Versatile instrumentation for electrochemical supercapacitor characterization
Abstract
Electrochemical methods such as impedance spectroscopy and cyclic voltammetry are capable of providing insights into electrochemical supercapacitors. This work reports a custom-made measurement device that can run these electrochemical tests using general hardware and Labview software. The device is very low cost yet demonstrates good measurement results compared with commercially available devices. Based on impedance spectroscopy tests, an electrical analog with physical meaning was proposed. The results exhibit good agreement with that obtained through cyclic voltammetry. Impedance spectroscopy was also applied to determine double-layer capacitance, from which pseudo-capacitance can be evaluated. The instrument functioned well for commercially available supercapacitors as well as a custom-made carbon-cloth manganese oxide (CC-MnO 2) electrode. Electrochemically active surface area therefore can be estimated once the pseudo-capacitance was determined. This work also used impedance spectroscopy to assess the CC-MnO2 electrode before and after cycling, and instead of degradation in performance, the sample showed increased capacitance and decreased resistance after 5000 cycles.
Degree
M.S.M.E.
Advisors
Fisher, Purdue University.
Subject Area
Electrical engineering|Nanoscience|Energy
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