Work

Non-flammable polymeric ionic liquid hybrid electrolytes for high-stability solid-state sodium metal batteries

Year: 2025

Type: article

Abstract: Solid-state sodium metal batteries (SMBs) show promise for next-generation energy storage, but challenges remain in developing electrolytes that balance safety, performance, and longevity. This study introduces a hybrid electrolyte system for SMBs, combining a poly(diallyldimethylammonium) bis(fluorosulfonyl)imide polymer matrix with a sodium bis(fluorosulfonyl)imide in N-butyl- N -methylpyrrolidinium bis(trifluoromethyl sulfonyl)imide ionic liquid electrolyte. The optimized hybrid electrolyte exhibits a sodium ion conductivity of 2.1 mS cm −1 at 70 °C and an oxidative stability of 4.8 V vs Na + /Na. Electrochemical characterization reveals efficient sodium plating/stripping with a critical current density of 8.5 mA cm −2 . X-ray photoelectron spectroscopy identifies a NaF-rich interphase at the sodium metal surface, contributing to interfacial stability. An all-solid-state SMB utilizing this electrolyte and a sodium vanadium phosphate cathode demonstrates stable cycling at 60 °C, retaining 75 % capacity after 2000 cycles. These results highlight the potential of hybrid electrolytes in advancing safe, high-performance solid-state SMBs for future energy storage applications.

Source: Chemical Engineering Journal

DOI: 10.1016/j.cej.2025.167657

Authors: Eldho Edison, Daniel F. Abbott, Shivaprakash N. Ramakrishna, Victor Mougel, Markus Niederberger

Institution: ETH Zurich

Language: English

Topic: Advanced Battery Materials and Technologies

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: hybrid

Estimated APC paid: $4,830