Diglyme based electrolytes for sodium-ion batteries
Artikel i vetenskaplig tidskrift, 2018

Sodium-ion batteries (SIBs) are currently being considered for large-scale energy storage. Optimization of SIB electrolytes is, however, still largely lacking. Here we exhaustively evaluate NaPF6 in diglyme as an electrolyte of choice, via both physicochemical properties and extensive electrochemical tests including half as well as full cells. Fundamentally, the ionic conductivity is found to be quite comparable to carbonate based electrolytes and to obey the fractional Walden rule with viscosity. We find Na metal to work well as a reference electrode and the electrochemical stability, evaluated potentiostatically for various electrodes and corroborated by DFT calculations, to be satisfactory in the entire voltage range 0-4.4 V. Galvanostatic cycling at C/10 of half and full cells using Na3V2(PO4)(3) (NVP) or Na3V2(PO4)(2)F-3 (NVPF) as cathodes and hard carbon (HC) as anodes indicates rapid capacity fading in cells with HC anodes, possibly originating in a lack of a stable SEI or by trapping of sodium. Aiming to understand this capacity fade further, we conducted a GC/MS analysis to determine electrolyte reduction products and to propose reduction pathways, concluding that oligomer and/or alkoxide formation is possible. Overall, the promising results should warrant further investigations of diglyme based electrolytes for modern SIB development, albeit avoiding HC anodes.

degradation

sodium-ion

batteries

stability

electrolytes

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Publicerad i

ACS Applied Energy Materials

25740962 (eISSN)

Vol. 1 Nummer/häfte 6 s. 2671-2680

Forskningsprojekt

Nästa generation batterier för hybrid- och elfordon

Energimyndigheten (37671-1), 2013-12-01 -- 2017-12-31.

Na-Ion bAttery Demonstration for Electric Storage (NAIADES)

Europeiska kommissionen (EU) (EC/H2020/646433), 2015-01-01 -- 2018-12-31.

Kategorisering

Drivkrafter

Hållbar utveckling

Styrkeområden

Transport

Energi

Materialvetenskap

Ämneskategorier (SSIF 2011)

Fysik

Annan fysik

Kemi

Infrastruktur

C3SE (-2020, Chalmers Centre for Computational Science and Engineering)

Chalmers materialanalyslaboratorium

Identifikatorer

DOI

10.1021/acsaem.8b00360

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Senast uppdaterat

2025-03-09