# Exploring the Impact of Electric Field and OLi3 Decoration on Inorganic Graphenylene SiC for Reversible Hydrogen Storage: A First-Principles Investigation

## TL;DR

This study investigates how decorating a silicon carbide material with OLi3 and applying an electric field can improve hydrogen storage capacity and efficiency.

## Contribution

The novel contribution is demonstrating that OLi3 decoration and electric fields can enhance hydrogen storage and reversibility in inorganic graphenylene SiC.

## Key findings

- OLi3 decoration on IGP-SiC achieves a hydrogen storage capacity of 10.93 wt %, exceeding the DOE target.
- Applying an electric field increases hydrogen adsorption energy from −0.197 to −0.657 eV/H2.
- Hydrogen diffusion energy barrier is low at 0.054 eV, indicating good reversibility.

## Abstract

The hydrogen storage
capacity of superalkali OLi3-decorated
inorganic graphenylene SiC (IGP-SiC) has been explored using first-principles
calculations employing the GGA-PBE functional. Notably, OLi3 is found to be strongly bonded to the IGP-SiC monolayer with a binding
energy of −3.89 eV. Thus, a positive charge is developed on
the lithium atom of OLi3 due to charge redistribution,
which enhances its hydrogen adsorption energy. The interaction of
H2 with OLi3@IGP-SiC involves charge polarization
as well as orbital and van der Waals interactions. Our calculations
reveal a remarkable hydrogen storage capacity of 10.93 wt %, surpassing
the DOE-recommended limit of 6.5 wt %, where the hydrogen adsorption
energy is found to be in the range of −0.19 to −0.15
eV/H2. To assess the thermal stability and reversibility
of hydrogen storage exhibited by OLi3@IGP-SiC, ab initio
molecular dynamics (AIMD) simulations were performed at temperatures
of 100, 200, and 300 K. Hydrogen adsorption energy (E
H2

ad) of OLi3@IGP-SiC can be tuned by applying an electric
field. It is noticed that E
H2

ad in OLi3@IGP-SiC
+ 1H2 is increased from −0.197 eV/H2 (at
zero electric field) to −0.657 eV/H2 upon application
of a +0.055 V/Å electric field. Furthermore, by employing the
climbing-image nudged elastic band method, the hydrogen diffusion
energy barrier is found to be 0.054 eV. Therefore, the OLi3-decorated IGP-SiC monolayer designed in this study may serve as
a potential reversible hydrogen storage material.