The dual-play of carbon nanotube embedded with CoNi N codoped porous polyhedra toward superior Lithium–Sulfur batteries

Highlights: • The conductive network composed of carbon nanotubes facilitates electron transfer. • The composite material's high porosity and large specific surface area help to physically limit polysulfides, while effectively exposing the active centers of sulfur redox reactions. • The N-doped and bimetal particles and CoNi–N–C coordination in the composite Co_0.75Ni_0.25-NC/CNTs/S can be used as multiple adsorption and catalytic sites to chemically capture the polysulfide and accelerate its transformation reaction, which promotes the transformation of Li₂S₆–Li₂S₄ and the subsequent Li₂S₄–Li₂S₂ process. -- Abstract: Rational design of sulfur host materials is the key to the development of superior lithium-sulfur batteries. Here, we designed a composite conductive scaffold that is expected to establish a conductive, adsorption, and catalytic barrier layer to inhibit polysulfide shuttle and improve Lithium-sulfur battery performance. The large scaffold of the carbon nanotube framework enables long-range conductivity and effective exposure of active sites. The hollow polyhedron produced by the pyrolysis bimetallic organic framework MOFs precursor contributes to a variety of adsorption and catalytic sites, enhancing sulfur confinement and conversion, thus contributing to rapid and long-lasting sulfur electrochemistry. Due to these favorable features, Lithium-sulfur batteries achieve good electrochemical performance, exerts an initial discharge capacity of 1320.8 mA h g⁻¹ at 0.1 C.