Irida-like boron nitride two-dimensional monolayer high-capacity anode for potassium ion battery

Abstract

The focus of the scientific communities is increasingly directed towards clean energy storage and the exploration of alternatives to the detrimental effects associated with traditional K-based batteries. In this context, due to the plentiful availability of potassium resources, potassium-ion batteries (KIBs) have gained attention in recent years. By performing DFT estimations, the current work computationally examined the capacity of irida-like boron nitride allotrope (ID-BN), characterized by its metallicity and a structure composed of three-, six-, and eight-membered C rings, for potassium storage. The maximum potassium capacity of ID-BN was found to be 26 atoms, corresponding to a ratio of 1 potassium atom, with adhesion energies ranging from −1.033 eV for a single potassium atom to −0.189 eV for 26 potassium atoms, indicating robust electrochemical stableness. An analysis of potassium mobility revealed a high diffusion rate of 1.94 × 10⁻⁹ cm²/s at 300 K, accompanied by a minimal diffusion barrier of 0.158 eV. The operating OCV ranged from 0.189 to 0.732 V, making it suitable for safe applications in batteries. Ultimately, the potassium storage capacity was measured at 1157.5 mAhg⁻¹, exceeding that of numerous commercial anodic nanomaterials and is competitive with other structural alternatives. These findings underscore the potential of Ir-BN as an encouraging and safe anodic nanomaterial for KIBs.