Synergistic catalysis of quasi-metal-organic framework-derived CoO and Ti3C2 MXene for high-performance lithium‑sulfur batteries

The shuttle effect of lithium polysulfides (LiPSs) and sluggish sulfur redox kinetics represent critical bottlenecks that hinder the practical application of lithium‑sulfur (Li S) batteries. Herein, we report a synergistic catalytic system based on a quasi-MOF-derived CoO/Ti 3 C 2 MXene heterostructure (q-ZIF/CoO@Ti 3 C 2 ) as an advanced sulfur host. This architecture is constructed by in-situ growth of ZIF-67 on Ti 3 C 2 nanosheets, followed by a controlled low-temperature calcination. This mild thermal treatment partially removes organic ligands, yielding well-dispersed, oxygen-vacancy-rich CoO nanoparticles while preserving the porous framework of the parent MOF. The resulting material integrates multiple functionalities: the porous quasi-MOF structure accommodates sulfur volume expansion, the oxygen-vacancy-rich CoO nanoparticles provide abundant active sites for accelerating the catalytic conversion of LiPSs, and the conductive Ti 3 C 2 substrate ensures rapid electron transport and offers strong chemical anchoring for LiPSs. Consequently, the sulfur-loaded q-ZIF/CoO@Ti 3 C 2 cathode delivers exceptional electrochemical performance with a high initial capacity of 1004 mAh g −1 at 2C and remarkable stability (586 mAh g −1 after 1000 cycles). This work provides a new paradigm for developing high-performance sulfur hosts through synergistic adsorption-catalysis strategies.