Electrode batches

The "Public label" column in metadata.csv describes the chemical composition and manufacturing route of each electrode batch. Each electrode is cycled between voltage cutoffs:

Cycling Programmes

The "Cycling Programme name" column in metadata.csvdescribes the electrochemical protocols to determine the half-cell OCV of active materials. All protocols were set to run for 5 cycles and at room temperature.

Usage Notes

Data processing

• The electrochemical time series have been processed from their original format to the Battery Data Format (BDF) promoted by the Battery Data Alliance (Linux Foundation). 
• Processing into BDF involved simple transformations of dates format, units and column labels. No additional cleaning or imputation has been performed.
• The datasets are compressed in Apache parquet format from their original size, and readily usable with traditional Python data analysis packages such as Pandas and Polars. 
• The electrochemical time series report cumulative capacities. These can be divided by the "Mass of Active Material" reported in metadata.csv to obtain specific capacities.

Materials 

• OCVs from Si-containing electrodes might exhibit large variations depending on material properties, such as particle size, crystallinity, surface chemistry, percentage of silicon in Si-Graphite blends, etc. None of these material and electrode properties are available from the suppliers. Therefore these OCVs in the dataset should not be considered as representative for all Si-containing electrodes.
• The OCVs from LiNi0.5Mn1.5O4 (LNMO) electrodes vary depending on the degree of Mn/Ni disorder (see Sun et al.). The LNMO material used in this study targeted high Mn/Ni disorder, therefore the OCVs is a highly disordered spinel

Known issues

All electrochemical time series were plotted to visually inspect for prominent issues during cycling. Cells that were completely unable to cycle were replaced with new measurements when possible. Cells that failed after few cycles or exhibited anomalies were kept in the published dataset; below we list the known issues, also described in the "Knwon Issues" column in metadata.csv:

Versions

V1

Original submission.

V2

Corrected the cycling programme of a data file. The test was incorrectly logged as a GITT with hold test, but visual inspection of the time series revealed it was instead a GITT test without voltage hold. Both the file name and in the metadata.csv have been now updated with the correct cycling proggramme; from:

V3 

• Corrected a typo in the units of electrode diameter (from cm to mm) in metadata.csv.
• Updated electrode masses and weight percentages of active materials for commericial electrodes LFP, NMC111 and NMC532, after reaching out to electrode manufacturers who provided the information:
  • NMC532: Percentage weight of active material [%] and mass loading of active material [g/cm2].
  • NMC111 Percentage weight of active material [%]. The mass of electrode coating was calculated by substracting the mass of blank current collectors from the mass of coated electrodes.
  • LFP: Percentage weight of active material [%]. The mass of electrode coating was calculated by substracting the mass of blank current collectors from the mass of coated electrodes.
• Now that active material massess are reported, the subsection "Unavailable metadata" in the Usage Notes have been removed. The subsection "Data Processing" has been updated to point users to the now complete active material massess to obtain specific capacities.