Issue 27, 2024

In-depth exploration of the effect mechanisms of various lithium salt anions in solid-state and liquid lithium metal batteries

Abstract

Lithium salts exert a great influence on the electrochemical performance of lithium metal batteries. Dissociated Li-ions present rapid transfer dynamics through solvation with a solvent in liquid batteries or complexation–decomplexation with a polymer in solid batteries. However, the effect of the anion on the properties of batteries is still unclear. Herein, lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) and lithium difluoro(oxalato)borate (LiDFOB) are selected to investigate the working mechanism of anions in solid and liquid systems. LiTFSI demonstrates superior electrochemical performance in solid batteries (stable cycling for 2000 h at 0.1 mA cm−2), while LiDFOB exhibits better cycling performance in liquid batteries (the capacity retention reaches 94.8% after 500 cycles at 1C). DFT calculations are conducted to investigate the discrepancy and suggest that TFSI presents higher binding energy with PEO, indirectly proving the important role of the anion in facilitating the transfer of Li-ions in solid systems. As for liquid batteries, XPS and in situ optical microscope analyses show that DFOB is conducive to the generation of robust interfaces and inhibits the continuous decomposition of the electrolyte. Therefore, it can be innovatively deduced that the properties of solid batteries are determined by Li-ion transfer adjusted by the anion, while the liquid battery performance is decided by the electrode/electrolyte interface stability regulated by the anion.

Graphical abstract: In-depth exploration of the effect mechanisms of various lithium salt anions in solid-state and liquid lithium metal batteries

Supplementary files

Article information

Article type
Paper
Submitted
22 mars 2024
Accepted
02 juin 2024
First published
03 juin 2024

J. Mater. Chem. A, 2024,12, 16447-16456

In-depth exploration of the effect mechanisms of various lithium salt anions in solid-state and liquid lithium metal batteries

Y. Pan, H. Yu, Y. Zhang, Z. Wang, S. Wang, C. Li, Y. Ma, X. Shi, H. Zhang, D. Song and L. Zhang, J. Mater. Chem. A, 2024, 12, 16447 DOI: 10.1039/D4TA01939C

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