With high melting point sodium tetrachloroaluminate ( NaAlCl4 ) as catholyte ( 157 ℃) , traditional sodium metal chloride batteries ( ZEBRA ) were usually operated at the temperature range of 270 to 350℃.In the paper,0. 2 mol/L sodium trifluomethanesulfonate (NaCF3SO3) was dissolved in an ionic liquid of 1-ethyl-3-methylimidazolium bistrifluoromethylsulfonyl imide ( EMIMTFSI ) and examined the resolution as the catholyte in order to lower down the working temperature of ZEBRA batteries to 175℃. The thermal stability and electrochemical window of the home made catholyte were tested using thermogravimetry and cyclic voltgrammetry.A planar cell,with Cu as the positive electrode,was built to evaluate the electrochemical performance of this Na/CuCl2 battery. Results showed that the EMIMTFSI based catholyte was a promising candidate to be applied for intermediate temperature ( 175 ℃) ZEBRA batteries. The planar intermediate Na/CuCl2 battery can be operated at 175℃ stably with this ionic liquid catholyte.