Synthesis and electrochemical analysis of S/ZIF-67@rGO composite cathodes for lithium-sulfur batteries

In this work, we developed ZIF-67@rGO composite by coating reduced graphene oxide (rGO) on the surface of ZIF-67 via the spray drying method to obtain a highly efficient sulfur host for lithium-sulfur (Li–S) batteries. The resulted ZIF-67@rGO composite possesses a hierarchical architecture, in which ZIF-67 polyhedron closely clustered and coated by rGO. The rGO coating shell could maintain the structural stability and provide high conductivity paths for effective charge transport. The ZIF-67 core possesses abundant adsorptive site to provide chemical interaction with lithium polysulfides (LiPSs). The size range of ZIF-67@rGO particles is about 2–5 μm, and the diameters of ZIF-67 nanoparticles are distributed between 500 and 900 nm. As results, the S/ZIF-67@rGO composite achieved the high initial discharge capacity of 1130.1 mAh g⁻¹ and a capacity of 942.6 mAh g⁻¹ remained after 100 cycles. This facile approach of spray-drying will open an alternative pathway to prepare an efficient and promising electrode material for advanced Li–S batteries.