Computational study of novel 2H chromium ditelluride as an anode material for Li/K-ion batteries

Abstract

The goal of metal-ion battery research is to develop anode materials with high storage capacity. This study explored the potential of 2H phase CrTe₂, composed of two hexagonally stacked layers, as an optimal anode material for Li/K-ion batteries using Density Functional Theory (DFT). Preliminary analyses revealed that the material possesses thermodynamic, structural, and mechanical stability. A key finding was the significantly negative adsorption energy, which enhances battery stability by preventing clustering and stabilizing Li/K adsorption on the material's surface. The adsorption energy values for Li/K were calculated to be −3.7 eV and −4.63 eV, respectively. These results suggest stable lithiation and potassiation processes, with maximum storage capacities of 1395 mA h g⁻¹ for Li and 1134 mA h g⁻¹ for K. Additionally, the calculated open-circuit voltages (OCVs) for CrTe₂ were 0.13 V for K-ions and 0.20 V for Li-ions. We calculated the adsorption energy, structural and electronic properties, theoretical capacity, diffusion energy, and thermal stability. The electrical conductivity of the material increased, and its metallic properties were maintained with increasing metal-ion concentration. This study highlights the potential of CrTe₂ as a novel anode material for Li-/K-ion batteries.