Computational screening of anode materials for potassium-ion batteries

Potassium ion batteries (PIBs) are promising alternatives to Li-ion batteries due to the abundance of potassium. However, the development of PIBs is in its early stages, and only a few anode materials have been reported. Herein, we explored anode materials for PIBs using high-throughput computational screening. The alloying and conversion reactions of prospective anode materials were investigated using the Materials Project database. Grand potential diagrams were obtained to examine the reaction potential and theoretical capacity of the anode materials. Calculation results indicated that P, As, Si, and Sb anodes exhibited high theoretical capacities. In addition, the screening results revealed that phosphides generally exhibit a lower reaction potential compared with those of sulfides and oxides. A total of 18 binary compounds that exhibited a high theoretical capacity and a low reaction potential (greater than 450 mAh/g and 0.7 V) were identified as promising anode materials for PIBs. In particular, ZnP2, CuP2, SiP, NiP3, CoP3, V3S4, Nb3S5, Bi2O3, and Ga2O3 exhibited high theoretical capacities.