A Multifunctional Secondary Based on Heterogeneous Co‐MnO@NC for Depth‐Induced Deposition and Conversion of Polysulfides in Li─S Batteries

Abstract

AbstractThe conductive carbon‐based interlayer, as the secondary current collector in the self‐dissolving battery system, can effectively capture escaping cathode active materials, inducing deep release of remaining capacity. In the multi‐step reactions of Li─S batteries, the environmental tolerance of the conductive carbon‐based interlayer to polysulfides determines the inhibition of shuttle effects. Here, a modified metal–organic framework (Mn‐ZIF67) is utilized to obtain nitrogen‐doped carbon‐coated heterogeneous Co‐MnO (Co‐MnO@NC) with dual catalytic center for the functional interlayer materials. The synergistic coupling mechanism of NC and Co‐MnO achieves rapid deposition and conversion of free polysulfide and fragmented active sulfur on the secondary current collector, reducing capacity loss in the cathode. The Li─S battery with Co‐MnO@NC/PP separator maintains an initial capacity of 1050 mAh g−1 (3C) and excellent cycle stability (0.056% capacity decay rate). Under extreme testing conditions (S load = 5.82 mg cm−2, E/S = 9.1 µL mg−1), a reversible capacity of 501.36 mAh g−1 is observed after 200 cycles at 0.2 C, showing good further practical reliability. This work demonstrates the advancement application of Co‐MnO@NC bimetallic heterojunctions catalysts in the secondary current collector for high‐performance Li─S batteries, thereby providing guidance for the development of interlayer in various dissolution systems.