Strings of Porous Carbon Polyhedrons as Self-Standing Cathode Host for High-Energy-Density Lithium-Sulfur Batteries.

Abstract

Rational design of cathode hosts with high electrical conductivity and strong sulfur confinement is a great need for high-performance lithium-sulfur batteries. Herein, we report a self-standing, hybrid-nanostructured cathode host comprised of metal-organic framework (MOF)-derived porous carbon polyhedrons and carbon nanotubes (CNTs) for the significant improvement of both the electrode cyclability and energy density. The strong coupling of the intertwined CNTs and strung porous carbon polyhedrons as a binder-free thin film significantly enhances the long-range electronic conductivity and provides abundant active interfaces as well as robust electrode integrity for sulfur electrochemistry. Attributed to the synergistic combination of the CNTs and carbon polyhedrons, the obtained sulfur electrodes exhibit outstanding cyclability, an excellent high-rate response up to 10 C, and an ultra-high volumetric capacity of 960 Ah L-1 .