Issue 11, 2021

Non-flammable liquid electrolytes for safe batteries


With continual increments in energy density gradually boosting the performance of rechargeable alkali metal ion (e.g. Li+, Na+, K+) batteries, their safe operation is of growing importance and needs to be considered during their development. This is essential, given the high-profile incidents involving battery fires as portrayed by the media. Such hazardous events result from exothermic chemical reactions occurring between the flammable electrolyte and the electrode material under abusive operating conditions. Some classes of non-flammable organic liquid electrolytes have shown potential towards safer batteries with minimal detrimental effect on cycling and, in some cases, even enhanced performance. This article reviews the state-of-the-art in non-flammable liquid electrolytes for Li-, Na- and K-ion batteries. It provides the reader with an overview of carbonate, ether and phosphate-based organic electrolytes, co-solvated electrolytes and electrolytes with flame-retardant additives as well as highly concentrated and locally highly concentrated electrolytes, ionic liquids and inorganic electrolytes. Furthermore, the functionality and purpose of the components present in typical non-flammable mixtures are discussed. Moreover, many non-flammable liquid electrolytes are shown to offer improved cycling stability and rate capability compared to conventional flammable liquid electrolytes.

Graphical abstract: Non-flammable liquid electrolytes for safe batteries

Article information

Article type
Review Article
09 May 2021
15 Sep 2021
First published
16 Sep 2021
This article is Open Access
Creative Commons BY license

Mater. Horiz., 2021,8, 2913-2928

Non-flammable liquid electrolytes for safe batteries

R. Gond, W. van Ekeren, R. Mogensen, A. J. Naylor and R. Younesi, Mater. Horiz., 2021, 8, 2913 DOI: 10.1039/D1MH00748C

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