The absence of experimental confirmation of the structure of the electrochemical double layer limits our understanding of these devices. In this research, we propose to measure the total scattering data on NIMROD using a commissioned electrochemical cell designed for NIMROD. The supercapacitor will consist of activated carbon electrodes and 1M tetraethylammonium tetrafluoroborate in acetonitrile electrolyte. We will observe the change in the SANS feature that arises from the porous structure of the carbon as either the deuterated electrolyte or solvent moves through it. By utilising both the SANS and total scattering data, we will measure the relative concentration of each species in the bulk and pores at various states of charging to obtain an insight into the behaviour of both solvent and electrolyte during the formation of the electrochemical double layer.