Theoretical predictions of alkali hexazirconate (A2Zr6O13, A = Li, Na, And K) as candidates for alkali ion batteries†

Abstract

As the demand for advanced energy storage materials continues to grow, it is essential to conduct new research to discover alternative materials for use in batteries. Therefore, this work delves into the potential of new materials for use as alternative electrodes for Li-ion and alkali ion batteries, specifically alkali hexazirconates such as A₂Zr₆O₁₃ (where A represents Li, Na, and K). Utilizing advanced atomistics simulations, our objective is to conduct a comprehensive assessment of their structural, electronic, and mechanical properties. The results indicate the insulating behavior of A₂Zr₆O₁₃ materials, with calculated lattice parameters closely aligned with previous studies. Mechanical property analysis reveals greater susceptibility of Li₂Zr₆O₁₃ and Na₂Zr₆O₁₃ to compression along the x and y axes than along the z-axis. Furthermore, their ductile behavior and Young's modulus, in alignment with lithium and sodium hexazirconates, suggests their potential in alkaline ion batteries. Electrochemical performance shows Li₂Zr₆O₁₃ and Na₂Zr₆O₁₃ present two stable phases during charge and discharge, leading to a plateau in the open cell voltage profile at 1.3 and 2.9 V and theoretical capacity of 69.68 mA h g⁻¹ and 66.89 mA h g⁻¹, respectively. Comparative analysis unearths distinctions in mechanical and electronic properties among Li, Na, and K variants, aiding in the precise tailoring of materials. In conclusion, this study emphasizes the potential of alkali hexazirconates such as A₂Zr₆O₁₃as alternative electrode materials, showcasing notable mechanical stability and derived properties rendering them promising candidates for advancements in energy storage applications.