This study presents a novel approach to enhance the redox kinetics in lithium-sulfur (Li–S) batteries by utilizing quantum spin exchange interactions in Mg phthalocyanine (MgPc) anchored on fluorinated carbon nanotubes (FCNT). The MgPc@FCNT composite exhibits single active Mg sites with axial displacement, which enables efficient spin polarization, enhancing the adsorption of lithium polysulfides (LiPSs) and facilitating electron tunneling in Li–S batteries. Density functional theory (DFT) calculations confirm that the electronic spin polarization in MgPc@FCNT increases the adsorption energy toward LiPSs intermediates and promotes the tunneling process of electrons, leading to improved electrochemical performance. The MgPc@FCNT demonstrates an initial capacity of 6.1 mAh cm⁻² even under high sulfur loading of 4.5 mg cm⁻² and maintains 5.1 mAh cm⁻² after 100 cycles, indicating excellent cycle stability and low capacity decay. The study highlights the potential of main group single-atom catalysts in enhancing the performance of Li–S batteries through spin engineering. The MgPc@FCNT composite shows superior catalytic activity and reaction kinetics compared to other catalysts, with a significantly lower activation energy barrier for sulfur evolution reactions. The results demonstrate that the rational design of spin-polarized electron exchange in MgPc@FCNT can optimize the catalytic activity and improve the overall performance of Li–S batteries. The study provides a new perspective for the development of high-performance Li–S batteries using main group single-atom catalysts.This study presents a novel approach to enhance the redox kinetics in lithium-sulfur (Li–S) batteries by utilizing quantum spin exchange interactions in Mg phthalocyanine (MgPc) anchored on fluorinated carbon nanotubes (FCNT). The MgPc@FCNT composite exhibits single active Mg sites with axial displacement, which enables efficient spin polarization, enhancing the adsorption of lithium polysulfides (LiPSs) and facilitating electron tunneling in Li–S batteries. Density functional theory (DFT) calculations confirm that the electronic spin polarization in MgPc@FCNT increases the adsorption energy toward LiPSs intermediates and promotes the tunneling process of electrons, leading to improved electrochemical performance. The MgPc@FCNT demonstrates an initial capacity of 6.1 mAh cm⁻² even under high sulfur loading of 4.5 mg cm⁻² and maintains 5.1 mAh cm⁻² after 100 cycles, indicating excellent cycle stability and low capacity decay. The study highlights the potential of main group single-atom catalysts in enhancing the performance of Li–S batteries through spin engineering. The MgPc@FCNT composite shows superior catalytic activity and reaction kinetics compared to other catalysts, with a significantly lower activation energy barrier for sulfur evolution reactions. The results demonstrate that the rational design of spin-polarized electron exchange in MgPc@FCNT can optimize the catalytic activity and improve the overall performance of Li–S batteries. The study provides a new perspective for the development of high-performance Li–S batteries using main group single-atom catalysts.