Designing 2D Janus Zr2CTX MXenes for anode materials in lithium-ion batteries

Abstract

Background:

Recently, 2D MXenes have shown great potential for use as electrode materials in lithium-ion batteries because of their unique layered structures and superior mechanical properties.

Methods:

Density functional theory (DFT) was utilized to explore the potential applications of 2D Janus Zr-based MXenes with various surface atoms, including O, S, Se, and Te, as anode materials in lithium-ion batteries.

Significant Findings:

The results showed that

possesses excellent capacity and mechanical properties except for its non-metallic nature, limiting its application as the anode material. By selectively substituting O on one side of the

surface by Se and Te, resulting in

and

, respectively, the materials exhibit metallic characteristics. Both

and

were found to have high capacities (with values of 370.41 and 317.12 mA h g⁻¹, respectively) and be capable of adsorbing multiple Li layers on both sides. In addition, lower diffusion barriers were found on Se and Te sides compared with the O side. This study demonstrated that the creation of Janus structures enhances the electronic properties of Zr-based MXenes while maintaining their superior mechanical properties, rendering the materials more suitable for use as electrodes in lithium-ion batteries.