DOI: 10.5281/zenodo.15688067
title: Interaction between Formation Protocol and Electrolyte Composition during Solid-Electrolyte Interphase Formation: A Model-Supported Investigation - Dataset

description: Dataset of the publication Interaction between Formation Protocol and Electrolyte Composition during Solid-Electrolyte Interphase Formation: A Model-Supported Investigation published in Journal in Year by Schomburg et al. In the study, an electrolyte and formation variation was conducted using three-electrode cells at 40°C: 4 electrolytes (1M LiPF6 in EC:DEC (1:1, by wt.)+2VC%, 1M LiPF6 in EC:EMC (3:7, by wt.)+2VC%, 1M LiPF6 in EC:DMC (1:1, by wt.)+2VC%, 1M LiPF6 in EC:EMC:DMC (3:2:5, by wt.)+2VC%) were formed with two formation protocols and subsequently electrochemically characterized. More information about the test procedure and used equipment can be found in the publication (DOI).
description: This dataset contains the post-processed data of the cell tests, impedance spectra and half-cell reference curves (Graphite, NMC622). The data is provied as .mat files. The file DB.xlsx provides an overview of the electrolyte and formation protocol used for each test. The cell test data is organized within the archive data_mat. Each subdirectory corresponds to a test and is labeled using the format  ID_Test_<n>, where <n> denotes the test identifier in the DB.xlsx. Within each test folder the impedance and electrochemical test data of the entire test as well as of separate sections is provided:



eis.mat: impedance spectroscopy data @50% SOC

data.mat: complete electrochemical data of the test

data_form.mat: data of the formation (section of data.mat)

data_aging.mat: data of the formation (section of data.mat)

data_capacity.mat: data of the post-formation capacity tests (section of data.mat)

data_pocv1.mat: data of the post-formation pOCV (section of data.mat)

data_pocv2.mat: data of the post-aging pOCV (section of data.mat)

data_puls_ch.mat: data of the charge puls @50% SOC (section of data.mat)

data_puls_dch.mat: data of the discharge puls @50% SOC (section of data.mat)


The impdace data is given as a struct with the fields f (frequence vector) and Z (impedance vector). The electrochemical data of the cycling tests is given as a table, including the voltage (U), current (I), negative electrode potential (Phi_Neg), positive electrode potential (Phi_Pos) as well as derived values, e.g., charge throughput Q0 as a function of the time t.The reference curves for the graphite (pocv_ref_Gr.mat) and NMC622 (pocv_ref_NMC622.mat) electrodes are provided in the archive param. Each reference curve is stored as a struct with the fields int (intercalation) and deint (deintercalation). These fields each contain a nested struct with the variables x (degree of lithiation) and Phi (half-cell potential).

The data_eval_DRT and data_eval_SEI folders contain the evaluation results of the DRT or DVA and ICA of the respective tests.
description: All experiments were conducted using PAT-cells in a three-electrode configuration (EL-Cell GmbH, Hamburg, Germany), which features a lithium reference. As electrodes high-energy (artificial graphite and NMC622) of CustomCells Holding GmbH (Itzehoe, Germany) were used. Available and calculated electrode properties are listed Supprting information of the publication (DOI). As separator a Whatman GF/A glass fiber with a Li|Li+ reference ring was used. For all cells a consistent electrolyte volume of 200µL was used. All electrolytes were purchased from E-Lyte Innovations GmbH (Münster, Germany).

Cell assembly was carried out inside an argon-filled glovebox (GS MEGA E-Line, Malsch, Germany). All electrodes were punched into 18mm diameter discs. Subsequent assembly followed the guidelines of EL-Cell. To ensure uniform wetting of the separator and electrodes, cells were rested for at least 24h prior to electrochemical testing.All electrochemical tests were conducted at 40°C in a KB053-230V climate chamber (Binder GmbH, Tuttlingen, Germany) using a CTS LAB System (BaSyTec GmbH, Asselfingen, Germany). Currents were calculated based on the nominal capacity of 8.9 mAh, calculated using the nominal areal cathode capacity of 3.5 mAh/cm2. The impedance measurements were done with a Zennium Pro (Zahner-Elektrik GmbH & Co. KG, Kronach, Germany) in a frequency range of 10 mHz-100 kHz and a 600 μA (≈1/15 C) amplitude.