Meringue-derived hierarchically porous carbon as an efficient polysulfide regulator for lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries have garnered considerable attention as next-generation electrochemical energy storage systems because of their high theoretical energy density, natural abundance, and environmentally benign sulfur active material. However, the commercialization of Li-S batteries is still hampered by pronounced capacity fading over long-term cycling owing to lithium polysulfide shuttling behavior and parasitic reactions on the surface of the Li metal anode. Herein, nitrogen-doped porous carbon with a high specific surface area was derived from the sucrose-driven pore generation of bio-sustainable and low-cost meringue to overcome the abovementioned limitations and expedite the redox kinetics of sulfur species. After pyrolysis, carbon materials with a hierarchical pore structure were developed and utilized to coat the surface of the separators, denoted as the meringue-derived hierarchical porous carbon (MHPC) interlayer as polysulfide regulator. The experimental results demonstrate that the meringue-derived porous carbon interlayer effectively suppresses lithium polysulfide shuttling through physical and chemical trapping and facilitates redox reactions, leading to improved electrochemical performance. This work highlights a promising approach for converting sustainable biomass into energy storage materials.