A halogen-free and flame-retardant sodium electrolyte compatible with hard carbon anodes

DOI: 10.1002/admi.202101135

Authors: Lars Olow Simon Colbin (Uppsala University) , Ronnie Mogensen (Uppsala University) , Alexander Buckel (Uppsala University) , Yong‐lei Wang (Stockholm University) , Andrew J. Naylor (Uppsala University) , Jolla Kullgren (Uppsala University) , Reza Younesi (Uppsala University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Advanced Materials Interfaces

State: Published (Approved)
Published: October 2021
Diamond Proposal Number(s): 26551

Abstract: For sodium-ion batteries, two pressing issues concerning electrolytes are flammability and compatibility with hard carbon anode materials. Non-flammable electrolytes that are sufficiently stable against hard carbon have—to the authors’ knowledge—previously only been obtained by either the use of high salt concentrations or additives. Herein, the authors present a simple, fluorine-free, and flame-retardant electrolyte which is compatible with hard carbon: 0.38 m sodium bis(oxalato)borate (NaBOB) in triethyl phosphate (TEP). A variety of techniques are employed to characterize the physical properties of the electrolyte, and to evaluate the electrochemical performance in full-cell sodium-ion batteries. The results reveal that the conductivity is sufficient for battery operation, no significant self-discharge occurs, and a satisfactory passivation is enabled by the electrolyte. In fact, a mean discharge capacity of 107 ± 4 mAh g−1 is achieved at the 1005th cycle, using Prussian white cathodes and hard carbon anodes. Hence, the studied electrolyte is a promising candidate for use in sodium-ion batteries.

Journal Keywords: NaBOB; non-flammable electrolytes; organophosphate; sodium bis(oxalato)borate; sodium-ion batteries; triethyl phosphate (TEP)

Diamond Keywords: Batteries; Sodium-ion

Subject Areas: Materials, Chemistry, Energy


Instruments: I09-Surface and Interface Structural Analysis

Added On: 25/10/2021 11:54

Documents:
admi.202101135.pdf

Discipline Tags:

Physical Chemistry Energy Energy Storage Materials Science Energy Materials Physics Surfaces Chemistry

Technical Tags:

Spectroscopy X-ray Photoelectron Spectroscopy (XPS)