Theoretical investigation of halides encapsulated Na@B 40 nanocages for potential applications as anodes for sodium ion batteries

The increasing demand of energy storage materials has attracted considerable attention of scientific community towards the development of rechargeable ion batteries (RIBs). Herein, B40 nanoclusters are theoretically analyzed for their potential application as anode material for sodium-ion batteries. DFT calculations are per-formed for geometrical and electrochemical properties study of Na or Na+ adsorbed A-@B40 (A= F-, Cland Br-) complexes. Na+ and Na adsorbed preferably on R7 and R6 positions of boron nanocage (B40), respectively, where the interaction of Na+ is stronger in comparison to Na atom. The change in Gibbs free energy (cell potential) values of R7-B40 and R6-B40 complexes (of bare case) are-11.21 kcal mol-1 (0.49 V) and-8.92 kcal mol-1 (0.39 V), respectively. For further improvement of change in Delta G and Vcell values, halides are encapsulated (A = F-, Cland Br-) into boron nanocage. The Vcell of Na-ion batteries for R7-A@B40 and R6-A@ B40 (A = F-, Cland Br-) increases up to 3.594 V and 3.492 V, respectively. These results illustrate that the electrochemical properties of A@B40 nanocage explicitly depend on the nature of alkali metals and their respective halide ions.

Automated summary

The study theoretically analyzed the potential application of B40 nanoclusters as anode materials for sodium-ion batteries, finding that Na+ adsorbs stronger than Na on the boron nanocage. Encapsulating halides into the boron nanocage improved the performance of the Na-ion batteries.