Equivalent Circuit Model and Parameter Identification of Lithium-Sulfur Battery

To mitigate the intricacies and theoretical vagueness involved in constructing an electrochemical model for lithium-sulfur batteries, as well as the arduousness of parameter identification, which inadequately reflects the battery's dynamic characteristics, this study developed an equivalent circuit model comprising a first-order and a second-order RC circuit based on the impedance spectrum features of lithium-sulfur batteries at different charge levels. Additionally, we established an experimental setup for gathering data for lithium-sulfur battery parameter identification and verified the efficacy and precision of both models and real-time identification methods through simulation and experimental findings. Results evinced that both equivalent circuit models performed proficiently with respect to constant current discharge of lithium-sulfur batteries, with the second-order RC model error amounting to 1% or lower.