Electrode Design with Integration of High Tortuosity and Sulfur-Philicity for High-Performance Lithium-Sulfur Battery

Practical applications of Li-S batteries are hindered by the dissolution/diffusion loss of sulfur-related active materials in cathode and dendrite growth in Li metal anode. Here we present an integrated sulfur cathode design on tortuosity and sulfur-binding affinity parameters for mitigating diffusion loss of sulfur-based active materials. The high sulfur-philicity property (from oxygen functional groups, 16% in concentration) in reduced graphene oxide (rGO) host favors bonding with sulfur species to mitigate their diffusion/dissolution loss, while the high tortuosity (13.24, from horizontal arrangement of rGO sheets) can localize the soluble active materials within the host rather than outward diffusion loss with subsequent uneven redeposition. With this integrated concept, we achieved ultrahigh cathode areal capacities of 21 mAh cm−2 with 98.1% retention after 160 cycles, surpassing those electrodes with lower tortuosity and sulfur-philicity. In addition, same rGO host suppresses dendrite growth in Li anode, enabling 278% prolonged cycle life in the full cell.