Coordinating Interface Polymerization with Micelle Mediated Assembly Towards Two-Dimensional Mesoporous Carbon/CoNi for Advanced Lithium-Sulfur Battery

Lithium-sulfur battery has attracted significant attention by virtues of their high theoretical energy density, natural abundance, and environmental friendliness. However, the notorious shuttle effect of polysulfides intermediates severely hinders its practical application. Herein, a novel 2D mesoporous N-doped carbon nanosheet with confined bimetallic CoNi nanoparticles sandwiched graphene (mNC-CoNi@rGO) is successfully fabricated through a coordinating interface polymerization and micelle mediated co-assembly strategy. mNC-CoNi@rGO serves as a robust host material that endows lithium-sulfur batteries with a high reversible capacity of 1115 mAh g(-1) at 0.2 C after 100 cycles, superior rate capability, and excellent cycling stability with 679.2 mAh g(-1) capacity retention over 700 cycles at 1 C. With sulfur contents of up to 5.0 mg cm(-2), the area capacity remains to be 5.1 mAh cm(-2) after 100 cycles at 0.2 C. The remarkable performance is further resolved via a series of experimental characterizations combined with density functional theory calculations. These results reveal that the ordered mesoporous N-doped carbon-encapsulated graphene framework acts as the ion/electron transport highway with excellent electrical conductivity, while bimetallic CoNi nanoparticles enhance the polysulfides adsorption and catalytic conversion that simultaneously accelerate the multiphase sulfur/polysulfides/sulfides conversion and inhibit the polysulfides shuttle.

Automated summary

A novel 2D mesoporous N-doped carbon nanosheet with confined bimetallic CoNi nanoparticles sandwiched graphene has been successfully fabricated as a host material for lithium-sulfur batteries. This material exhibits high reversible capacity, superior rate capability, and excellent cycling stability. The remarkable performance is attributed to the ordered mesoporous N-doped carbon framework and the adsorption and catalytic conversion abilities of bimetallic CoNi nanoparticles.