Electrochemical Impedance Spectroscopy (EIS) is an advanced technique characterizing the dynamics of an electrochemical process through small voltage or current perturbation. It measures the dielectric response of the cell to the perturbation in a wide frequency range. By building appropriate circuit model and fitting it to the EIS results. Many information like the solvent resistance, charge transfer resistance and leak capacitance can be extracted and further analyzed. Other than EIS, the SP-300 electrochemistry work station in the lab also offers Cyclic Voltammetry, Galvanic Charging Discharging and Ragone Plot for characterization.
The Nanomaterials and Thin Film Lab studies carbon nanotube and other carbon based materials, including the synthesis, characterization and electrochemical application. We are using EIS to characterize the charge transfer resistance of g-CNT (Figure 1), CNT neural electrode (Figure 2) and various kinds of supercapacitor like CNT supercap and Cu-Ni Nanowire supercap. Our recent effort has focused on flexible and highly stretchable crumpled CNT supercapacitor, CNT/TiN neural electrode with Pt precursor and 4D printed graphene supercapacitor.
Stoner, BR; Raut, AS; Brown, B; Parker, CB; Glass, JT(2011)."Graphenated carbon nanotubes for enhanced electrochemical double layer capacitor performance" Applied Physics Letters.99(18) More info
Ubnoske, SM; Raut, AS; Brown, B; Parker, CB; Stoner, BR; Glass, JT(2014)."Perspectives on the Growth of High Edge Density Carbon Nanostructures: Transitions from Vertically Oriented Graphene Nanosheets to Graphenated Carbon Nanotubes." The Journal of Physical Chemistry C.118(29): 16126- 16132 More info
Brown, B; Parker, CB; Stoner, BR; Grill, WM; Glass, JT(2012)."Electrochemical charge storage properties of vertically aligned carbon nanotube films: Effects of thermal oxidation" The Journal of Physical Chemistry C.116(36): 19526- 19534 More info