3D, Mutually Embedded MOF@Carbon Nanotube Hybrid Networks for High-Performance Lithium-Sulfur Batteries

Metal-organic frameworks (MOFs) hybridized with a conductive matrix could potentially serve as a sulfur host for lithium-sulfur (Li-S) battery electrodes; so far most of the previously studied hybrid structures are in the powder form or thin compact films. This study reports 3D porous MOF@carbon nanotube (CNT) networks by grafting MOFs with tailored particle size uniformly throughout a CNT sponge skeleton. Growing larger-size MOF particles to entrap the conductive CNT network yields a mutually embedded structure with high stability, and after sulfur encapsulation, it shows an initial discharge capacity of ≈1380 mA h g −1 (at 0.1 C) and excellent cycling stability with a very low fading rate. Furthermore, owing to the 3D porous network that is suitable for enhanced sulfur loading, a remarkable areal capacity of ≈11 mA h cm −2 (at 0.1 C) is obtained, which is much higher than other MOF-based hybrid electrodes. The mutually embedded MOF@CNTs with simultaneously high specific capacity, areal capacity, and cycling stability represent an advanced candidate for developing high-performance Li-S batteries and other energy storage systems.