LiH as a Li$^+$ and H$^-$ ion provider

TL;DR

This study uses first-principles calculations to analyze native defect formation and migration in lithium hydride, revealing its potential as a source of Li$^+$ and H$^-$ ions relevant for hydrogen storage and batteries.

Contribution

First-principles analysis of defect formation and migration in LiH, highlighting its ionic conductivity and role in energy storage applications.

Findings

Negatively charged lithium vacancy and positively charged hydrogen vacancy are dominant defects.

Defect formation energy is approximately 0.85 eV, indicating ease of ion provision.

Results explain ionic conductivity and hydrogen loss observed experimentally.

Abstract

We present a first-principles study of the formation and migration of native defects in lithium hydride (LiH), a material of interest in hydrogen storage and lithium-ion batteries. We find that the negatively charged lithium vacancy and positively charged hydrogen vacancy are the dominant defects in LiH with a formation energy of about 0.85 eV. With this low energy, LiH can be a good provider of Li$^+$ and/or H$^-$ ions. Based on our results, we discuss the role of LiH in its reactions with another reactant which are important in hydrogen storage and lithium-ion batteries, and explain the ionic conductivity and hydrogen surface loss as observed in experiments.