title: Characterization of Sulfur and Nanostructured Sulfur Battery Cathodes in Electron Microscopy Without Sublimation Artifacts.
abstract: Lithium sulfur (Li-S) batteries have the potential to provide higher energy storage density at lower cost than conventional lithium ion batteries. A key challenge for Li-S batteries is the loss of sulfur to the electrolyte during cycling. This loss can be mitigated by sequestering the sulfur in nanostructured carbon-sulfur composites. The nanoscale characterization of the sulfur distribution within these complex nanostructured electrodes is normally performed by electron microscopy, but sulfur sublimates and redistributes in the high-vacuum conditions of conventional electron microscopes. The resulting sublimation artifacts render characterization of sulfur in conventional electron microscopes problematic and unreliable. Here, we demonstrate two techniques, cryogenic transmission electron microscopy (cryo-TEM) and scanning electron microscopy in air (airSEM), that enable the reliable characterization of sulfur across multiple length scales by suppressing sulfur sublimation. We use cryo-TEM and airSEM to examine carbon-sulfur composites synthesized for use as Li-S battery cathodes, noting several cases where the commonly employed sulfur melt infusion method is highly inefficient at infiltrating sulfur into porous carbon hosts.
authors.affiliation: 1School of Applied and Engineering Physics,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Barnaby D A
authors.initials: BD
authors.lastname: Levin
authors.affiliation: 1School of Applied and Engineering Physics,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Zachman
authors.affiliation: 2Department of Materials Science and Engineering,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Jörg G
authors.initials: JG
authors.lastname: Werner
authors.affiliation: 2Department of Materials Science and Engineering,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Ritu
authors.initials: R
authors.lastname: Sahore
authors.affiliation: 1School of Applied and Engineering Physics,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Kayla X
authors.identifier: 0000-0001-9253-7064
authors.initials: KX
authors.lastname: Nguyen
authors.affiliation: 1School of Applied and Engineering Physics,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Yimo
authors.initials: Y
authors.lastname: Han
authors.affiliation: 2Department of Materials Science and Engineering,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Baoquan
authors.initials: B
authors.lastname: Xie
authors.affiliation: 2Department of Materials Science and Engineering,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Lin
authors.initials: L
authors.lastname: Ma
authors.affiliation: 3School of Chemical and Biomolecular Engineering,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Lynden A
authors.initials: LA
authors.lastname: Archer
authors.affiliation: 2Department of Materials Science and Engineering,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Emmanuel P
authors.initials: EP
authors.lastname: Giannelis
authors.affiliation: 2Department of Materials Science and Engineering,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Wiesner
authors.affiliation: 1School of Applied and Engineering Physics,Cornell University,Ithaca,NY 14853,USA.
authors.forename: Lena F
authors.initials: LF
authors.lastname: Kourkoutis
authors.affiliation: 1School of Applied and Engineering Physics,Cornell University,Ithaca,NY 14853,USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Muller
keywords: Cryo-TEM; airSEM; battery; energy; lithium sulfur