With the synergies of multiple elements, bimetallic sulfides exhibit excellent performance as splendid electrode materials and effective catalysts. However, large-scale synthesis of high-performance single-phase multicomponent sulfides has always been a challenge. Based on thermodynamic calculations, the intermediate phases NiS2 and Co3S4 are devoted to the synthesis of single-phase Ni0.5Co0.5S2. Because the reaction from NiS2 and Co3S4 to Ni0.5Co0.5S2 goes through a lower energy, it thermodynamically contributes to achieving a single-phase structure. Thus, single-phase Ni0.5Co0.5S2 can be simply and quickly prepared by two-step sintering and successfully scalable for mass production. This technique can extend to the whole ingredients Ni1-xCoxS2. Ni0.5Co0.5S2 demonstrates excellent thermal stability and good conductivity. It delivers a specific capacity of 671 mAh·g-1 and a specific energy of 1173 Wh·kg-1 when applied to a thermal battery cathode, which are increased by 18.6% and 25.0%, respectively, compared to pristine NiS2 (566 mAh·g-1) and CoS2 (537 mAh·g-1). This work proposes an innovative sintering method, which is applicable for cost-efficient and large-scale synthesis of single-phase multicomponent sulfides.
Keywords: Ni0.5Co0.5S2; high energy; large-scale; sintering technique; thermal battery cathode.