Hydrothermal synthesis of binary disulfide Co x Cu 1-x S 2 as cathode material for high-performance lithium thermal battery

Abstract The hollow microsphere structure materials binary disulfide Co1-xCuxS2 (x = 0, 0.05, 0.10, 0.15, 0.20, 0.25) were synthesized by hydrothermal method with cobalt sulfate, copper sulfate, and sodium thiosulfate. The structure, morphology, and composition of Co1-xCuxS2 were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), and energy dispersive spectrometer (EDS). The influence of cobalt and copper content in Co1-xCuxS2 cathode material on the discharge performance of the cell was investigated. The experimental results show that the Co0.95Cu0.05S2 sample possesses the largest number of hollow microspheres, the internal resistance of the cell was lower and the specific capacity of the cell is higher. The results of constant current discharge showed that the optimal composition Co0.95Cu0.05S2 exhibits an ultra-high specific capacity of 531.8 mAh g-1 at 450℃ and the current density of 100 mA·cm-2 with the cut-off voltage of 1.5V. The best discharge temperature of Co0.95Cu0.05S2 was 450℃.