title: Cathode composites for Li-S batteries via the use of oxygenated porous architectures.
abstract: Li-S rechargeable batteries are attractive for electric transportation because of their low cost, environmentally friendliness, and superior energy density. However, the Li-S system has yet to conquer the marketplace, owing to its drawbacks, namely, soluble polysulfide formation. To tackle this issue, we present here a strategy based on the use of a mesoporous chromium trimesate metal-organic framework (MOF) named MIL-100(Cr) as host material for sulfur impregnation. Electrodes containing sulfur impregnated within the pores of the MOF were found to show a marked increase in the capacity retention of Li-S cathodes. Complementary transmission electron microscopy and X-ray photoelectron spectroscopy measurements demonstrated the reversible capture and release of the polysulfides by the pores of MOF during cycling and evidenced a weak binding between the polysulphides and the oxygenated framework. Such an approach was generalized to other mesoporous oxide structures, such as mesoporous silica, for instance SBA-15, having the same positive effect as the MOF on the capacity retention of Li-S cells. Besides pore sizes, the surface activity of the mesoporous additives, as observed for the MOF, appears to also have a pronounced effect on enhancing the cycle performance. Increased knowledge about the interface between polysulfide species and oxide surfaces could lead to novel approaches in the design and fabrication of long cycle life S electrodes.
authors: LRCS, UMR CNRS 6007, Université de Picardie Jules Verne, 33 Rue Saint-Leu, 80039 Amiens cedex, France.
authors: Rezan
authors: R
authors: Demir-Cakan
authors: Mathieu
authors: M
authors: Morcrette
authors: Farid
authors: F
authors: Nouar
authors: Carine
authors: C
authors: Davoisne
authors: Thomas
authors: T
authors: Devic
authors: Danielle
authors: D
authors: Gonbeau
authors: Robert
authors: R
authors: Dominko
authors: Christian
authors: C
authors: Serre
authors: Gérard
authors: G
authors: Férey
authors: Jean-Marie
authors: JM
authors: Tarascon