Dataset for: The topographic origin of chemomechanical failure in high-nickel cathodes revealed by operando dark-field X-ray microscopy

This repository contains the processed operando Dark-Field X-ray Microscopy (DFXM) maps and electrochemical data required to reproduce the analysis in the paper "The topographic origin of chemomechanical failure in high-nickel cathodes revealed by operando dark-field X-ray microscopy" (2026). The dataset captures the intragranular lattice evolution of single-crystal NMC 811 primary particles during their first electrochemical formation cycle, specifically targeting the moment of dislocation nucleation at a surface notch (3.9 V). Data Contents: The dataset is organized into spatially resolved diffraction maps and corresponding electrochemical logs: 1. Operando DFXM Maps (.h5) Spatially resolved diffraction maps for single-crystal NMC 811 particles at critical states of charge (3.6 V, 3.9 V, 4.4 V): *_COM_mu.h5: Center-of-Mass (COM) Lattice Tilt Maps. Represents the projected lattice orientation (mu) used to calculate lattice curvature and GND density. *_mosaicity.h5: Strain-Spread Correlation Maps. High-dimensional maps encoding the full 3D orientation vector (Hue = Orientation, Saturation = Mosaicity). *_kurtosis.h5: Peak Kurtosis Maps. Statistical 4th moment maps used to quantify sub-pixel lattice decoherence and disorder. *_control.h5: Spherical Control Particle. Validation data for a defect-free particle cycled to high voltage (4.4 V). 2. Finite Element Modelling (.mat) Simulation results defining the geometric failure thresholds: *_crack.mat: Von Mises stress and plastic strain fields for Shallow, Medium, and Deep surface defects. 3. Electrochemistry (.mpr) NMC811_Operando_Echem.mpr: Raw BioLogic electrochemical data (Time, Voltage, Current) enabling the synchronization of X-ray frames with the charge profile. Analysis Code: The Python notebooks for visualizing, quantifying, and reproducing the figures from this data are available on GitHub: https://github.com/BASE-Laboratory/DFXM-Topographic-Origins Methodology: Data was collected at ESRF Beamline ID03 under experiment number MA-6506. Raw 3D reciprocal space diffraction volumes were reduced to 2D projection maps using Darfix and the custom reduction workflow described in the main manuscript. License: Creative Commons Attribution 4.0 International