# Dynamics of Li-ion in V2O5 Layers from First-Principles Calculations

## TL;DR

This study uses first-principles calculations to explore Li-ion diffusion in V2O5 layers, revealing one-dimensional diffusion pathways linked to unstable phonon modes, which could inform better battery electrode designs.

## Contribution

It demonstrates the connection between unstable phonon modes and Li-ion diffusion pathways in V2O5 using ab-initio methods, a novel insight for battery material research.

## Key findings

- Li-ion diffusion is one-dimensional along the b-axis.
- Unstable phonon modes correlate with diffusion pathways.
- Diffusion observed at high temperature (1200 K) in simulations.

## Abstract

The alkali atoms, due to their small sizes and low charge ionic states, are most eligible to intercalate in the structural layers of V2O5. We have applied ab-initio density functional theory to study the dynamics of Li-ion in layers of {\alpha}-V2O5. The calculations are performed for two compositions, namely, Li0.08V2O5 and Li0.16V2O5, and show that there are unstable phonon frequencies. The unstable modes have large amplitude of Li atom along the b-axis of the orthorhombic unit cell indicating that such unstable modes could initiate Li-ion diffusion along b-axis. The ab-initio molecular dynamics simulations are performed up to 25 ps at 1200 K, which reveal one-dimensional diffusion of Li atoms. The diffusion pathways of Li atoms from the simulations seem to follow the eigenvectors of the unstable phonon modes obtained in the intercalated structure.

---
Source: https://tomesphere.com/paper/1904.00681