Diamondoid All‐Carbon Porous Aromatic Framework Host for Lithium–Sulfur Batteries

Abstract Lithium‐sulfur batteries (LSBs) hold incredible potential as next‐generation energy storage systems. However, practical applications of LSBs are significantly hindered by several critical challenges. For the first time, scalable all‐carbon porous 3D polymers (3DPs) that do not contain heteroatoms or functional groups and do not require post‐functionalization are investigated as hosts in lithium–sulfur batteries, demonstrating enhanced cycling stability and overall battery performance. The pyrene‐containing 3DP exhibits 75% capacity retention after 600 cycles at 1 C and 52% capacity retention after 1300 cycles at 0.2 C, better than phenyl comprising 3DP. Furthermore, even at higher sulfur loading (4.1 mg cm⁻²) with an electrolyte/sulfur ratio of 5 µL mg⁻¹, pyrene 3DP displayed a high capacity of 600 mA h g⁻¹ and stable performance over 250 cycles with negligible capacity fade. The defined pore structure of 3DPs prevents the migration of polysulfides through physical confinement and the large π‐clouds of 3DPs interact with the negative charge‐bearing polysulfides generated in charge–discharge cycles through anion‐π interaction. In this way, The design ensures that the host 3DPs interact with neutral sulfur and anionic polysulfides, resulting in an excellent performance.