Low-concentration electrolyte and application thereof in low-temperature sodium-ion battery

The invention discloses a low-concentration electrolyte and application thereof in a low-temperature sodium-ion battery, and belongs to the technical field of sodium-ion batteries. The low-concentration electrolyte is formed by mixing a sodium salt and an ether organic solvent, wherein the concentration of the sodium salt in the ether organic solvent is 0.05-0.9 mol/L. Due to the low concentration of the sodium salt, the cost of the electrolyte can be reduced, the electrolyte can have relatively low viscosity and relatively high ionic conductivity at a low temperature, and ion transmission in the electrolyte at the low temperature is ensured; a solid electrolyte interface film with high stability and high ion conduction can be constructed on the surface of the electrode through regulation and control of the sodium salt and the ether solvent, so that the low-temperature performance of the battery is further improved. The electrolyte disclosed by the invention is low in cost and simple in formula, and has a con