Single-phase NiS2, which was hardly prepared by conventional processes such as mechanical milling or precipitation reaction, was prepared using the spark plasma sintering (SPS) process. Using porous Ni (porosity 95%) as a starting material, similar-shaped porous NiS2 (porosity 89%), containing trace amounts (ca. 3%) of NiS, and finally single-phase NiS 2 powder were obtained by the SPS process. The electrochemical tests demonstrated that the present NiS2 samples showed the initial discharge capacity of ca. 820 mAh g-1, which was ∼94% of the theoretical value. The capacity retention after 10 cycles was ca. 19%, and such rapid degradation was mainly attributable to the irreversibility of the Li extraction from the lithiated (discharged) NiS2 electrodes and the electrical disconnections among the active materials, carbon powders, and/or current collectors.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry