Synthesis of Honeycomb-Like Co 3 S 4 /MoS 2 Composites with Hollow Structure As Anode Materials for High-Performance Lithium-Ion and Sodium-Ion Batteries

Hollow honeycomb-like Co3S4/MoS2 composites were fabricated through the zeolitic imidazolate framework-67 (ZIF-67) as a precursor and followed by two sulfuration processes. Co3S4 hollow nanocubes were first prepared using ZIF-67 and thioacetamide co-pyrolysis. Then, MoS2 nanosheets were grown on the surface of Co3S4 nanocubes and formed Co3S4/MoS2 hollow composites. The outside flake-like MoS2 interlaced together, thus formed a honeycomb-like structure. The combination of Co3S4 and MoS2 significantly improved the electrochemical performance compared with single Co3S4 or MoS2. The presence of honeycomb-like MoS2 not only stabilized the structure of inner Co3S4 nanocubes to the maximum extent during the discharge/charge process, but also supplied more Li+ and Na+ insertion/extraction sites, increased the contact area between electrode material and electrolyte, and restrained volume expansion of inner Co3S4 nanocubes. The capacity of the Co3S4/MoS2 was maintained at 365 mAh g−1 during 1000 cycles at 1 A g−1 when used as anode material in lithium-ion batteries. At even a higher current density of 2 A g−1, the capacity of the Co3S4/MoS2 stabilized at 248 mAh g−1 during 1000 cycles. When used as anode material in sodium-ion batteries, it still has a capacity of 230 mAh g−1 at 1 A g−1, which is superior to that of the single Co3S4 nanocubes. Co3S4/MoS2 composites exhibited enhanced capacity and excellent cycling performance due to its complementarity, hollow structure and synergetic effect between Co3S4 and MoS2.