Eutectic salt for thermal battery

The invention relates to eutectic salt for a thermal battery, and belongs to the technical field of electrochemistry. The eutectic molten salt for the thermal battery is prepared from LiCl, LiBr, LiF and BaCl2, wherein the mass percent content of the LiCl is 11 percent to 20 percent, the mass percent content of the LiBr is 50 percent to 70 percent, the mass percent content of the LiF is 6 percent to 12 percent, and the mass percent content of the BaCl2 is 16 percent to 30 percent. According to the invention, LiCl-LiBr-LiF-BaCl2 eutectic molten salt is adopted, and the melting point is 421.6 DEG C; the melting point of the eutectic salt is about 18.2 DEG C lower than that of common eutectic salt of LiCl-LiBr-LiF (the melting point is 439.8 DEG C). The eutectic salt has the following remarkable effects: firstly, the eutectic salt is prepared into an electrolyte to be used in the thermal battery, so that the working temperature area of the thermal battery can be prolonged, and the thermal life and the working li