Exceptional Lithium Diffusion Through Porous Aromatic Framework (Paf) Interlayers Delivers High

Abstract

Lithium-sulfur batteries offer an attractive energy storage alternative independent of upon critical minerals such as cobalt or nickel.  However, their inadequate stability under long term cycling, and storage capacity on a volumetric basis hamper their uptake.  These limitations can be addressed by seeking to control the formation and crossover of polysulfides, oligomers generated through reaction of solvated sulfur moieties with the lithium anode, and by seeking to restrict the consumption of active materials.  Here, we report the development of a triple-functional carbon molecular sieve (CMS) interlayer. The microporous, polar, and conductive structure of the CMS provides physisorption, chemisorption, and reactivation capabilities concurrently.  Therefore, the soluble polysulfides can be trapped, suppressed from shuttling, and reutilized to not only improve the kinetics of the redox reaction but also hinder the loss of active materials.  As a result, our CMS-based Li-S batteries deliver combined exceptional gravimetric (1282 mAh g-1) and areal (7.05 mAh cm-2) capacities at 0.1 C rate as well as cycling stability up to 1000 cycles at 0.2 C rate over 9 months.

Keywords: Carbon molecular sieve, Lithium-sulfur battery, membrane, nanoporous material.