A high performance Li/S cell cathode with hierarchical architecture composed of ketjenblack@mesoporous carbon/sulfur hybrid

A ketjenblack@mesoporous carbon (KB@Meso-C) hybrid with hierarchical architecture was prepared by carbonizing the ketjenblack@metal-organic framework hybrid (KB@MOF-5). Meso-C with large pore volume can host a large amount of sulfur and alleviate the dissolution and migration of the lithium polysulfides, while the highly conductive KB uniformly distributed within the hybrid matrix can provide fast electron transportation pathways and high specific surface area. When 62 wt% of sulfur is encapsulated, KB@Meso-C/S cathode shows the initial discharge capacity of 997 mA h g⁻¹, and retains 665 mA h g⁻¹ after 300 cycles at 1 C, with 0.13% capacity decay per cycle and 97.70% Coulombic efficiency. In addition, KB@Meso-C/S cathode presents a remarkable rate capability, reaching 518 mA h g⁻¹ at 2 C. The hierarchical KB@Meso-C/S presents comparable performance to other complicated composites. The pore size distribution plays a major role to confine polysulfide and alleviate the shuttle effect for KB@Meso-C/S cathode.