Material design of high-capacity Li-rich layered-oxide electrodes: Li2MnO3 and beyond

Abstract

Lithium-ion batteries (LIBs) have been used widely in portable electronics, and hybrid-electric and all-electric vehicles for many years. However, there is a growing need to develop new cathode materials that will provide higher cell energy densities for advanced applications. Several candidates, including Li₂MnO₃-stabilized LiM′O₂ (M′ = Mn/Ni/Co) structures, Li₂Ru_0.75Sn_0.25O₃ (i.e., 3Li₂RuO₃–Li₂SnO₃), and disordered Li₂MoO₃–LiCrO₂ compounds can yield capacities exceeding 200 mA h g⁻¹, alluding to the constructive role that Li₂MO₃ (M⁴⁺) end-member compounds play in the electrochemistry of these systems. Here, we catalog the family of Li₂MO₃ compounds as active cathodes or inactive stabilizing agents using high-throughput density functional theory (HT-DFT). With an exhaustive search based on design rules that include phase stability, cell potential, resistance to oxygen evolution, and metal migration, we predict a number of new Li₂M_IO₃–Li₂M_IIO₃ active/inactive electrode pairs, in which M_I and M_II are transition- or post-transition metal ions, that can be tested experimentally for high-energy-density LIBs.