Electrochemical Impedance of a Battery Electrode with Anisotropic Active Particles
Author(s)Song, Juhyun; Bazant, Martin Z
MetadataShow full item record
Electrochemical impedance spectra for battery electrodes are usually interpreted using models that assume isotropic active particles, having uniform current density and symmetric diffusivities. While this can be reasonable for amorphous or polycrystalline materials with randomly oriented grains, modern electrode materials increasingly consist of highly anisotropic, single-crystalline, nanoparticles, with different impedance characteristics. In this paper, analytical expressions are derived for the impedance of anisotropic particles with tensorial diffusivities and orientation-dependent surface reaction rates and capacitances. The resulting impedance spectrum contains clear signatures of the anisotropic material properties and aspect ratio, as well as statistical variations in any of these parameters.
DepartmentMassachusetts Institute of Technology. Department of Chemical Engineering; Massachusetts Institute of Technology. Department of Mathematics
Song, Juhyun and Bazant, Martin Z. "Electrochemical Impedance of a Battery Electrode with Anisotropic Active Particles." Electrochimica Acta 131 (June 2014): 214-227 © 2014 Elsevier Ltd