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Rational design of sulfur host materials with high electrical conductivity and strong polysulfides (PS) confinement is indispensable for high-performance lithium-sulfur (Li-S) batteries. This study presents one type of new polymer material based on main-chain imidazolium-based ionic polymer (ImIP) and carbon nanotubes (CNTs); the polymer composites can serve as a precursor of CNT/NPC-300, in which close coverage and seamless junction of CNTs by N-doped porous carbon (NPC) form a 3D conductive network. CNT/NPC-300 inherits and strengthens the advantages of both high electrical conductivity from CNTs and strong PS entrapping ability from NPC. Benefiting from the improved attributes, the CNT/NPC-300-57S electrode shows much higher reversible capacity, rate capability, and cycling stability than NPC-57S and CNTs-56S. The initial discharge capacity of 1065 mA h g−1 is achieved at 0.5 C with the capacity retention of 817 mA h g−1 over 300 cycles. Importantly, when counter bromide anion in the composite of CNTs and ImIP is metathesized to bis(trifluoromethane sulfonimide), heteroatom sulfur is cooperatively incorporated into the carbon hosts, and the surface area is increased with the promotion of micropore formation, thus further improving electrochemical performance. This provides a new method for optimizing porous properties and dopant components of the cathode materials in Li-S batteries. [ABSTRACT FROM AUTHOR]

Hollow nanostructures are one of promising sulfur host materials for lithium–sulfur (Li–S) batteries, but the ineffective contact among discrete particles usually generates overall poor electrical conductivity and low volumetric energy density. A new interfused hollow nitrogen‐doped carbon (HNPC) material, derived from imidazolium‐based ionic polymer (ImIP)‐encapsulated zeolitic imidazolate framework‐8 (ZIF‐8), is reported. A novel method for ZIF‐8 disassembly induced by the decomposition of the ImIP shell is proposed. The unique structural superiority gives the resultant electrodes remarkable cycling stability, high rate capability, and large volumetric energy density. A stable reversible discharge capacity over 562 mA h g−1 at 2 C is achieved after prolonged cycling for 800 cycles and the average capacity decay per cycle is as low as 0.035%. The electrochemical performance achieved greatly surpasses that of ZIF‐8‐derived carbon matrices and conventional nitrogen‐doped carbon materials. This proposed methodology opens a new avenue for the design of hollow‐structured carbon nanoarchitectures with target functionalities. [ABSTRACT FROM AUTHOR]

A heteroatom‐doped carbon material for high‐performance lithium–sulfur batteries is reported in article number 1703936 by Xiaoju Li, Ruihu Wang, and co‐workers. The integration of main‐chain imidazolium‐based ionic polymer and carbon nanotubes (CNTs) yields porous materials. They can serve as an effective sulfur host, and both the electrical conductivity from CNTs and polysulfide entrapping ability from the heteroatom‐doped carbons are inherited and strengthened. [ABSTRACT FROM AUTHOR]