Systematically Evaluation of the Cathodic Performance of Crobr with Vacancies and Partial Substitutions on Surface for Metal Batteries

Abstract

CrOBr has been reported to have significant advantages in terms of kinetics and thermal stability. At present, relevant computational studies have been conducted on layered CrOBr, but the maximum utilization advantage based on the adsorption characteristics of metal atoms on the surface of CrOBr has not been reported. When improving material performance, the first thing to consider is to adjust the overall regulation of adsorption structure and electronic structure, specifically by substituting and creating vacancies. In engineering, the above surface structural diversity can be easily achieved through chemical etching and laser ablation techniques. Since the first principles have obvious advantages in evaluation, here, considering homologous substitution and vacancies, density functional theory (DFT) are performed to reflect the potential of CrOBr as cathode material via calculating electronic structures and interaction characteristics between metal atoms and the substrate electrode. Especially, mixed cationic electrolytes can also be examined, the atoms (Li, Na, Mg and Al) of some common metal batteries are discussed. Indicators such as atom absorption energy, diffusion energy barriers, band/density of states (DOS) structures, and open circuit voltage curves (OCV) are calculated in detail. This general strategy for evaluating and improving cathode material CrOBr is also applicable to other general electrodes.

Keywords: Transition metal oxyhalides, CrOBr Cathode material, open circuit voltage, metal diffusion barriers