A Review of the Application of Metal-Based Heterostructures in Lithium–Sulfur Batteries

Lithium–sulfur (Li-S) batteries are recognized as a promising alternative in the energy storage domain due to their high theoretical energy density, environmental friendliness, and cost-effectiveness. However, challenges such as polysulfide dissolution, the low conductivity of sulfur, and limited cycling stability hinder their widespread application. To address these issues, the incorporation of heterostructured metallic substrates into Li-S batteries has emerged as a pivotal strategy, enhancing electrochemical performance by facilitating better adsorption and catalysis. This review delineates the modifications made to the cathode and separator of Li-S batteries through metallic heterostructures. We categorize the heterostructures into three classifications: single metals and metal compounds, MXene materials paired with metal compounds, and heterostructures formed entirely of metal compounds. Each category is systematically examined for its contributions to the electrochemical behavior and efficiency of Li-S batteries. The performance of these heterostructures is evaluated in both the cathode and separator contexts, revealing significant improvements in lithium-ion conductivity and polysulfide retention. Our findings suggest that the strategic design of metallic heterostructures can not only mitigate the inherent limitations of Li-S batteries but also pave the way for the development of high-performance energy storage systems.