This work proposes a method to combine time-domain and frequency-domain measurement data for parameterization of RC elements by exploiting the full potential of the distribution of relaxation times (DRT).
Modeling capacity fade of li-ion batteries
Aging models are fundamental tools to optimize the application of lithium-ion batteries. In this work, we show that the CAP-method models capacity fade more accurately when applied to dynamic cyclic aging tests with periodically changing mean state-of-charge, depth-of-discharge, ambient temperature and discharge rates for a commercial NCA cell with a silicon-doped graphite anode.
Quantifiability of Cell-to-Cell Variations
Motivated by the question of why impedance variation is consistently reported to be higher than the variation of other parameters, we show that measuring inherent parameter variations caused by production tolerances is superimposed by effects of an imperfect measurement setup.
Impedance Research Paper
Continuous impedance monitoring provides significant insights into the aging status of a battery. However, the on-line determination of battery impedance parameter for its low-frequency part is a challenging task. This paper provides an algorithm for its determination, which features a novel approach to quantifying the impedance caused by diffusion processes at low frequencies.