# A Review of Lithium-Sulfur Batteries Based on Metal-Organic Frameworks: Progress and Prospects
## 2 Metal-Organic Frameworks for Cathode Applications in Lithium-Sulfur Batteries
### Metal-Organic Framework Composites
#### 2.2.3 Composites with Conductive Polymers  
The integration of conducting polymers with MOFs represents an alternative efficient strategy for constructing intricate structures aimed at enhancing the performance characteristics of MOF-based cathode materials. On one hand, conducting polymers substantially bolster the inherently low conductivity of sulfur-based cathodes and expedite electron transport, thereby further elevating the electrochemical performance. On the other hand, these polymers harbor polar bonds, including C-H and N-H, which facilitate chemical anchoring of polysulfides (PSs) and effectively mitigate the shuttling effect [55]. Notably, among the variety of conductive polymers, polypyrrole (PPY) and polyaniline (PANI) [56; 57] exhibit exceptional electrical conductivity. The incorporation of MOFs into cathode materials significantly amplifies the electrochemical performance of LSBs [58].  
[PERSON] et al. [59] added polyaniline to the precursor of ZIF-67 by an in situ growth technique in the preparation of capacitors, which allowed the nucleation process of ZIF-67 to take place in situ under a PANI coating (Figure 8a). Since the fixed central Co(II) ions are electrically neutral and consequently unable to support the free flow of charged electrons, the incorporation of PANI (polyaniline), which boasts exceptional conductivity, ductility, and capacitance, becomes pivotal. The in situ growth of PANI within the ZIF-67 framework enables electrons to traverse the composite structure efficiently. This integration  
Figure 7: **(a)** Schematic of the synthesis of MOF-74-Ni/CNT (reprinted/adapted with permission from [52]; copyright 2018, _Journal of Electroanalytical Chemistry_). **(b)** Diagram of the formation process of CNT-NC@GC/S cathode material. **(c)** TEM image of precursor ZIF-86 ZIF-67 and corresponding elemental mapping (reprinted/adapted with permission from [53]; copyright 2020, _Electrochimica Acta_). **(d)** Schematic of the synthesis of CoMoS\({}_{3.13}\)@NCNTs composite. **(e)** Cycling diagram of CoMoS\({}_{3.13}\)@NCNTs at 0.2 C Cycle diagram of CoMoS\({}_{3.13}\)@NCNTs with CoMoS\({}_{3.13}\) (reprinted/adapted with permission from [55]; copyright 2024, _ACS Sustainable Chemistry & Engineering_).  
not only substantially boosts the specific capacity but also enhances cycling stability, thereby contributing significantly to the advancement of anode materials for LSBs. As depicted in Figure 8b, the composite cathode demonstrates an initial discharge-specific capacity of 1220.1 mAh g\({}^{-1}\) at a current density of 0.1 C, and maintains a reversible capacity of 1018.7 mAh g\({}^{-1}\) after 100 cycles, with a capacity retention rate of 83.5%. [PERSON] et al. [60] also employed a composite of PANI with MOFs, utilizing hydrochloric acid etching on ZIF-67 followed by high-temperature activation to obtain nitrogen-doped carbon (NC). Subsequently, three-dimensional crosslinked PANI fibers/NC (3 CPC) were synthesized through in situ polymerization of aniline (Figure 8c). This 3D interwoven framework is characterized by a high density of micropores and mesopores, which effectively promote sulfur immobilization and enhance ion diffusion. Beyond the physical confinement of LiPSs by the NC framework, the nitrogen-containing functional groups and \(\pi\)-conjugated systems on the PANI framework can serve as active sites or groups to chemically immobilize polysulfides, thereby suppressing the shuttle effect.