CNT-assembled dodecahedra core@nickel hydroxide nanosheet shell enabled sulfur cathode for high-performance lithium-sulfur batteries

Herein, we report the construction of three-dimensional hollow core@shell structure composed of N-doped CNT-assembled dodecahedra core derived from ZIF-67 and Ni(OH)(2) nanosheet shell as the sulfur scaffold for Li-S batteries. The obtained sulfur cathode demonstrates outstanding electrochemical performance, including a high reversible capacity (1321 mAh g(-1) at 0.1 C), excellent rate capability (1030 and 753 mAh g(-1) at 1 and 3 C, respectively), and superior cycling stability (611 mAh g(-1) after 1000 cycles at 3 C). The enhancement in electrochemical performance can be ascribed to the unique core@shell architecture: the interconnected CNT-assembled dodecahedra core provides rapid Li+/e(-) transport and sufficient free space for volume change; the Ni (OH)(2) nanosheet shell not only acts as a durable physical barrier, but also serves as the polar material to restrain the dissolution of polysulfides with chemical interaction. In addition, in-situ nitrogen doping in CNTs introduces rich defects and active sites for polysulfides adsorption. This work provides a promising direction for high performance Li-S batteries by coating strong polar material on carbon materials.