Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7728399 | Journal of Power Sources | 2016 | 8 Pages |
Abstract
The impedance of a commercial lithium ion cell (2 Ah) is evaluated over a wide frequency range of 10-5 Hz < f < 102 Hz using a new approach. The so-called pulse-fitting method (PFM) derives the cell impedance from time domain measurements, which are transferred into frequency data by a using a newly developed evaluation algorithm in combination with the distribution of relaxation times (DRT). The time constants of the individual polarization processes taking place during charging/discharging were analyzed at 20 different state-of-charge levels at 23 °C in a wide frequency range spanning from 10-5 Hz < f < 102 Hz. The pulse-fitting method seems to be especially useful for monitoring the change of individual polarization losses in the course of time, as self-discharge effects can be sorted out.
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Jan Philipp Schmidt, Ellen Ivers-Tiffée,