Electrochemical Impedance Imaging via the Distribution of Diffusion Times
Chemical Physics
2018-03-21 v1 Mesoscale and Nanoscale Physics
Abstract
We develop a mathematical framework to analyze electrochemical impedance spectra in terms of a distribution of diffusion times (DDT) for a parallel array of random finite-length Warburg (diffusion) or Gerischer (reaction-diffusion) circuit elements. A robust DDT inversion method is presented based on Complex Nonlinear Least Squares (CNLS) regression with Tikhonov regularization and illustrated for three cases of nanostructured electrodes for energy conversion: (i) a carbon nanotube supercapacitor, (ii) a silicon nanowire Li-ion battery, and (iii) a porous-carbon vanadium flow battery. The results demonstrate the feasibility of non-destructive "impedance imaging" to infer microstructural statistics of random, heterogeneous materials.
Keywords
Cite
@article{arxiv.1709.04147,
title = {Electrochemical Impedance Imaging via the Distribution of Diffusion Times},
author = {Juhyun Song and Martin Z. Bazant},
journal= {arXiv preprint arXiv:1709.04147},
year = {2018}
}