Materials Science

Assessing ternary materials for fluoride-ion batteries



Although lithium‐ion batteries have transformed energy storage, there is a need to develop battery technologies with improved performance. Fluoride‐ion batteries (FIBs) may be promising alternatives in part due to their high theoretical energy density and natural elemental abundance. However, electrode materials for FIBs, particularly cathodes, have not been systematically evaluated, limiting rapid progress. Here, we evaluate ternary fluorides from the Materials Project crystal structure database to identify promising cathode materials for FIBs. Structures are further assessed based on stability and whether fluorination/defluorination occurs without unwanted disproportionation reactions. Properties are presented for pairs of fluorinated/defluorinated materials including theoretical energy densities, cost approximations, and bandgaps. We aim to supply a dataset for extracting property and structural trends of ternary fluoride materials that may aid in the discovery of next‐generation battery materials.


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Supplementary weblinks

Github repository of ternary fluoride cathodes
The repository contains the python script used to create the dataset, as well as the dataset itself. There are three spreadsheets in the dataset. 'ternary_f_cathodes_all.csv' contains all pairs of candidate cathodes, where a 'pair' is the defluorinated and fluorinated versions of each electrode. 'ternary_f_cathodes_direct.csv' contains only those cathode pairs that can be directly converted into each other without any intervening (disproportionation) reactions. 'costdb_elements_new.csv' contains the list of elements (1st column) and costs ($/kg) that are used in our material cost estimates.