Using first-principles study on the characteristics of γ-GeSe as anode of sodium-ion battery

Abstract

γ-GeSe is a newly discovered two-dimensional (2D) material with exceptional electrical conductivity, which has generated significant interest in secondary ion battery. In this study, we have used first-principles calculations to evaluate the potential of γ-GeSe as an anode material for sodium-ion batteries. The results show that γ-GeSe has excellent stability properties with in-plane Young’s modulus as high as 30 Gpa and no imaginary frequencies in the phonon band spectrum. Upon adsorption of sodium, γ-GeSe undergoes a semiconductor-to-metal transition, enhancing electron conductivity. Moreover, Ab initio molecular dynamics calculations at room temperature (300 K) revealed the structural stability of γ-GeSe even after 10 ps of Na adsorption. We compute three distinct diffusion paths, with the lowest migration energy barrier of only 0.09 eV, indicating excellent migration rates. The calculated open-circuit voltage of 0.56 V (< 1 V) is crucial for anode material. Furthermore, the maximum theoretical capacity of γ-GeSe is determined to be 442 mAh/g. These findings provide valuable insights into the electrochemical energy storage potential of γ-GeSe as an anode material for sodium-ion battery.