Detection of Lithium?Ion Cells’ Degradation through Deconvolution of Electrochemical Impedance Spectroscopy with Distribution of Relaxation Time

Herein, a methodology to investigate aging of commercial cylindrical Li-ion cells is introduced. Distribution relaxation time (DRT) method applied deconvolute electrochemical impedance spectroscopy (EIS) measurements and separate those polarization effects that are usually overlapped in the frequency domain by means peak-based representation. Half-cells built at beginning end life link processes occurring anode and/or cathode sides. Moreover, lab-made full-cells exploited verify reproducibility when compared with cells. The results an extensive analysis around 500 EIS spectra return unambiguous attribution different constants ultimately DRT peaks. Digital imaging validates graphite degradation, mainly related lithium plating. Scanning electron microscopy degradation NMC cathode, attributed particle cracking. It concluded peaks allow characterize cell their tracking can help develop more reliable state health estimators.