Facile and low-temperature strategy to prepare hollow ZIF-8/CNT polyhedrons as high-performance lithium-sulfur cathodes

Great efforts have been devoted to developing novel cathodes to alleviate the shuttle effect of lithium polysulfides (LiPSs). The limited intrinsic conductivity of metal–organic frameworks (MOFs) compels their utilization as the templates to prepare carbonaceous Li-S battery cathodes after high-temperature treatments. The facile and low-temperature fabrication methods of MOF-derived cathodes are largely unexplored. Herein, the hybrid of hollow zeolitic imidazolate framework-8 (ZIF-8) polyhedron functionalized with carbon nanotube (HZIF/CNT) cathode is fabricated via facile tannic acid (TA) etching and low-temperature treatment. The conductive HZIF/CNT structure with ordered hollow ZIF-8 morphology, rich heteroatoms functionalities, and hydrophilic surface endow strong adsorption of LiPSs, boosted LiPSs conversion kinetics, and regulated Li₂S deposition. As a result, S@HZIF/CNT cathode delivers a superior initial capacity of 1371 mAh g⁻¹ at 0.1C and excellent rate retention at 3.0C (696 mAh g⁻¹). The remarkable cycling stability is evaluated for 500cycles at 0.5C with a 0.073% capacity decay per cycle. Moreover, the cathode with a high sulfur loading of 3.41 mg cm⁻² delivers an initial capacity of 696.4 mAh g⁻¹ at 1.0C and stable cycling performance over 200cycles. This work opens a facile and low-energy route to design advanced sulfur cathodes for high-performance Li-S batteries.