Sepiolite as a Novel Polysulfide Trapper for energy applications: an Electrochemical, X-ray Spectroscopic and DFT study

GARCIA-SORIANO, FRANCISCO JAVIER; CEPPI, SERGIO ANDRES; COMETTO, FERNANDO PABLO; PRIMO, EMILIANO; BARRACO, DANIEL; LEIVA, EZEQUIEL; LUQUE, GUILLERMINA L.; STUTZ, GUILLERMO; LENER, GERMAN; BRACAMONTE, VICTORIA

PHYSICAL CHEMISTRY CHEMICAL PHYSICS

ROYAL SOC CHEMISTRY

Año: 2023

1463-9076

apacity retention is a critical property to enhance in electrochemical storage systems applied to renewable energy. In lithium-sulfur (Li-S) batteries, the capacity fade resulting from the shuttle effect of polysulfides is a major obstacle to their practical application. Sepiolite, an eco-friendly earth-abundant clay with suitable surface chemistry for anchoring and retaining various molecules and structures, was studied as a cathode additive to mitigate the shuttle effect using experimental and theoretical approaches. Electrochemical measurements, spectroscopy, and ab-initio calculations were performed to describe the mechanism and interfaces involved in polysulfide retention using 2 wt% of sepiolite as an additive in Li-S batteries. The results showed that the addition of sepiolite significantly improved the capacity retention during battery cycling. Spectroscopic analysis revealed that the effective sepiolite-polysulfide interface was governed by oxidized sulfur species. Additional