Issue 17, 2018

An ab initio study for probing iodization reactions on metallic anode surfaces of Li–I2 batteries

Abstract

Lithium–iodine (Li–I2) batteries are considered a competitive candidate for next-generation electrochemical energy storage devices. The high solubility of I2 in aprotic solvents or aqueous solvent systems and the resulting shuttle effect can lead to the corrosion of metallic Li anodes. The present study employs atomistic scale modeling approaches to understand the interactions between Li surfaces and iodine species. It is found that the metallic Li (100) surface and Li (110) surface are very active to capture I2 molecules and facilitate the dissociation of these molecules. According to the ab initio molecular dynamics simulation, the iodization behavior is dependent on the coverage. When the iodine coverage is only 12.5%, the dissociated I atoms will not destroy the anode surface. As the coverage increases to 100%, a thin LiI layer forms but can be exfoliated from the Li surface, resulting in the irreversible loss of active materials. If the coverage is as high as 200%, a thick LiI film can form on the Li anode and deposit on the Li substrate. How the LiNO3 additive protects the Li–I2 battery anode is also studied in the present work. It is found that O and N atoms from the decomposition of the nitrate diffuse faster than I atoms in the metallic anode. Therefore, a Li oxynitride layer can form between the metallic Li metal and the iodine-containing species, which can cut off the direct interaction between the anode and I2 molecules.

Graphical abstract: An ab initio study for probing iodization reactions on metallic anode surfaces of Li–I2 batteries

Supplementary files

Article information

Article type
Paper
Submitted
11 Jan 2018
Accepted
29 Mar 2018
First published
29 Mar 2018

J. Mater. Chem. A, 2018,6, 7807-7814

An ab initio study for probing iodization reactions on metallic anode surfaces of Li–I2 batteries

Z. Liu, W. Hu, F. Gao and H. Deng, J. Mater. Chem. A, 2018, 6, 7807 DOI: 10.1039/C8TA00356D

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements