With limited amounts of fossil fuels and increasing demand for efficient energy management, lithium-ion batteries (LIBs) have been a leading power source for hybrid electric vehicles and large-scale energy storage systems. However, rising price of lithium sources has become a significant concern, caused by increasing market demand for lithium and limited amounts of lithium resources. In this respect, sodium-based batteries have been considered an alternative to the LIBs due to the abundance of sodium resources in nature.¹ Like LIBs, enhancing the battery safety is a significant concern, because use of highly flammable organic solvents may trigger safety problems. Gel polymer electrolytes present many potential advantages, including enhanced safety, good interfacial contact, easy processing to make thin film and flexibility in the battery design, as compared to conventional separators.² In this study, we prepared polyurethane (PU)-based gel polymer electrolyte (GPE) composed of PU polymer matrix and sodium-ion liquid electrolyte, which exhibited good compatibility with liquid electrolyte and superior electrochemical properties. The PU GPE was employed to assemble the Na/Na₃V₂(PO₄)₃ cells. Electrochemical performance of the sodium cells was enhanced by employing the PU GPE.

References

1. M.D. Slater, D. Kim, E. Lee and C.S. Johnson, Adv. Funct. Mater., 23, 947-958 (2013).
2. H. Gao, B. Guo, J. Song, K. Park and J.B. Goodenough, Adv. Energy Mater., 5, 1402235 (2015).