Unveiling the potential of BCN-Biphenylene monolayer as a high-performance anode material for alkali metal ion batteries: A first-principles study

TL;DR

This study uses first-principles calculations to demonstrate that BCN biphenylene monolayers are stable, exhibit excellent electrochemical properties, and could serve as high-performance anode materials for alkali metal ion batteries.

Contribution

It introduces a new stable BCN biphenylene monolayer with promising electrochemical properties for battery applications, expanding the potential of 2D materials.

Findings

Low ion diffusion activation barriers for Li, Na, and K.

High theoretical capacities exceeding commercial graphite.

Suitable voltage range for alkali metal ion batteries.

Abstract

Inspired by a freshly synthesized two-dimensional biphenylene carbon network, which features a captivating combination of hexagonal, square, and octagonal rings, we explored a similar biphenylene network composed of boron, carbon, and nitrogen (bpn-BCN) using first-principles calculations. There are six possible phases of borocarbonitrides, which are isoelectronic to biphenylene carbon networks with a stoichiometric ratio of 1:1:1 for boron (B), carbon (C), and nitrogen (N) atoms. All possible isoelectronic structures of the BCN combination of biphenylene networks are found to be stable, according to first-principles calculations. Furthermore, we employed first-principles calculations to investigate the electrochemical properties of the most stable geometry of BCN biphenylene as a potential anode material for alkali metal (AM) ion batteries. The electronic properties of the stable phase of bpn-BCN reveal its narrow bandgap semiconductor nature. The ion diffusion calculations show a low activation barrier for Li, Na, and K of 0.65 eV, 0.26 eV, and 0.23 eV, respectively, indicating a fast charge/discharge rate. Furthermore, the theoretical capacities of the BCN biphenylene monolayer for Li (1057.33 mAh/g), Na (647.27 mAh/g), and K (465.98 mAh/g) are found to be greater than those of commercial graphite. The average open-circuit voltage for AM decreases with increasing metal ion concentrations. It falls within a reasonable range of 0.34 to 1.89 V. Our results show that the BCN biphenylene monolayer could be a promising anode material in alkali metal ion rechargeable batteries.