LIXS Spectral Data for Fluorine Calibration and Spatial F/Li Mapping of Li-Ion Battery Cathodes

This repository contains the experimental data underlying the research work “Spatial Heterogeneity of the Fluorine-to-Lithium Intensity Ratio as a Descriptor of Battery Degradation and Failure by Laser-Induced XUV Spectroscopy.”

Laser-induced XUV spectroscopy (LIXS) was used to investigate fluorine, lithium, and cobalt in composite Li-ion battery cathodes. The dataset supports the matrix-matched calibration of fluorine in different lithium metal oxide materials and the spatially resolved comparison of pristine, formed, aged, and failed lithium cobalt oxide (LCO) cathodes.

The archive is organized into two groups:

· Calibration

This group contains 21 CSV files corresponding to seven cathode chemistries (NMC111, NMC442, NMC532, NMC622, NMC811, LCO, and LMO) prepared at three fluorine levels. Each file contains a wavelength axis and 49 individual LIXS spectra acquired on a 7 × 7 measurement grid. A PDF file with the elemental mass composition of the cathodes is provided.

· Cells (maps)

This group contains spatially resolved LIXS data (maps) for four LCO cathode states:

o   pristine: as-prepared cathode not assembled into a cell;

o   formed: cathode recovered after the initial formation procedure without subsequent cycling;

o   aged: cathode recovered after 100 cycles at 1C;

o   failed: cathode recovered after rapid performance loss over 30 cycles.

Each CSV file contains the wavelength axis and 289 spectra acquired on a 17 × 17 raster.

All spectral files contain 2048 wavelength points covering approximately 3.48-20.67 nm. The intensity columns correspond to individual laser-ablation positions and retain the spatial coordinates in their file headers. The spectra were exported to CSV after averaging the detector image across its non-dispersive dimension.

The dataset can be used to reproduce the calibration plots, spatial intensity maps, radial profiles, boxplots, kernel density estimates, and F/Li ratio analysis reported in the associated manuscript. It may also support alternative spectral processing, calibration, chemometric, or multivariate approaches for LIXS data from battery materials.