Transport Phenomena Commons^™

Electrochemical And Mechanical Evaluation Of Cellulose Acetate Electrolyte Films As A Function Of Polyetherimide And Polyethylene Glycol Additives For Supercapacitor Applications, Chase E. Golden

Chemical Engineering Undergraduate Honors Theses

Polymer electrolytes for supercapacitor applications require a balance between mechanical robustness and electrochemical performance. In this study, cellulose acetate (CA) films were modified with additives such as polyetherimide (PEI) and polyethylene glycol (PEG) to test how compositional changes influence mechanical performance, ionic conductivity, and electrochemical charge storage. Films were cast using phase inversion, soaked in a 1 M NaCl aqueous solution, and characterized using Fourier-transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and tensile testing. Films were also evaluated based on fluid uptake for insight into electrolyte retention.

Characterizations show that the addition of PEI increased ionic …

Short-Time Transient Analysis Of Intercalation Of An Ion Into A Sphere, Sheba Devan, Ralph E. White

Faculty Publications

A short-time transient analysis is presented for a sinusoidal input potential for a spherical particle. The objective of this work was to extract accurate values of the parameters associated with an intercalation into a spherical particle. These parameters are exchange current density, double-layer capacitance, and diffusion coefficient. The effects of these parameters on the response were examined using a sensitivity analysis, which indicated that optimum frequency values of the input perturbation exist for estimation of these parameters. A procedure is presented to obtain all these parameters using the short-time response. The results show that the short-time analysis is a useful …

Transient Analysis Of A Porous Electrode, Sheba Devan, Venkat R. Subramanian, Ralph E. White

Faculty Publications

An analytical expression is presented for the voltage response including the transient voltage for a simple (i.e., no concentration gradients) porous electrode model subject to a sinusoidal input current density. The transient voltage response as a function of the frequency, exchange current density, and double layer capacitance is studied independent of the periodic (steady state) voltage response. The change in the voltage response in the transient region is compared to that of the periodic voltage response with respect to the parameters. The physical properties of the porous electrode can be estimated using the voltage response in the transient …