Synergistic influence of charge conditions on electrochemical impedance response of LiNiMnCoO2|C coin cells - Complementary statistical analysis
By Morali, Ugur
Published in Journal of Energy Storage
2020
Abstract
This study focuses on the simultaneous influence of state-of-charge, charge rate, cut-off current and rest period on each element of the equivalent circuit model implemented for the commercially available LiNiMnCoO2|C button cells. The state-of-charge is shown to be the most crucial factor affecting all the equivalent circuit elements; whereas, the rest period is the least effective parameter except for the cathodic diffusion impedance. The response table and the variance analysis show that the cathodic capacitance is the most sensitive response variable. The exponent of the constant phase element is shown to be the most durable response variable to the factor influences. The increasing temperature not only increases the cell reaction kinetics due to reduced charge transfer resistances but also slightly improves capacitance values, whereas the influence on double-layer capacitance could be neglected. The significant factors are determined to ensure and to implement a stable system combined with a charging operation for the lithium-ion batteries to be able to supply the requirements of battery management strategies.