High-capacity hydrogen storage by metallized graphene

TL;DR

This paper predicts that lithium-adsorbed graphene can serve as a high-capacity hydrogen storage medium, with each lithium atom capable of binding four hydrogen molecules, significantly enhancing graphene's storage potential.

Contribution

It introduces a novel high-capacity hydrogen storage method using lithium-covered graphene, supported by first-principles calculations showing stable Li adsorption and effective H2 binding.

Findings

Li can be stably adsorbed on graphene forming a uniform coverage

Li-covered graphene can absorb up to four H2 molecules per Li atom

The gravimetric density of hydrogen storage reaches 12.8 wt%

Abstract

First-principles plane wave calculations predict that Li can be adsorbed on graphene forming a uniform and stable coverage on both sides. A significant part of the electronic charge of the Li-$2s$ orbital is donated to graphene and is accommodated by its distorted $\pi^*$-bands. As a result, semimetallic graphene and semiconducting graphene ribbons change into good metals. It is even more remarkable that Li covered graphene can serve as a high-capacity hydrogen storage medium with each adsorbed Li absorbing up to four H$_2$ molecules amounting to a gravimetric density of 12.8 wt%.