Computational screening of anode materials for sodium-ion batteries

Sodium-ion batteries are promising candidates for large scale stationary energy storage systems because of the low cost of Na. However, commercialized graphite anodes used in Li-ion batteries are not suitable for Na-ion batteries and the systematic exploration of anode materials remains challenging. In this study, high-throughput screening was performed to identify promising anode materials for use in Na-ion batteries. Alloying and conversion reactions of anode materials were examined using the Materials Project database. The calculations indicated that phosphides exhibited a favorable combination of high theoretical capacity and low reaction potential compared to oxides and sulfides. The computational screening results identified 44 promising anode materials with a high capacity (>500 mAh/g) and low reaction potential (<0.7 V). In particular, six phosphides, CaP₃, CrP₂, NiP₂, VP₂, CoP₂, and GaP, exhibited high theoretical capacities of ∼1000 mAh/g with low reaction potentials of ∼0.3 V.