The NiCl2/NiS2@C double active composite cathodes with surface synergistic effects for high-power thermal battery

Although nanocrystallization and carbon modification could improve the specific capacity of cathode materials, the deficiency of high voltage makes it difficult to satisfy the need of high-power thermal battery. Hence, the carbon coated NiCl2/NiS2 double active cathode materials are fabricated by the simple ball milling-sintering method. The NiCl2/NiS2@C cathodes have the excellent discharge performances (initial voltage with 2.78 V, specific capacity with 946.08 mAh g(-1) and energy with 1497.11 Wh kg(-1) in 0.1 A cm(-2) at 500 degrees C under cut-off voltage of 0.5 V) when the quality ratio between NiCl2 and NiS2 is about 1:1. A prominently enhanced specific energy could be attributed to surface synergistic effects which from high voltage of NiCl2, high capacity of NiS2 and high conductivity of carbon. Especially, improving voltage and capacity of ball milling are superior to sintering and carbon coating through contrast experiments. Furthermore, the morphology of post-electrodes indicates that carbon coating could solve the structure collapse question of NiCl2/NiS2 cathodes in high temperature and current density. These findings open a new avenue for developing double active composites as high-power cathodes for thermal battery. (C) 2019 Published by Elsevier B.V.