Synthesis and discharge performances of NiCl2 by surface modification of carbon coating as cathode material of thermal battery

摘要

The high solubility in molten salt and low conductivity of NiCl2, compared with traditional FeS2 and CoS2, have become the restrictions for its extensive application in cathode materials of thermal batteries. In this study, carbon coated NiCl2 cathode is successfully fabricated by the carbonization of stearic acid. The high specific energy of 641 Wh kg(-1) at current densities of 0.5 A cm(-2) are observed for the carbon coated NiCl2 thermal batteries, which is higher than the pure NiCl2 with 475 Wh kg(-1). The high specific energies and high-current discharge ability are attribute to the graphite and amorphous carbon layers on the surface of NiCl2 crystalline, which were detected by TEM after carbonization. The graphite layers can improve the conductivity of NiCl2. Meanwhile the coated carbon structure could reduce the solubility of NiCl2 in molten salt. (C) 2017 Elsevier B.V. All rights reserved.