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.
Original language | English |
---|---|
Pages (from-to) | 153-162 |
Number of pages | 10 |
Journal | Microscopy and Microanalysis |
Volume | 23 |
Issue number | 1 |
DOIs | |
State | Published - Feb 2017 |
Externally published | Yes |
Funding
This project was supported by the Energy Materials Centre at Cornell, an Energy Frontier Research Centre funded by the US Department of Energy, Office of Science, BES Award DE-SC0001086; and the New York State Centre for Future Energy Systems (CFES), a joint Center for Advanced Technology between Cornell University and Rensselaer Polytechnic Institute, supported by the New York State, Empire State Development Division of Science, Technology and Innovation (NYSTAR), under contract number C100126. This work made use of the Cornell Centre for Materials Research Shared Facilities which are supported through the NSF MRSEC program (DMR-1120296). The authors thank John Grazul for assistance in the TEM facilities.
Keywords
- AirSEM
- Battery
- Cryo-TEM
- Energy
- Lithium sulfur