Design and synthesis of core–shell porous carbon derived from porous polymer as sulfur immobilizers for high-performance lithium–sulfur batteries

Lithium–sulfur (Li–S) batteries have been receiving utmost interest in virtue of their high theoretical capacity, but the undesirable cycling performance caused by soluble polysulfide shuttling between anode and cathode has hindered its practical applications. This study represents the first report on microporous carbon “shell” derived from carbonization of porous polymer to encapsulate ordered mesoporous carbon “core” functioning as sulfur immobilizers for Li–S batteries. The dual-pore carbon matrix combines the excellent confinement ability of micropores (0.5 nm) and large pore volume (1.432 cm3 g−1) to improve sulfur loading capacity (71.3 wt%), thereby maintaining a capacity of 535 mAh g−1 after 100 cycles and a low fading rate of 0.30% per cycle. The merits of our exclusive core–shell architecture are established through comparative electrochemical performance analyses of individual mesoporous carbon and microporous carbon composites. Our experimental results bring out the excellent electrochemical performance of porous carbon composites, benefitting from its outstanding sulfur loading mass improving its overall capacity and its confinement capacity in the micropores alleviating polysulfide dissolution. Graphical abstract