Na Battery Electrolytes Prepared by Dissolution of Commercial Polymers in NaPF 6 –Diglyme

The incorporation of small amounts of polymers into liquid electrolytes to produce gel electrolytes has many benefits. Decreasing, or even avoiding flow reduces accidents caused by leaks, allows for simpler and more flexible geometries and configurations, stabilizes electrochemical cycling, and may...

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Detalles Bibliográficos
Autores: Campo, Ángela, García, Nuria, López-Cudero, Ana, Hall, Aram, Younesi, Reza, Tiemblo, Pilar
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2026
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:dnet:digitalcsic_::1090dd7eddbb60be34c21c8ae23061fc
Acceso en línea:http://hdl.handle.net/10261/429898
Access Level:acceso abierto
Palabra clave:Na battery
solid electrolyte
NaPF6
diglyme
polymer gel electrolytes
electrochemical stability
Prussian white cathode
hard carbon
Descripción
Sumario:The incorporation of small amounts of polymers into liquid electrolytes to produce gel electrolytes has many benefits. Decreasing, or even avoiding flow reduces accidents caused by leaks, allows for simpler and more flexible geometries and configurations, stabilizes electrochemical cycling, and may even permit the separate recycling of each cell component. Direct mixing of polymers with liquid electrolytes is very frequently possible, and it is a sustainable and scalable procedure that avoids evaporation stages and produces thermoreversible materials. In this work, some of the polymers most commonly used for gel electrolyte formation─polyvinylidene fluoride (PVDF), polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP), polyvinyl chloride (PVC), poly(methyl methacrylate) (PMMA), and poly(ethylene oxide) (PEO)─are employed to produce gels with the electrolyte NaPF6 1.1 m in diglyme, and their behavior and performance are described. All these polymers are soluble in the electrolyte, and the ultrahigh molecular weight (UHMW) PEO and the halogenated polymers are able to form self-standing gels at concentrations ranging from 5 to 10 wt %. The fluorinated polymer gels left standing in an Ar glovebox progressively become colored, turning almost black after one month, showing a lack of long-term chemical stability. PVC 10 wt % and UHMW PEO 5 wt % gels, however, become hard gels with no macroscopic phase separation and remain stable for periods of months. Their electrochemical stability against Na electrodes was tested, showing that the PVC gel is not stable, and only the UHMW PEO 5 wt % gels were further tested with Prussian white (PW) cathodes. The PEO gel electrolyte, without any physical separator, showed equivalent performance in PW||Na half-cells as the baseline electrolyte with a glass fiber separator, while also being self-standing and solid-like in consistency. The PEO gel electrolytes also showed applicability to PW||HC full cells. Moreover, after electrochemical testing, the coin cells with PEO gels were easily disassembled, and their components were recovered.