Impedance analysis with ELSA and DRT for various electrochemical and electrical systems

Dataset of the analysis of various electrochemical and electrical systems with Electrochemical System Analysis (ELSA) and Distribution of Relaxation Times method (DRT). For full explanation see publication: [[ Electrochemical System Analysis – from impedance data to system identification ]]

The impedance dataset used is available at Zenodo for download: doi:10.5281/zenodo.10794584. A detailed information about the systems and the properties of the spectrum can be found there. The following systems were analyzed:

Lithium-Ion battery LFP (A123 26650)

Lithium-Ion battery NCR (Panasonic 18650)

Vanadium redox-flow Battery
Polymer electrolyte membrane fuel cell

High-temperature PEM (Custom made)

Double-layer capacitor 3.4 kF (Maxwell)

Analogue RLC circuit (Custom made)

Details
A123 Systems, 26650 lithium iron phosphate | graphite, 2,5 Ah
Panasonic NCR-18650B, 18650 nickel-manganese-cobalt-oxid | graphite, 2.5 Ah
Micro Flow Cell (Electrocell A/S, Tarm, DK), surface 10 cm2 
ElringKlinger(EK) single PEM fuel cell, active surface area 50 cm2 
Custom made fuel cell assembly, metallic bipolar plates with single serpentine flow-fields, electrode surface area of 4 cm², polybenzimidazole (PBI) membranes (Dapazol1, Danish Power Systems-DPS1) 
Maxwell, capacitance 3400 F, 2.85 V
Custom made circuit with a parallel connection of a 2.2 μF foil capacitor and a lossy inductor with 9.7 mΩ  and 5 mH, factory values may vary ± 10 %

The data is available as .json and as .mat to allow easy import in different programming languages. Please note, that complex data in the .json files are converted to strings and thus need to be converted after importing.

Naming convention:

[[name of system]]_[[rxx (xx = model order for special cases)]]_[[method]]

method: drt, elsa, elsa_simulation (simulated impedance data)

Data structure:

_meta: metadata for software package used_class: classname for class usedconfig: configuration for the analysisdata: input data used for the analysisSpecific to ELSA:- system: Here, all calculated systems (including zeros, poles, gain, partial fraction decomposition, ...) for every step are saved- impedance: Simulated impedance and residuals for all systemsSpecific to DRT:- drt: Result of DRT calcualtion (including h, h_rc, h_rl, r_0, l_0, c_0, lambda, l_curve, ...)- optimization: Matrices of the linear optimization problem- simulation: Simulated impedance and residuals for calculated DRT