The role of Ru doping on the electronic, mechanical and vibrational properties of Li₂MnO₃ cathode material

Abstract

We present a comprehensive first-principles study of Ru-doped Li2MnO3 cathode material for lithium-ion batteries, utilising hybrid density functional calculations. Ru was chosen due to its ability to enhance cycling stability and structural integrity. The investigated structures, adapted from a previous study and generated through cluster expansion, include Li 2 RuO 3 , Li 2 Mn 0.33 Ru 0.6 7O 3 , and Li 2 Mn 0.5 Ru 0.5 O 3 , which are compared with the pristine material. The primary properties under investigation include the density of states, phonon dispersion curves, and elastic properties. The analysis of the density of states reveals that Li 2 Mn 0.33 Ru 0.67 O 3 and Li 2 RuO 3 exhibit metallic magnetism, while Li 2 Mn 0.5 Ru 0.5 O 3 behaves as a semiconductor with a narrower band gap than Li 2 MnO 3 . Ru doping in Li 2 MnO 3 narrows the bandgap, enhancing conductivity and structural integrity, which is expected to improve lithium-ion battery performance.