Recent Advances in 3D Printing Technologies for Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) batteries have heretofore raised burgeoning interest due to their cost effectiveness and high theoretical energy densities. However, the inherent porous and fluffy structure of sulfur impedes the path to constructing high-loading electrodes (over 5 mg cm^-2) for their practicability. Furthermore, especially in thick electrodes, challenges like the retarded redox kinetics, notorious polysulfide shuttling, and wanton electrode expansion seriously give rise to low sulfur utilization, poor rate performance, and unsatisfactory cycling stability. Constructing free-standing architectures has been demonstrated as an effective strategy to tackle the aforementioned issues for high-loading Li-S batteries. As an emerging technique, 3D printing (3DP) shows merits in rapidly fabricating precise microstructures with controllable loadings and rationally organized porosity. For the Li-S realm, 3DP offers optimized Li⁺/e^- transmission path with well-dispersed electrocatalysts, which achieves efficient polysulfide regulation and guarantees favorable performance. This review covers the design principle and preparation of printable inks, and their practical applications to manufacture self-supported frameworks (such as cathodes, anodes, and separators) for Li-S batteries. Challenges and perspectives on the potential future development of 3DP Li-S batteries are also outlined.