It was shown that Diglyme can be used to prepare a novel diglyme-based gel polymer (DOBn-GPE) suitable for sodium-based energy storage devices. This DOBn-GPE containing methacrylate-based polymers exhibits excellent high ionic conductivity (2.3 mS cm-1 at 20 °C), broad electrochemical stability (>5.0 V), and high mechanical stability.DOBn-GPE can be successfully used to fabricate sodium-ion capacitors, sodium-metal batteries, and sodium-ion batteries, with comparable performance to that of systems containing liquid electrolytes, at both room temperature and 60 °C. electrolytes at room temperature and 60 °C. The performance is comparable to systems containing liquid electrolytes.

Diglyme molecular solvated sodium ion complexes enable the superfast co-intercalation/de-intercalation into graphite interlayers, providing unprecedented prospects for the application of low-dimensional graphitic carbon as fast-charge sodium ion battery anode materials.

Furthermore, a thorough understanding of this novel co-doping process and its resulting solid electrolyte phase (SEI) by Raman spectroscopy and ultrasonic force microscopy is essential for improving the electrochemical performance of co-doping-based high-capacity energy storage systems. The results show that within the low voltage region (<0.3 V vs Na+/Na), a mechanically soft SEI layer is formed on the carbon anode surface compared to the electrode current collector surface, which does not affect the reversible co-doping of Na-diglyme with FLG. Meanwhile, the SEI layer formed on the nickel collector mainly contains hard and thin inorganic materials, which are electrochemically stable in the low-voltage region. This result clarifies the formation behaviour of SEI on the FLG anode surface in diglyme electrolytes , and providing experimental evidence for a fundamental understanding of Na-diglyme co-doping.