Electrochemical impedance spectroscopy (EIS) is a versatile characterization and diagnostic technique widely used in electrochemistry applications to study batteries , fuel cells , solar cells , electrolyzers , and beyond . The distribution of relaxation times (DRT) has recently emerged as a promising non-parametric approach to analyze impedance spectra and has been applied to identify electrode processes , estimate battery state-of-health , and assess the performance of fuel cells . Furthermore, the DRT has been used to develop equivalent circuit models without requiring prior circuit architecture information . The DRT approach models the impedance, 𝑍 DRT (𝑓, 𝝍), at frequency, 𝑓 , and an experimental state, 𝝍 , as 𝑍 DRT (𝑓, 𝝍) = 𝑖2𝜋𝑓𝐿 0 (𝝍) + 𝑅 ∞ (𝝍) + ∫ 𝛾(log 𝜏 , 𝝍)