The practical application of lithium–sulfur batteries is hampered by the sluggish redox reaction kinetics and severe lithium polysulfide (LiPS) migration, especially under high sulfur loading and lean electrolyte scenarios. Strategies to catalyze the sulfur liquid/solid conversion within a “hermetic” nano-container have been proposed, where the LiPS migration and sluggish reaction kinetics can be simultaneously addressed. Herein, to realize rapid LiPS conversion and slow LiPS migration, the sulfur species are packed by a hermetic catalytic interface, constructed by the phosphorene/graphene heterostructure. The 2D phosphorene/graphene stacking has two unique benefits: 1) a direct electron transfer avoiding any insulating media, resulting in an exceptional catalytic effect on LiPS conversion; ii) favorable charge rearrangement that enhances chemisorption toward LiPS and limits LiPS crossover. The proposed highly flexible hermetic interface with strong van der Waals serves as a bifunctional nano-container to pack sulfur species and promote sulfur redox reactions, which gives rise to excellent battery performances: a high areal capacity of 5.57 mAh cm−2 under a low electrolyte/sulfur ratio of 5.7 mL g−1. This work affords a coupling strategy that embraces interfacial and structural engineering to promote kinetic reactions of sulfur conversions under electrolyte-lean conditions.