<p>The “shuttle effect” and the sluggish redox kinetics induced by polysulfides have significantly hindered the commercialization and practical application of lithium-sulfur batteries. In this study, a novel β-ketoenamine covalent organic framework (TT COF) is synthesized via a Schiff base reaction at room temperature and then chelates with cobalt ions through N/O diatomic lone pair electrons in β-ketoenamine and carbonyl groups. The cobalt nanoparticles are subsequently anchored onto the surface of TT COF-derived carbon under high-temperature pyrolysis. This TT COF-derived hosting material features a unique three-dimensional reticulate structure, which significantly enhances the surface area. Furthermore, the anchoring of cobalt nanoparticles improves the redox kinetics of polysulfides. As expected, the prepared sulfur cathode composite exhibits outstanding electrochemical performance, including a high initial discharge capacity (1556 mAh g⁻¹ at 0.1 C), excellent rate performance (760 mAh g⁻¹ at 3 C), and outstanding cycling life (490.6 mAh g⁻¹ after 2000 cycles at 2 C). This research presents a simple and effective strategy to improve the redox kinetics of LiPSs as well as suppress the shuttle effect, thereby enhancing the electrochemical performance of lithium sulfur batteries and facilitating their commercialization.</p>