Sodium-ion batteries (SIBs) have the advantages of abundant resources and low cost, making them potential candidates for the next-generation large-scale energy storage technology. However, the capacity fade during cycling used in sodium-ion batteries is a major challenge. The rational design of the electrolyte is one of the ways to solve these problems. In this work, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (HFE) is introduced into a sodium hexafluorophosphate (NaPF