A literature-derived dataset of migration barriers for quantifying ionic transport in battery materials

Abstract

The rate performance of any electrode or solid electrolyte material used in a battery is critically dependent on the migration barrier ($E_m$) governing the motion of the intercalant ion, which is a difficult-to-estimate quantity both experimentally and computationally. The foundation for constructing and validating accurate machine learning (ML) models that are capable of predicting $E_m$, and hence accelerating the discovery of novel electrodes and solid electrolytes, lies in the availability of high-quality dataset(s) containing $E_m$. Addressing this critical requirement, we present a comprehensive dataset comprising 619 distinct literature-reported $E_m$ values calculated using density functional theory based nudged elastic band computations, across 443 compositions and 27 structural groups consisting of various compounds that have been explored as electrodes or solid electrolytes in batteries. Our dataset includes compositions that correspond to fully charged and/or discharged states of electrode materials, with intermediate compositions incorporated in select instances. Crucially, for each compound, our dataset provides structural information, including the initial and final positions of the migrating ion, along with its corresponding $E_m$ in easy-to-use .xlsx and JSON formats. We envision our dataset to be a highly useful resource for the scientific community, facilitating the development of advanced ML models that can predict $E_m$ precisely and accelerate materials discovery.

Figures (3)

• Figure 1: Flowchart illustrating the structural data generation process for each data point in the database. GS refers to ground state. Relax refers to the structural relaxation calculation done with DFT.
• Figure 2: Contour plot illustrating the distribution of the $E_m$ dataset over different space groups from each of the seven crystal systems. Individual colored sectors represent individual crystal systems, with space groups indicated by text notations. White circles indicate invidual data points. Concentric circles correspond to different E$_m$ values (in eV), as highlighted by the blue text notations.
• Figure 3: Illustration of the $E_m$ distribution within each of the different structural groups. The y axis on the left and right represent the number of datapoints and $E_m$ values (in eV), respectively. Stacked bar charts correspond to the counts within each structural group, with the colors indicating the split across various intercalants. The black vertical lines represent the range of $E_m$ values for a given structural group with the squares and circles representing the maxima and minima, respectively. The inset shows a pie-chart with the contributions from each intercalant (i.e., Al, Ca, K, Li, Mg, Na, Rb, Sr, and Zn, as represented by the different colors) to the total dataset.