Open AccessDynamic Electrochemical Impedance Spectroscopy of Lithium-ion Batteries: Revealing Underlying Physics through Efficient Joint Time-Frequency Modeling
Author(s) -
Linnette Teo,
Venkat R. Subramanian,
Daniel T. Schwartz
Publication year - 2021
Publication title -
journal of the electrochemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.258
H-Index - 271
eISSN - 1945-7111
pISSN - 0013-4651
DOI - 10.1149/1945-7111/abda04
Subject(s) - dielectric spectroscopy , electrical impedance , time domain , lithium cobalt oxide , frequency domain , materials science , chemistry , analytical chemistry (journal) , control theory (sociology) , electronic engineering , electrode , physics , battery (electricity) , electrical engineering , lithium ion battery , computer science , electrochemistry , engineering , mathematics , mathematical analysis , power (physics) , control (management) , quantum mechanics , chromatography , artificial intelligence , computer vision
The value and interpretation of dynamic electrochemical impedance spectroscopy (DEIS) during the charging and discharging of lithium-ion batteries is examined using the Doyle-Fuller-Newman pseudo-two-dimensional (P2D) lithium-ion battery model with parameters for a lithium-cobalt-oxide/graphite cell. Two computational approaches are explored to balance accuracy, speed, and interpretability: (i) A brute force time domain calculation of the full nonlinear equation set subject to direct current (DC) plus superimposed sinusoidal modulation of frequency ω 1 , followed by post-processing with short-time Fourier transforms to track the dynamic impedance signal at the modulation frequency during charge and discharge; (ii) A fast-computing time-separated method that solves the C-rate dependent P2D equations for the DC charge/discharge transients occurring on the slow time-scales, t b ∼ O(3600 s/C), followed by solutions to linearized frequency domain equations derived for direct computation of the dynamic impedance signal. The time-separated method is rigorously correct in the limit 1/( t b ω 1 ) → 0. Key physics that drives differences between stationary and dynamic EIS signals is easily explored with the time-separated method. C-rate dependent studies show that DEIS signals are selectively sensitive to interfacial processes in ways that may be promising for real-time diagnostics and control of the negative electrode at high states-of-charge (SOC) and the positive electrode at low SOCs.