Abstract:

As a high potential compound, NiCl₂ is an ideal anode material for high powder thermal battery, but its small specific surface area and poor conductivity hinder the application in thermal battery. In present study, The Ni-NiCl₂ composite with high specific surface area and conductivity was prepared by sublimation and in-situ synthesis, as cathode materials for thermal batteries. The precursor material NiCl₂·6H₂O was dried to dehydrate and sublimated at 850~900℃ in Ar atmosphere successively. And then the yellow sublimed powder was reduced at 300~500℃ in Ar + H₂ atmosphere for 1 h. Finally, the Ni and NiCl₂ composite powders were formed. Thermoanalysis, crystal structure, in-situ synthesis process and electrochemical performance of the powders were analyzed. The results show that NiCl₂ crystal grows along the direction perpendicular to c axis and formed a layered structure of 200-300 µm in the sublimation process. The resistivity of Ni-NiCl₂ composite is reduced with the increase of elemental Ni content. The discharge curve of LiSi︱LiCl-LiBr-LiF︱NiCl₂ thermal batteries with Ni-NiCl₂ (5wt% elemental Ni) as anode material at 1000 mA/cm² is more stable and has a shorter activation time, as compared to the discharge curve with pure NiCl₂ as anode material.

Key words: thermal batteries, cathode material, Ni-NiCl2 Composite: in-situ synthesis, discharge performance