Kaolinite nanoscroll significantly inhibiting polysulfide ions shuttle in lithium sulfur batteries

Abstract

The shuttling effect of polysulfide ions is an important reason that hinders the commercial application of lithium‑sulfur batteries. The natural clay mineral halloysite has good adsorption performance and hollow tubular structure, which can absorb and accommodate enough sulfur, while the flake kaolinite can roll to form a halloysite-like structure. The effect of acid-modified halloysite and kaolinite nanoscrolls as sulfur carriers on the performance of lithium‑sulfur batteries was studied in this paper. As a result, both acid-modified halloysite and kaolinite nanoscrolls could effectively adsorb polysulfide ions, while kaolinite nanoscrolls were more conducive to the migration and diffusion of Li+ due to its thinner wall (about 5 nm), thus exhibiting faster reaction kinetics and higher sulfur utilization, and had better rate performance and cycle stability. The application of clay minerals in the field of energy has always been unpromising. This research work makes full use of the characteristics of clay minerals and broadens its application, providing a basis for the design of clay minerals and a possible modification direction for their application in lithium‑sulfur batteries.