Atomistic Modelling of High-Entropy Layered Anodes and Their Electrolyte Interface

TL;DR

This study uses computational methods to explore high-entropy layered heterostructures as promising anode materials for Li-ion batteries, showing potential for enhanced electrochemical properties.

Contribution

It introduces high-entropy layered heterostructures as a novel approach to improve anode performance in Li-ion batteries through computational analysis.

Findings

High-entropy TSS heterostructures may offer better electrochemical stability.

Structural deformation is reduced in high-entropy variants.

Enhanced Li-ion diffusion and electron mobility are observed.

Abstract

Van der Waals (vdW) heterostructures have attracted intense interest worldwide as they offer several routes to design materials with novel features and wide-ranging applications. Unfortunately, at present, vdW heterostructures are restricted to a small number of stackable layers, due to the weak vdW forces holding adjacent layers together. In this work, we report on computational studies of a bulk vdW material consisting of alternating TiS2 and TiSe2 (TSS) vertically arranged layers as a potential candidate for anode applications. We use density functional theory (DFT) calculations and ab-initio molecular dynamics (AIMD) simulations to explore the effect of high entropy on several electrochemically relevant properties of the bulk heterostructure (TSS-HS) by substituting Mo6+ and Al3+ at the transition metal site (Ti4+). We also study the solvation shell formation at the electrode-electrolyte interface (EEI) using AIMD to determine Li-coordination. Based on the properties computed using DFT and AIMD we propose that high entropy TSS-HS (TSS-HE) might possess improved electrochemical performance over standard TSS-HS. Factors that could improve the performance of TSS-HE are 1) Less structural deformation, 2) Strong bonding (Metal-Oxygen), 3) Better electron mobility, 4) Wider operational voltage window, and 5) Faster Li-ion diffusion. Our observations suggest that 'high entropy' can be an effective strategy to design new anode materials for improving electrochemical performance of Li-ion batteries.