Lithium sulfur (Li-S) battery is a secondary battery with metallic lithium (Li) as the negative electrode and sulfur (S) as the positive electrode. Compared with traditional lithium-ion batteries, Li-S batteries have higher theoretical energy density and are therefore considered as one of the candidate technologies for the next generation of high-energy energy storage systems. Although Li-S batteries have the potential for high energy density, they still face some challenges, such as the "shuttle effect" of polysulfides: during charge and discharge, sulfur is converted into soluble polysulfides, which migrate to the negative electrode in the electrolyte and react with lithium, thereby affecting the cycling life. Sulfur has two main isotopes in nature, namely sulfur-32 and sulfur-34. These two isotopes are very similar in chemical properties, but due to their different masses, their behavior in certain physical and chemical processes may differ, a phenomenon known as the "isotope effect".