Journal article 38 views 5 downloads
Towards safer electrolytes: comparing the air stability and electrochemical properties of NaPF6, NaTFSI and Na[B(hfip)4]·DME for sodium-ion batteries
,
David J. Morgan ,
Daniel Curtis ,
Marcin Orzech ,
Sajad Kiani ,
Brent de Boode,
Clare P. Grey ,
Dominic S. Wright ,
Serena Margadonna
EES Batteries
Swansea University Authors:
Darren Ould, James Courtney , Daniel Curtis , Marcin Orzech , Sajad Kiani , Serena Margadonna
-
PDF | Version of Record
©2026The Author(s). This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
Download (2.27MB)
DOI (Published version): 10.1039/d6eb00011h
Abstract
Sodium-ion batteries (SIBs) are a promising post lithium-ion battery (LIB) technology, which offer advantages in improved sustainability. This work investigates using NaTFSI [TFSI = bis(trifluoromethylsulfonyl)imide] and Na[B(hfip)4]·DME [hfip = OCH(CF3)2 (OiPrF), DME = 1,2-dimethoxyethane] as alter...
| Published in: | EES Batteries |
|---|---|
| ISSN: | 3033-4071 |
| Published: |
Royal Society of Chemistry (RSC)
2026
|
| Online Access: |
Check full text
|
| URI: | https://cronfa.swan.ac.uk/Record/cronfa71325 |
| Abstract: |
Sodium-ion batteries (SIBs) are a promising post lithium-ion battery (LIB) technology, which offer advantages in improved sustainability. This work investigates using NaTFSI [TFSI = bis(trifluoromethylsulfonyl)imide] and Na[B(hfip)4]·DME [hfip = OCH(CF3)2 (OiPrF), DME = 1,2-dimethoxyethane] as alternative electrolyte salts to the current benchmark standard NaPF6 and compares their air stability, electrochemical properties and performance in sodium-ion coin cells. Multinuclear NMR spectroscopic experiments found that NaPF6 and NaTFSI were stable to atmospheric air after one month, whereas Na[B(hfip)4]·DME showed signs of degradation. The air stability of NaPF6 was compared to LiPF6, where the latter underwent complete decomposition after 24 hours. Electrochemical investigations in 1 M solutions of ethylene carbonate: diethyl carbonate (EC:DEC) solvent revealed 1 M NaPF6 has the highest bulk conductivity. Cyclic voltammetry experiments showed 1 M NaPF6 and 1 M Na[B(hfip)4]·DME are compatible with aluminium foils up to 4.2 V vs. Na/Na+, whereas 1 M NaTFSI underwent aluminium corrosion. Corrosion could be supressed by either limiting cut-off voltage or by the addition of 2 wt% NaPF6 as an additive, both applicable mitigation strategies. Stable long-term cycling at 1C rate in cells using a Prussian white cathode and hard carbon anode occured with both 1 M NaPF6 and 1 M NaTFSI electrolytes. Thus, 1 M NaTFSI is a viable alternative to 1 M NaPF6 in SIBs with a Prussian white cathode, offering a potentially safer electrolyte choice by limiting HF generation on account of the strong C–F bonds in NaTFSI. |
|---|---|
| College: |
Faculty of Science and Engineering |
| Funders: |
Faraday Institution (SPR_100064) |