A DFT + U-D3 Study of the Adsorption of Hydrogen Fluoride and Ethylene Carbonate on the Niobium-Doped (001), (011), and (111) Surfaces of Lithium Manganese Oxide

Abstract

Cationic doping has played an important role in the improvement and development of more efficient cathode materials for secondary lithium-ion batteries. In lithium manganese oxides, it was recommended as one of the most effective methods of reducing the number of trivalent manganese (Mn 3+) ions that undergo disproportionation reaction. In the quest to meet the increasing demand for cheap, renewable, and clean energy, an in-depth understanding of surface doping and the reactivity towards the electrolyte is crucial. Here, we present a detailed DFT study of the effect of Nb doping on the major (001), (011), and (111) LiMn 2 O 4 surfaces and their interactions with the electrolyte components, ethylene carbonate (EC), and hydrogen fluoride (HF). Our calculations show that Nb doping in the sub-surface layers greatly enhances the (111) plane in the morphology, which is of significant interest since it has been reported in the literature that the exposed (111) surface promotes the development of stable solid electrolyte interface which can reduce Mn dissolution. Introducing the EC/HF on the Nb second surfaces further enhances the expression of the (111) surface.

Materials modelling in the University of Limpopo

“…The MMC has applied some of the world-leading simulation approaches to produce such nanostructures in Li-ion batteries [39,40] and first principles methods [41], which shed valuable insights on precursor reactor processes occurring in laboratories, industrial pilot and production plants. It has also applied machine learning cluster expansion methods to determine the stability of doped NMC cathodes [42] and has carried out surface calculations for cathodes [43] and metal air batteries [44,45].…”