Evaluation of Sb/Bi heterostructure as anode material for Li/Na/K-ion intercalation batteries: A DFT study

Abstract

The Sb/Bi heterostructure, a central focus in advanced metal-ion (AM) battery research, stands out for its substantial surface area and impressive capacity. Using density functional theory, we identify it as a highly promising anode material for lithium-, sodium-, and potassium-ion batteries. Our calculations demonstrate stable adherence of Li, Na, and K atoms to the Sb/Bi surface, with adsorption energies of −1.71 eV, −1.92 eV, and −2.4 eV, respectively, indicating favorable stability during the lithiation, sodiation, and potassiation processes. Incorporating Sb/Bi in electrodes displays exceptional conductivity, resulting in a lower anode voltage and good capacity. Theoretical capacities are 2106, 88.63, and 113.95 mAh/g for Li, Na, and K batteries. Notably, the Sb/Bi heterostructure exhibits thermal stability and metallic behavior. Open circuit voltage (OCV) values recorded for Li, Na, and K ions on the Sb/Bi heterostructure are 0.14 V, 0.20 V, and 0.17 V, respectively. Hirschfeld charge analysis provides insights into charge distribution, contributing to the understanding of Sb/Bi electrochemical behavior. This study highlights the potential of Sb/Bi heterojunctions, offering improved electrochemical performance and innovative pathways for experimental synthesis in the realm of advanced metal-ion batteries.