Novel NiCl₂ Nanosheets Synthesized via Chemical Vapor Deposition with High Specific Energy for Thermal Battery

Two-dimensional (2D) nanomaterials possessing a unique sheet structure, compared to correlative bulk materials, exhibit excellent properties, especially in the energy storage and energy conversion field. In this case, NiCl2 nanosheets with thicknesses of 2–8 nm are first prepared by a simple chemical vapor deposition method. For the Li–B/LiF–LiCl–LiBr/NiCl2 thermal battery, the specific energy of NiCl2 nanosheets increases from 510 W h kg–1 (NiCl2 rods) to 616 W h kg–1 at an operation temperature of 500 °C and a current density of 0.2 A cm–2. The 2D morphology and large numbers of defects not only improve the redox reaction rates and the lithium storage capacity, but also enhance the adsorption capacity with the flake-like binder MgO, which prolong the discharge time by suppressing the discharge product diffusion to the electrolyte. These results indicate that NiCl2 nanosheets have a great possibility to become a desirable candidate of cathode materials for assisting in the development of high energy output and provide a new way to restrain the immersion between the electrode and electrolyte.